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CORPS OF ENGINEERS, U. S. ARM'VJtt. ••

21

MISSISSIPPI RIVER COMMISSION

SOIL COMPACTION INVESTIGATION

REPORT NO.1

COMPACTION STUDIES ON CLAYEY SANDS

TECHNICAL. MEMORANDUM NO. 3-,271

WATERWAYS EXPERIMENT STATION

VICKSBURG, MISSISSIPPI

PRICE $1.00

APRIL. 1949

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4. TITLE AND SUBTITLE Soil Compaction Investigation: Report No. 1: Compaction Studies onClayey Sands

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7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) U.S. Army Corps of Engineers,Waterway Experiment Station,3903 HallsFerry Road,Vicksburg,MS,39180

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Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18

CORPS OF ENGINEERS, U. S. ARMY

MISSISSIPPI RIVER COMMISSION

SOIL COMPACTION INVESTIGATION

REPORT NO.1

COMPACTION STUDIES ON CLAYEY SANDS

TECHNICAL MEMORANDUM NO. 3-271

WATERWAYS EXPERIMENT STATION

VICKSBURG, MISSISSIPPI

MRC·WE5-100-APRIL 1949

APRIL 1949

Report No. Title Date

1 Compaction Studies On Clayey Sands April1949

PREFACE

This report is the first of a series of reports to be published on

various studies comprising a comprehensive soil compaction investigation.

This investigation was authorized by the Office, Chief of Engineers, in

May 1945 and performed by the Waterways Experiment Station in accordance

with "Instructions and Outline for Soil Compaction Investigation" dated

June 1945.

CONTENTS

PREFACE

PART I: INTRODUCTION •

Purpose of the Study Scope . • • . . . . . Definition of Pertinent Terms

PART II: TEST FILLS ....

Preliminary Survey Work . . • . Location and Preparation of Materials Construction • . . . . . . • . • .

PART III: FIELD SAMPLING AND TESTING

Procedure and Methods ...•••.

PART IV: lABORATORY TESTING OF UNDISTURBED SAMPLES

PART V: RESULTS OF FIELD AND lABORATORY TESTS

Method of Presentation of Test Data •..... Construction-Lift Moisture-Density Data Field In-Place, CBR, Moisture, and Density Test Data CBR, Moisture, and Density Data from Undisturbed Samples

Taken in Cylinders . . . . . . . . . . . Results of Unconfined Compression Tests

PART VI: DISCUSSION OF CBR TESTS •

PART VII: SUMMARY AND CONCLUSIONS

TABLES 1-5

PHOTOGRAPHS 1-24

FIGURES 1-30

1

1 1 3

7

7 10 12

23

23

26

27

27 27 29

30 35

37

4i

SOIL COMPACTION INVESTIGATION

CLAYEY SAND TEST FILLS

PART I: INTRODUCTION

1. Presented herein are the results of a combined field and lab-

oratory study on the compaction and stress-strain characteristics of a

clayey sand. This study is a part of a comprehensive soil compaction

investigation approved by the Office, Chief of Engineers, in May 1945,

and performed by the Waterways Experiment Station in accordance with

"Instructions and Outline for Soil Compaction Inveatiga'tion" dated June

1945. This report is the first of a series of reports to be published

on the various phases of the comprehensive investigation.

Purpose of the Study

2. The specific purposes of this phase of the investigation are

stated in subparagraphs 2-b and 2-c of the "Instructions and Outline"

as follows:

"2-b. Determination of the stress-strain characteristics of soils compacted in the field by equipment now readily available for compaction purposes.

"2-c. Determine the feasibility of the utilization of field compaction equipment of types now generally in use to obtain much greater compaction than is now generally required in fills."

Scope

3. The results of the investigation described in this report

2

provide a partial realization of the above-stated purposes. Objective "2-b"

was not completely realized inasmuch as only CBR and unconfined compres-

sion tests were performed. Triaxial compression tests were scheduled but

could not be performed because the samples could not be protected from

high summer temperatures and cracked and dried out. Additional work is

required to completely realize objective "2-c" because certain factors

that affect compaction were held constant in this investigation and must

be made variable in future work so that a complete determination of the

effect of all factors influencing compaction will be accomplished. Brief-

ly, the study was to consist of the following phases of work:

a. Preliminary survey work to locate a source of clayey sand material, and tests to determine the physical characteris­tics of various clayey sand mixes under dynamic and static compaction in the laboratory.

b. Construction of test fills of clayey sand using the follow­ing types of equipment for compaction: 34,500-lb D-8 tractor; a sheepsfoot roller loaded to produce 250, 450, and 750 psi; 19,500-lb wobble-wheel roller (1500 lb per wheel); 10,000-, 20,000-, and 40,000-lb rubber-tired wheel loads.

c. Field sampling and testing of test fills.

d. Laboratory tests on undisturbed samples procured from the test fills.

The variables present in any compaction work on a given soil with a given

type of equipment are: (1) weight of roller, (2) contact pressure, (3)

number of coverages, and (4) thickness of lifts. Items (1), (2), and, to

-a limited extent, (3) were investigated for compaction by sheepsfoot

rollers. Item (l) was investigated for compaction by rubber-tired

rollers. The other variables mentioned above but not investigated were

outside the scope of the tests described in this report.

Definition of Pertinent Terms

4. For purposes of clarity, various terms used in this report are

defined as follows:

3

Unit. A unit or test unit consists of an area of natural sub­

grade or a portion of a compacted fill which is compacted during the test

at a given water content and under a given compactive effort with a given

piece of compacting equipment.

Section. A section (usually several units) is an area of natu­

ral subgrade or a portion of a compacted fill constructed using one com­

pactive effort at several water contents. A section, therefore, consists

of a test area which is utilized in determining all or a part of a

compaction curve for a given number of passes of a given piece of com­

pacting equipment.

Compactive effort. This term can apply to either field or

laboratory compaction. In the case of laboratory compaction a compactive

effort consists of the application of a given amount of energy per unit

volume of compacted soil. The compactive effort can be varied in the

laboratory by changing the weight of the compacting hammer, number of

blows per layer, or number of layers of soil in the compaction cylinder.

In the case of field compaction a compactive effort consists of compaction

by a given piece of equipment passing a given number of times on a given

thickness of lift.

Trip. A trip of the compacting equipment refers to the pass­

age of the equipment from one end of the compacted section to the other

in one direction only. The term "round trip" is used for designation of

a trip from one end of the section to the other and back.

4

Coverage. One coverage consists of one application of either

a wheel of a rubber-tired roller or a foot of a sheepsfoot roller over

each point in the area being compacted.

Pass. For a rubber-tired roller, pass and coverage are syn­

onymous. For a sheepsfoot roller, one pass consists of one movement of

a sheepsfoot roller drum over the area being compacted. The sheepsfoot

roller used in this investigation re~uired about 18 passes to accomplish

one coverage.

Sheepsfoot roller. A double-drum, oscillating sheepsfoot roller,

Model AD-132, manufactured by the American Steel Works. By loading the

drums with increasing amounts of Baroid, foot contact pressures of 250 and

450 psi were obtained with one row of feet in contact with the ground.

Each drum is 60 in. in diameter and has eight 7-in.-long feet in a row.

The area of each foot is 7 s~ in.

Wobble-wheel roller. This term applies to a wobble-wheel roll­

er loaded to 1495 lb per wheel on 13 wheels, or 19,440 lb gross weight.

Tires were inflated to a pressure of approximately 40 psi. This roller is

referred to hereafter as a 1500-lb wobble-wheel roller.

20,000-lb wheel load. This load was furnished by a Model Super

C Tournapull of 12-cu-yd capacity loaded to a gross weight of 80,000 lb,

or 20,000 lb per tire. Tires were inflated to a pressure of approximately

55 psi; contact pressure was approximately 65 psi; and contact area was

approximately 308 s~ in.

40,000-lb wheel load. This load was furnished by a Tournapull

of 32-cu-yd capacity, loaded to a gross weight of 160,000 lb, or 4o,ooo

lb per tire. Tires were inflated to a pressure of approximately 57 psi;

contact pressure was approximately 69 psi; and contact area under this

load was 580 sq in.

5

California Bearing Ratio or CBR. A measure of shearing resist­

ance of soils to penetration which is determined by comparing the bearing

value obtained from an arbitrary penetration-type shear test with a stand­

ard bearing value obtained on crushed rock (average value of a large number

of tests). The standard results are taken as 100 per cent and values ob­

tained from other tests are expressed as percentages of the standard. CBR

may be modified by the terms laboratory, field in-place, soaked or unsoaked,

according to conditions under which the testa were made; or by the terms

design or evaluation, according to the purpose for which the test results

will be used.

D,ynamic compaction. Compaction of soil by the impact of a free­

falling weight or hammer.

Static compaction. Compaction of soil by gradually increasing

the compacting pressure, applied by means of a piston covering the entire

surface of the specimen, up to any given amount. In the Porter static

compaction method this pressure is 2000 psi.

Standard AASHO compaction. In this report it is assumed that a

soil material is compacted by standard AASHO effort so long as the effort

or-work expended per unit volume of compacted soil is the same as that

specified by standard AASHO method T-99-38. In order to perform CBR

tests on compacted material and to study the effect of mold size, the

standard AASHO equipment and methods were varied. However, in all cases

the effort expended per unit volume of compacted soil is the same.

Modified AASHO compaction. A modification by the Corps of

6

Engineers of the standard AASHO compaction method, consisting of dynamic

compaction in a CBR mold (6-in. diam) using 55 blows of a 10-lb hammer

ralling 18 in. on each of five equal layers. In this report the size of

mold was increased to study the effect of mold size, and the number of

blows was increased accordingly. The work expended per unit volume of

soil was the same in all size molds.

7

PART II: TEST FILlS

Preliminary Survey Work

5. Several possible sources of the clayey sand material in the

immediate vicinity of Vicksburg were explored and samples of the material

were tested in the laboratory for determination of compaction and CBR

characteristics. It was found that none of these materials satisfied

requirements of a low-swelling clayey sand of low to medium plasticity.

A pit was finally located near Clinton, Mississippi, about 40 miles east

of Vicksburg, which satisfied the specifications for the type material

desired for test fills. The borings indicated that, in-general, the pit

had approximately 1 to 6 ft of clayey silt overburden, underlain by ap­

proximately 2 ft of clayey sand containing 65-80% sand, which, in turn,

was underlain by a layer of clayey sand more than 20 ft in thickness con­

taining approximately 80-90% sand. Trial mixes of the two clayey sands

were investigated in the laboratory and it was found that a blend of

approximately 20% of the material containing 65-80% sand and 80% of the

material containing 80-90% sand would yield a satisfactory material for

test purposes.

6. Classification data for this material are shown on fig. 1 from

which it can be seen that the blended material has a uniform gradation

in the fine and medium sand sizes and a plasticity index of approximately

2. Soil similar to this type of material is found in much of the south­

eastern United States and has been used to a considerable degree as a

base course material in highway and airport construction. The material

has also been used to a great extent as surfacing on secondary roads.

8

7· The results of dynamic and static laboratory compaction and CBR

tests on the clayey sand in the unsoaked and soaked condition are shown

on figs. 2-5. A series of unconfined compression tests on specimens com­

pacted dynamically and tested in the unsoaked condition were also performed

on this material, the results of which are shown on fig. 6. It can be

noted by reference to fig. 2 that modified AASHO maximum dry density is

approximately 122 lb per cu ft at an optimum water content of 10%, and

that standard AASHO maximum dry density is approximately 116 lb per cu ft

at an optimum water content of 11.5%· The corresponding CBR values for

these two compactive efforts are 65 and 15, respectively, in the unsoaked

condition (fig. 2). and 47 and 15, respectively, for the soaked condition

(fig. 3).

8. According to Part XII, Chapter 2, of the Engineering Manual,

this material if used as a base course would generally be required to be

compacted to 95% of modified AASHO maximum density at modified AASHO op­

timum water content. For this condition, which is 116 lb per cu ft dr,y

density at 10% water content, the unsoaked CBR is 27, whereas the soaked

CBR is 22. It is interesting to note that under 2000-psi static com­

paction, which is the original Porter or California method of compaction,

this material has an optimum water content of approximately 13% and a

maximum dry density of 112 lb per cu ft. The unsoaked CBR for the 2000-

psi static compaction is 17, whereas the soaked CBR is 19. The reason for

the soaked CBR being higher than the unsoaked CBR is the manner in which

the statically compacted specimens are prepared for test purposes. Ini­

tially the material is placed in the CBR mold and compacted by one applica­

tion of the piston under 2000 psi. The top of the specimen is then

9

subjected to a CBR penetration teat. A maximum dr,y density of 112 lb per

cu ft, an optimum water content of 13%, and an unaoaked CBR of 17 resulted

from this penetration procedure. After penetrating the top of the apeci-

men, the top inch of the material is scarified and a base plate placed on

top of the mold. The mold is inverted and the 2000-pai load reapplied on

what was previously the bottom of the specimen as initially compacted.

This additional compaction increased the average density of the mold up

to about 114 lb per cu ft, while still at the same optimum water content

of 13%. The material is then allowed to soak, at the end of which time a

CBR penetration test is performed. This test resulted in a value of 19%-

For convenience and ready comparison of densities, water content, and CBR

values, these data are tabulated as follows:

Maximum Opt. Unconfined Type of Dry w .c. Compressive Strength

Compactive Density Per CBR in Per Cent Lb per Sq In. Effort LbLCu Ft Cent Unsoaked Soaked Unsoaked

Modified AASHO 122 10 65 47 20

95% Modified AASHO

116 10 27 22 12

Standard AASHO 116.4 11.5 15 15 10

Porter static 112 13 17 (2000 psi) 114.5* 13 19

111 13 3

*High density value due to recompaction as discussed in paragraph 8.

9. It can be noted by reference to the above tabulation that the

CBR at 95% modified AASHO density is less than one-half of that obtained

at modified AASHO density. Under standard AASHO density ~he CBR is only

about one-fourth of that obtained under modified AASHO density. Also,

10

under modified AASHO the unconfined compressive strength is 20 psi in

the unsoaked condition, 12 psi at 95% of modified AASHO density, and 10

psi under standard AASHO density. The unsoaked CBR value of 17 obtained

on specimens compacted under 2000-psi static compaction is in the general

range of that obtained under standard AASHO compactive effort, but the

unconfined compressive strength of 3 psi is much lower than that ob­

tained for standard AASHO effort.

Location and Preparation of Materials

Location of test site

10. Because of the proximity of the clayey sand pit to the Clinton,

Mississippi, Sub-Office of the Waterways Experiment Station, it was de­

cided to construct the test fills on a portion of this reservation.

Pit operations

11. A total of approximately 15,000 cu yd of clayey sand mate­

rial was needed for the tests. After stripping, it was found that soil

variations occurred rather frequently but that in general the soil con­

sisted of the two types discussed in paragraph 5. According~y, the mate­

rial was examined at the borrow pit by an inspector, who classified the

material as one or the other of the two basic types of clayey sand. The

soil was excavated by a dragline using a 1/2-cu-yd drag bucket and trans­

ported to the test site by from three to six trucks of 3-cu-yd capacity.

Stock piles

12. The two clayey sand materials were stock-piled in adjoining

areas at the field site. The material was spread on each stock pile in

11

thin layers, approximately 3 in. thick, with four-directional blading to

produce intimate mixing and to crush out lumps. The water content of the

interior of both stock piles remained close to 10%. It was necessary to

air-dry the materials to reduce the water content to approximately 7% so

that the material would flow freely through the batching bins of the

mixing plant. Spreading and windrowing accelorated the drying. This

air-dried clayey sand was piled in the areas adjacent to the mixing plant.

During the latter part of the construction period an aggregate drier was

used to accelerate drying of the clayey sand for use in the dry units of

sections 8 and 9.

Mixing plant

13. The mixing plant consisted of a two-compartment aggregate bin

with a three-beam batching scale mounted above a pugmill driven by a

Diesel engine. A spray bar was installed over the pugmill and connected

to a water batching tank with manual controls and gage. Clayey sand was

loaded into the bins by a dragline equipped with a 1/2-cu-yd clamshell . bucket. The clayey sand batch was weighed out and dumped into the pugmill.

Water was added during the first part of the mixing period while the next

batch was being weighed. The size of the batch was established at 1250 lb

dry weight, which was sufficiently below the pugmill capacity to allow

operation at a uniform speed. Batch weights were computed on a dr,y basis

so that the setting of the scales was changed only with changes in the

stock-pile water contents and not with changes in the batch water content.

The plant produced 50 to 55 batches an hour when the stock-pile materials

were dry enough to flow freely. As the water content of the materials

12

increased from 6% to 8 or 9%, sticking and bridging acted to slow down

the :production.

Construction

Layout

14. The test sections as actually constructed are shown on the lay-

out on fig. 7. It can be noted that similar sections were :placed in the

same test area. This :permitted simultaneous construction of one section

of each ty:pe without traffic congestion. The ram:p and shoulder limits

were :placed to allow shoulder slo:pes of approximately 1 on 5 and ram:p

slo:pe of 1 on 10. A 20-ft transition of clayey sand was placed between

the ram:ps and the end units of the test section to receive the carry-

over of :pit materials and to permit the entry of compaction equipment

into the first unit at proper s:peed. Allowance was made on the 20,000-

and 40,000-lb wheel load sections for the large turnarounds required by

the Tourna:pulls. The test section number together with the type and

number of :passes of compaction equipment used is summarized below.

Test Section Compactive Effort in Construction Number Width-Ft Length-Ft Equipment Used No. of Passes

2 50 200 450-:psi shee:psfoot 9

3 40 200 250-:psi sheepsfoot 9

5* 30 200 D-8 tractor 3

6** 30 200 1500-lb wobble-wheel 6

8 30 200 20,000-lb wheel load 4

9 40 200 40,000-lb wheel load 4 on 1/2 section 8 on 1/2 section

* Section 5 constructed 2 ft high; all others 5 ft. ** Section 6 constructed in 3-in. lifts; all others constructed in 6-in.

compacted lifts.

13

It was originallY intended to construct a section with a 750-psi sheeps­

foot roller and a section with an 8,000-lb wheel load. These sections

were eliminated however in the latter part of the program for reasons

that are discussed in paragraph 47.

Ground-water conditions

15. At the start of field construction in June 1945, the ground-

water table at the test areas was from 3 to 4 ft below the surface. In

October the depth to ground water was greater than 6 to 7 ft. This

change may be accounted for by normal seasonal fluctuation.

Subgrade preparation

16. The site was first cleared of brush and a system of connecting

surface drainage ditches was built. The subgrades of the test areas were

stripped of root-bearing topsoil and were scarified with a 24-in. disk

and a Killifer plow. The water content of the subgrade soil was gener-

ally above its standard AASHO optimum, and the areas were left to dry

during the period of clayey sand borrowing. From time to time they were

opened up, aerated, and resealed. It was finallY necessary to remove

1100 cu yd of wet subgrade soil and to replace it with material at a

lower water content. Compaction of the refill material was performed

with a tractor and wobble-wheel roller and the compacted areas were bladed

to finished grade with a motor patrol. This procedure resulted in a firm

subgrade satisfactory for the compaction test fills. All of the test .

areas were finished with slopes adequate' for the quick drainage of rain-

fall, using the natural ground surface to maximum advantage. Prior to

placing the first lift of clayey sand the subgrade surface was wetted to

14

restore proper moisture conditions.

Operation of compaction equipment

17. Sheepsfoot rollers. One sheepsfoot roller, an American Steel

Works Model AD-132, was used in order to obtain the unit foot pressures

required in construction of the clayey snnd sections. The operating speed

for all compaction equipment was first established at 3 mph. It was

desired to have the test sections compacted so as to cover a range of

density from approximately 95% of standard AASHO maximum density to

greater than 100% modified AASHO density, if possible. The nUmber of

passes to bo made with the 250- and 450-psi weights of sheepsfoot roller

was therefore selected by preliminary experimental tests with the 250-psi

roller. It was desired to approximate 95% of standard compaction with

this roller. A unit consisting of three 6-in. lifts was constructed

using the clayey sand at approximately standard AASHO optimum water con-

tent and compacted in lanes using 6 to 18 passes; The densities produced

in this unit were as follows:

Number Dry Density Water Content of Passes Lb[Cu Ft Per Cent

6 108.2 11.4· 9 110.3 11.4

12 112.0 12.0 15 113.4 12.5 18 114.3 11.2

The standard AASHO optimum density of the clayey sand was approximately

ll6 lb per cu ft. The number of passes constituting the sheepsfoot roller

efforts was established on the basis of these 250-psi data as nine, which

gave approximately 95% of standard AASHO density or 110 lb per cu ft.

15

The nine passes were performed in two series of trips; in the first aeries

the roller was offset one tractor tread width (22 in.) each trip. Thus,

when the tractor progressed completely across the section, the area had

received two coverages of the tractor and six passes of the roller; the

second series, offset two tread widths (44 in.) each trip, produced the

remaining three passes of the roller.

18. It has been stated previously that the nominal or "rated"

pressure intensity of sheepsfoot rollers is customarily computed with one

row of feet in contact with the ground. This condition seldom if ever

exists during actual operation. When the feet penetrate the soil more

feet come in contact with the ground and the contact pressure may be

reduced. For example, if the feet of the roller used in these tests

penetrate the ground to such an extent that the drum of the roller just

touches the ground, then the extremities of 24 teeth are below the sur­

face of the ground. A penetration of only 4 in. will place the ex­

tremities of 16 feet below the ground surface.

19. The distribution of the forces involved on the different rows

of feet of the roller is not known but is probably quite complex. It

is probable that the feet emerging from the soil carry no load whatever

on the face of the foot, but may have a pressure on the shank of the foot

due to a "kicking" action discussed in a later paragraph. The load car­

ried by the feet as they penetrate the soil undoubtedly varies over wide

limits. It is probable that, with the roller in normal operation, a por­

tion of the force required to pull the roller acts principally on the

feet that are forward of the center of the drum and in contact with the

soil. This force, while dependent on the weight of the drum, is an

16

addition to theforcesdeveloped by the dead weight of the drum acting

alone.

20. The greatest possible load that could be carried by the feet

occurs, during normal rolling operations, when the soil is so compact

that only one row of feet is in contact with the soil. The least possible

axial load applied to a row of feet during normal rolling operations would

result if the following assumptions are made: (1) the feet emerging from

the soil carry no load; and (2) each foot below and forward of the center

of the drum in contact with the soil carries an equal axial load. For the

roller used, six rows of feet are in contact with the soil when the drum

just touches the ground. Three rows of feet are emerging and are assumed

to carry no load. Three rows of feet are thus carrying the load and the

axial pressure is therefore one-third of the rated foot pressure.

21. Another factor to be considered that affects the performance

of a sheepsfoot roller, as explained below, may be called the effective

or pitch diameter. The effective diameter is determined by observing the

number of revolutions of the roller required for the roller to traverse

a given distance. It is probable that the effective diameter is not con­

stant for a given roller but varies with the type of soil, water content,

and depth of penetration of the feet.

22. The drum of the roller used in this study was 66 in. in length

and 60 in. in diameter. The length of feet was 7 in., making the over­

all diameter 74 in. There were 120 feet on the drum (30_rows at four

feet per row), and the end area of a foot was 7 sq in. If the effective

radius is taken as 37 in., one-half the over-all diameter, then the area

of a cylinder with a 37-in. radius and a 66-in. length is about 15,300

17

sq in. The total foot area is 840 sq in. so that the foot area is about

5-5% of the total area and about 18 passes of the roller are required

for one coverage.

23. It can be shown graphically, by construction of a cycloid,

that the feet of a roller enter and emerge from the soil in an almost

vertical position if the effective radius is taken as the distance from

the center of the drum to the outer end of the foot. Further, the roller,

in effect, pivots about the end of the foot directly beneath the center

of the drum and there is no relative horizontal movement between the face

of the foot and the ground. However, if the radius of the drum is taken

as the effective diameter, then the feet make a greater angle with the

vertical when they penetrate and emerge from the soil. Also, the pivot

point is now not at the outer end of the foot but at the point where the

foot joins the drum. The face of the foot now moves horizontally with

respect to the ground; the movement is to the roar, resulting in a kicking

or shovel action. It is reasonable to suppose that a greater force would

be required to tow the roller in the latter case. The actual effective

diameter probably lies between the two extreme values just pointed out.

24. It was stated in the preceding paragraph that the effective

diameter determined the position of the foot with respect to the vertical

as it entered and emerged from the soil. If the position from the ver­

tical is appreciable, the side of the shank will contact the soil when

entering or emerging. This fact further complicates the computation of

actual foot pressures. If the side of the foot or the shank contacts the

soil they will carry some part of the load and the pressure on the face

of the foot (paragraph 18) will be further reduced.

18

25. Inasmuch as the feet always penetrate into the ground a cer-

tain distance it is obvious from the discussion presented in the preceding

paragraphs that when a layer of soil is compacted the pressure intensity

on the face of the foot is not equal to the nominal or rated pressure,

nor has the 1ayer received a complete coverage with the number of passes

used in the test. The stress developed in the soil beneath a roller foot

diminishes with depth below the face of the foot but, at the same time, the

area stressed increases. Thus, at some depth the areas subjected to stress

from adjacent feet on the roller begin to overlap and a complete coverage

results. However, the pressure intensity on the plane of such a complete

coverage is much less than the pressure at the face of the foot.

26. Pneumatic-tired rollers. It was desired that the equipmen~ used

for each wheel load should be capable of exerting approximately the same

contact pressure on the fill being compacted and the range of densities

desired was to be the same as that specified for the sheepsfoot rollers

(paragraph 17). The number of coverages to be made with the pneumatic-

tired rollers was therefore selected by constructing and testing an

experimental unit similar to that constructed with the 250-psi sheepsfoot

roller. The range of densities obtained in the clayey sand with a tire

load of 8000 lb is shown below:

Number Dry Density Water Content of Coverages LbLCu Ft Per Cent

2 111.8 14.0 4 114.'0 12.5 6 115.8 12.6

.8 116.1 12.1

These data indicate that two coverages of this wheel load produced a

19

density slightly greater than 95% of standard AASHO optimUm. However, in

the interest of obtaining uniform compaction, the tire-load efforts were

established at four coverages. Tire-load compaction was performed by

moving the equipment over one tire~print width per trip, the outside wheel

track thus meeting the inside wheel track.

27. Wobble-wheel roller. Compaction with the 1500-lb wobble-wheel

roller load was performed using six coverages in accordance with the

directive.

28. Tractor. Compaction with the 34,500-lb D-8 tractor was per­

formed using three coverages, which was the number of tractor coverages

made in pulling the sheepsfoot roller nine passes, as discQssed in the

latter part of paragraph 17.

Fill construction

29. General. The clayey sand sections were built in the following

order:. (l) section 6, 1500-lb wobble-wheel load; (2) section 3, 250-psi

sheepsfoot; (3) section 5, 34,500-lb tractor; (4) section 2, 450-psi

sheepsfoot; (5) section 9, 40,000-lb wheel load; and (6) section 8,

20,000-lb wheel load. Mixing and placing of the material were continuous

during two 10-hr shifts, with two sections being worked simultaneously.

Compaction was carried out during daylight hours. The five units of each

section, planned to bracket the optimum water content of the clayey sand,

were arranged with water content increasing from south to north, down­

slope. In the sections adjoining shoulders (sections 3, 5, 6 and 8) each

unit was entered directly from the shoulder, so that a minimum amottnt of

compaction would be caused by filling and spreading operations. For the

same reason, the interior sections (sections 2 and 9) were reached by the

20

end ramps, and filling progressed from the center unit to the ends.

Ramps and shoulders were brought up level with fills and were built by a

scraper with subgrade soil from nearby shallow borrows. No surfacing was

used on ramps and turnarounds.

30. Protective surface covering. .Each section was protected from

excessive evaporation and from rainfall by covering throughout the con­

struction period. While allowance for evaporation was made in the mixing

water, the length of exposure was variable and unpredictable. The covers

used were 18 by 42 ft and 18 by 52 ft and were made of prefabricated bitu­

minous surfacing (PBS) which was available in rolls 300 ft long and 3 ft

wide.

31. Placement procedure. Operations were begun with water content

determinations on the material ready for placement in the plant hoppers

and computation of batch quantities. The subgrade of the unit to be

built was uncovered and mixing and hauling started. The water content of

the mix was checked by grab samples from the second load and from every

eighth to ninth load thereafter. On the fill, each load was dumped in a

pattern based on the quantity of clayey sand computed for the unit lift

and the 2500-lb truck load. The material was spread and leveled by bull­

dozers as soon as placed. A light tractor bulldozer was used in sections

3 and 6; a D-7 tractor bulldozer was employed in the other sections. Bull­

dozers were used in preference to a motor patrol for this work, because of

their better maneuverability and low contact pressure. As rapidly as the

material was spread, the PBS covers were replaced, to remain until the

entire section was ready for compaction.

32. Compaction. Immediately prior to compaction the entire section

21

was uncovered and plowed with one pass of a Killifer plow, one pass of a

Seaman pulvimixer, and a second pass of the Killifer, as shown in photo-

graph 1. The water content of the loose layer was checked in samples from

the center of each quarter of each unit. In a few instances water content

adjustment was made by leaving the unit in question exposed while re-

covering the rest, or by sprinkling with a tank truck and repeating the

mixing and testing. The first pass of the compaction equipment followed

the final pass of the Killifer. In a representative number of lifts,

check water content determinations were made after rolling was completed.

When compaction operations were completed the section was again covered

and remained so until placement of the next lift began. After compaction

of the last lift in each section, the surface was dressed with a blade

when necessary and then covered with PBS mat. The compaction of each

section is described below.

a. Section 6 (1500-lb wobble-wheel load pulled b rubber­tired tractor • This section was constructed in 3-in. compacted lifts with average water contents in the units, respectively, of 8, 10, 12.5, 14, and 15.5%. Because trucks and roller bogged down in the wet end of the sec­tion, the water contents were changed beginning with the third lift to 6, 8, 10, 12, and 14%. Compaction of the 14% material was difficult. The rubber-tired tractor and wobble-wheel roller were seldom able to cross this unit without being towed. The material was displaced consider­ably when being rolled, which resulted in a very rough surface condition which had to be graded after each third lift was compacted. A light tractor bulldozer or light motor patrol performed this work.

b. Section 3 (250-psi sheepsfoot roller pulled b D-8 tractor • This section was constructed in -in. com­pacted lifts with average water contents in the units, respectively, of 6, 8, 10, 12, and 14%. In the 12 and 14% materials the roller produced a large degree of springing, and in the 14% material the pickup of material was excessive. The roller appeared to walk out about 3 in. during compaction of the 10 and 12% materials.

22

c. Section 5 (34,500-lb D-8 tractor). Material in this sec­tion was placed in 6-in. lifts at water contents in the various units of 6, 8, 10, 12 and 14%. The D-8 tractor produced some rutting and shoving in the 14% material. Elsewhere the compacted surface was regular. Vibration in the fill due to the moving tractor was much more noticeable than in the fills compacted by the sheepsfoot rollers pulled with the same tractor.

d. Section 2 (450-psi sheepsfoot roller pulled by 34,500-lb D-8 tractor). Material in this section was compacted in 6-in. lifts at water contents in the various units of 6, 7.5, 9, 10.5, and 12%. In the 12% material the roller pro­duced a large degree of springing in the fill and a heavy material pickup. Very little walk-out of the roller during compaction was observed. The appearance of the roller in the different units after the first and last (9th) pass is shown in photographs 2-11.

e. Section 9 (40,000-lb wheel load). Material in this section was compacted in 6-in. lifts at water contents in the various un~ts of 6, 8, 10, 12 and 14%. Although the west half of this section was compacted under four coverages of the wheel load and the east half was compacted under eight coverages of the load, the behavior under load and appearance of the two halves were very similar. The progressive deflection of the fill under this wheel load as the water content increased is shown in photographs 12-16 for the first cov­erage and in photographs 17-21 for the last four coverages. In the 12 and 14% material, the deflections resemble flood waves with the fill in motion for several feet in every direction from the moving wheel. The heavy ruts shown in the 14% material (photographs 16 and 21) were developed progressively but with shifting and reshaping under each successive trip.

f. Section 8 (20,000-lb wheel load). This section was con­structed in 6-in. lifts at water contents in the various units of 6, 8, 10, 12, and 14%. This wheel load produced deflections of somewhat less than 2 in. in the material at 12%, and between 2 and 3 in. in the 14% water content. In the latter, rutting took place and increased with the number of coverages and in rolling it was difficult to keep the compaction equipment in line.

23

PART III: FIEIJ) SAMPLING AND TESTING

33. During construction, water content determinations were made on

the material in each lift, and sufficient density tests made to obtain

preliminary information on the trend of density in several lifts. Follow­

ing construction, density and water content determinations were made at

6-in. intervals throughout the entire depth of fill and test pits staked

in each unit. In each test pit, field in-place CBR tests were performed

at three depths and undisturbed samples in quadruplicate were obtained in

CBR molds and in cubic-foot boxes adjacent to the field in-place CBR tests.

Test pit samples were not taken below a depth of 34 in., as density deter­

minations showed that densities did not increase below a depth of about

12 to 18 in.

Procedure and Methods

34. Samples for the construction-lift water content and density

tests were obtained in thin-walled steel cylinders 3-3/4 in. in diameter

and 5 to 6 in. in length. The cylinders were fitted with a threaded

driving.cap, an extension pipe 1-1/2 in. in diameter, and a pipe cap,

and were driven with 12- or 14-lb sledge hammers. Samples for the density

tests made after construction at 6-in. intervals throughout the depth of

the section were also obtained by this method.

35. The field in-place CBR tests were conducted in accordance with

instructions in Appendix C, "California Bearing Ratio Test as Applied to

the Design of Flexible Pavements for Airports," Waterways Experiment

Station Technical Memorandum 213-1, dated 1 July 1945. The improved

truck-mounted apparatus, with a surcharge weight of 30 lb on a

24

10-in.-diam plate, was used in all tests. CBR tests were made in opposite

corners of the test pit at depths of 3, 12, and 17 in. in section 5

(tractor compaction), and at depths of 3, 12, and 24 in. in the other

sections. The truck was backed over the pit on tracks of pierced plank

landing mat which protected the pit edges and the sample locations from

traffic disturbance. Samples for the density tests made in connection

with the CBR tests were obtained in thin-walled steel cylinders, 3 in.

in diameter and 3 to 3-1/2 in. in length. These cylinders were driven

by the use of a light-weight drop-hammer arrangement. Preliminary tests

showed that no appreciable differences in densities were obtained when

samples of the clayey sand material were taken by a hammer-driven cylin­

der and a hydraulically-driven cylinder. As a result of some compaction

due to driving, samples taken with a hammer-driven cylinder of a material

in a relatively loose condition may have a slight~y higher density than

samples obtained with a hydraulically-driven cylinder or those taken in

test pits as described in the following paragraphs. Because of the greater

ease and rapidity in obtaining samples, the hammer driving was resorted to

in one phase of the test procedure.

36. Undisturbed samples for laboratory tests were obtained in

wooden boxes and cylindrical molds at the same depths that field in-place

CBR tests were performed. The box samples were 9-in. cubes and were

obtained by digging out around a soil pedestal, trimming the pedestal to

an approximate 9-in. cube and encasing it in paraffin and a wooden box.

The cylindrical samples were 6 in. in diameter and 6 in. long and were

obtained in a similar manner, except that the soil pedestal was trimmed·

oversize and a 7-in.-diam cylinder with a 6-in.-diam cutting edge was

25

forced down on the pedestal, so that a true cylinder-shaped sample was

obtained, The annular space between the sample and cylinder was filled

with paraffin and the top of the sample covered with wax paper and sealed

with paraffin. The pedestals were then cut free and the bases trimmed

and sealed with wax paper and paraffin. Typical steps in the sampling

operations are shown in photographs 22 and 23.

26

PART IV: lABORATORY TESTING OF UNDISTURBED SAMPLES

37. As previously mentioned, the undisturbed samples that were ob­

tained in cylindrical molds from the various test units were taken in

duplicate at each elevation where CBR field in-place tests were performed.

Upon receipt in the laboratory, one of these samples was penetrated in

the as-compacted condition, and the second sample was placed in the soak­

ing tank for a period of four days. At the end of the soaking period the

sample was subjected to a CBR penetration test. Density and water con­

tent determinations ·were performed on each sample received in the

cylindrical molds.

38. The undisturbed samples seQured in boxes from the different

test units were used for obtaining specimens for unconfined compression

tests, which were performed on the material in the as-compacted condi­

tion. An effort was made to perform unconfined compression tests on

soaked specimens in order to obtain shear strength data on this type of

material when saturated. At first, however, it was not possible to use

soaked specimens for these compression tests due to the fact that the

specimens fell apart when the paper towel with which they were protected

during soaking was removed. At a later date a different procedure was

used and unconfined compression tests on soaked specimens were success­

fully accomplished. The small un~onfined compression testing device and

sampling apparatus developed by Dr. M. Juul Hvorslev were used for the

performance of these tests. The samples were prepared by letting an

entire box sample soak and then obtaining test specimens from the box

by means of the thin-wall Hvorslev sampler.

27

PART V: RESULTS OF FIELD AND lABORATORY TESTS

Method of Presentation of Test Data

39. All test points from field determinations were plotted and a

smoo~h curve drawn through the points. In all water content-density

plots the curve was quite well defined. Points on the dry side of the

optimum water content were sometimes as much as 3-4 lb per cu ft above

and below the average curve for any given water content, but the varia­

tions were much less on the wet side of optimum. Variations of this

magnitude occurred in spite of the carefully controlled placement pro­

cedures and are to be expected in field-compacted soils; however, good

average values were obtained by making a sufficient number of determina­

tions. Deviations from the average curve were somewhat greater in the

case of CBR data, but the data shown are believed to represent the CBR of

the soil as accurately as may practicably be obtained by means of a test

of this nature.

Construction-Lift Moisture-Density Data

40. As previously indicated, density and water content determina­

tions were made on construction lifts in the test sections as they were

constructed. The results of these tests on five of the test sections

are shown in figs. 8-12 and are typical of the data obtained. These

data are shown in the form of moisture-density curves for different lifts

in a given section. As indicated, the curves shown for a given piece of

equipment were obtained from tests o~ samples obtained at the same time

28

after the construction of a particular lift. For instance, on fig. 9

the typical moisture-density data shown for lifts 3, 4 and 5 were devel-

oped from teat data obtained on samples taken from each of these lifts

immediately after construction of lift 6. In general, the moisture­

density curves for the lifts close to the surface of the fill are more

rounded in the vicinity of optimum water content than those at two to

three lifts below the surface of the fill. It can also be noted that

there is a tendency for the density at optimum water content to increase

slightly with increase in depth down to about 12 to 18 in. At the 18-in.

depth the tractor, 250-pai aheepsfoot roller, and 450-psi sheepsfoot

roller sections all have the same maximum density of about 114 to 115

·lb per cu ft at optimum water content. I

This is equivalent to approximately

94% of modified AASHO maximum density. For these same pieces of equip-

ment at the 18-in. depth the optimum water contents are approximately

13.5, 13 and 11.5% for the tractor and the 250- and 450-psi sheepsfoot

rollers, respectively.

41. In the case of pneumatic-tired equipment, reference to figs.

11 and 12 indicates that the observations regarding shape of compaction

curves and increase in density with increase in depth just pointed out

for the tractor and sheepsfoot rollers appear to hold equally as well

for rubber-tired equipment. In comparing densities for the wobble-wheel

roller at 3-, 6- and 9-in. depths with densities for the 40,000-lb wheel

load, it can be noted that the maximum dry density for the wobble-wheel

roller section (built in 3-in. lifts) and for the 40,000-lb section

(built in 6-in. lifts) is approximately 116 lb per cu ft (95% modified

AASHO density) at a constant optimum water content of approximately 12%.

29

Thus, it appears that pneumatic-tired equipment gives slightly greater

densities for the clayey sand material than the tractor or sheepsfoot

rollers, and it also appears that the equal densities obtained under

pneumatic-tired equipment were obtained at the same optimum water content,

whereas equal densities obtained under the tractor and sheepsfoot rollers

were obtained at varying optimum water contents.

42. It can be noted by reference to figs. 8-12 that, for all prac­

tical purposes, the maximum densities obtained with the different types

of equipment did not show any marked changes beyond a depth of about l2

to 18 in. On this basis it was decided that it would not be necessary to

perform field in-place tests or to take undisturbed samples at depths

greater than 24 to 34 in. Actually, when field sampling and testing

were performed the maximum depth for field CBR tests was approximately

24 in., but density samples taken in connection with these CBR tests

and undisturbed samples taken in cylinders and wooden boxes came from

depths of 24 to 34 in. because of the length of the samples.

Field In-Place, CBR, Moisture, and Density Test Data

43. The results of field in-place CBR tests and corresponding

water content and density determinations made on samples taken in

volumetric cylinders immediately adjacent to the point where the in-place

CBR test was performed are shown on figs. 13-19. The curves shown on

these figures illustrate the variation of field in-place CBR and density

with water content for three different depths. Moisture-density data

substantiate construction-lift data previously discussed, with the possible

exception that the optimum water content for the 450-psi sheepsfoot

30

roller section is approximately 12.5% instead of 11.5% and is therefore

more nearly·equal to the 250-psi sheepsfoot roller and tractor optimums

than the differences indicated by construction-lift data. Although no

20,000-lb wheel load, construction-lift data were previously shown, the

field in-place data for this wheel load shown on fig. 17 are in agreement

with the wobble-wheel and 40,000-lb wheel load data.

44. The field in-place CBR data shown on figs. 13-19 are tabulated

below: CBR at 12-In. Depth CBR at 24-In. Depth Max- Min- At Opt. Max- Min- At Opt.

Equipment imum imum w.c. imum imum w.c.

Tractor 13 3 6 14 3 4* 250-psi sheepsfoot 19 2 8 15 1 12 450-psi sheepsfoot 20 4 9 19 9 14 1500-lb wobble-wheel 18 6 6 18 1 8 20,000-lb wheel load 18 2 8 19 2 9 40,000-lb wheel load 22 2 6 22 2 6

(4 coverages) 40,000-lb wheel load 28 8 8 23 2 5

(8 coverages)

* 17-in. depth

It may be seen from the above tabulation that for the tractor and sheeps-

foot compaction there is an apparent increase in both the maximum CBR and

the CBR at optimum water content with increase in weight of compacting

equipment. The data for the rubber-tired rollers do not reflect any poai-

tive effect of increased compactive effort for the CBR at optimum water

content but do show a tendency for the maximum CBR to increase with in-

crease in compactive effort.

CBR, Moisture, and Density Data from Undisturbed Samples Taken in Cylinders

45. The results of CBR tests made on unso&ked and soaked samples

31

taken in CBR molds from the various unite are shown on figs. 20-26 •.

The moisture-density curves shown on these figures were obtained from

water content and density determinations made on the sample received in

each cylinder. It can be noted that these curves are not in exact agree­

ment with similar curves shown on figs. 13-19. This difference is prob­

ably due in part to the slight variations in density and water contents

existing in the fill. Data for curves on figs. 13-19 are from volumetric

samples taken immediately adjacent to field CBR tests, while data on figs.

20-26 are from undisturbed samples taken at another location in the

test pit. With the exception of the tractor section, the data for each

type of compaction equipment were obtained on samples taken at three

depths; samples in the tractor section were taken at only two depths.

46. Tho maximum density obtained in the cylinders from the tractor­

compacted sections was about 112 lb per cu ft, whereas the maximum den­

sity of the cylinder samples from the 250- and 450-psi sheepsfoot roller

sections was about 115 to 116 lb per cu ft, although the optimum water

content as determined by data from the cylinder samples was constant at

12% for all three pieces of equipment. In the case of the pneumatic­

tired equipment it appears that the wobble-wheel roller developed an

average maximum dry density of 116 lb per cu ft at an optimum water

content of about 12%, whereas the 20,000- and 40,000-lb wheel loads

had equal maximum densities of approximately 117 lb per cu ft at a

slightly lower optimum water content of approximately 11.5%.

47. As previously mentioned, it was intended originally to construct

test sections with a 750-psi sheepsfoot roller and an 8000-lb rubber-tired

wheel load. However, it was decided to abandon the 750-psi sheepsfoot

32

rol~er section, since examination of the field data revealed that the

250- and 450-psi sheepsfoot roller sections did not show any significant

differences in maximum density and optimum water content.

48. MUch the same reasoning was followed in eliminating the section

to be constructed using the 8000~lb rubber-tired wheel load. The first

section built with pneumatic-tired e~uip.ment was the wobble-wheel roller

section. As pointed out before, the wobble-wheel roller produced maximum

densities only slightly greater than those obtained with the sheepsfoot

rollers. Because of the trend of the sheepsfoot roller data and the fact

that the 20,000-lb wheel load rubber-tired e~uipment was being used else­

where, it was decided to construct the 40,000-lb wheel load section im­

mediately after the construction of the wobble-wheel roller section. The

40,000-lb wheel load e~uip.ment produced densities practically e~ual to or

only slightly greater than the wobble-wheel roller. In scheduling the

remainder of the construction it was therefore decided to abandon the

section to be constructed with the 8000-lb wheel load but to include the

20,000-lb wheel load in order to have a better spread of rubber-tired

wheel loads and to obtain a check on the wobble-wheel and the 40,000-lb

wheel load data.

49. The range of unsoaked CBR values at optimum water contents ob­

tained from tests made on cylinder samples showed no significant differ­

ences from values obtained by field in-place tests. This factor will be

more fully discussed in paragraphs 57 to 63.

50. One significant trend seems to stand out for all types of

e~uipment. This is for the case of the soaked CBR values, where it can

be noted by reference to figs. 20-26 that the material on the dry side

33

of optimum water content swelled sufficiently on soaking to cause pro­

nounced lowering of the CBR value over that obtained for the unsoaked

condition at the same as-compacted density and water content. It is

also important to note that for any given difference in water content

from optimum, the soaked dry-side CBR and the soaked wet-side CBR were

approximately equal, and that the maximum soaked CBR occurs at optimum

water content. Also, the soaked and unsoaked CBR values at optimum water

content are approximately equal.

51. The variations in CBR and density with water content for ma­

terial compacted in the laboratory and in the field are summarized on

fig. 27 for one depth at which samples were taken in the field. All the

data obtained from field in-place tests and from soaked and unsoaked CBR

tests on undisturbed samples from the 12-in. depth for all types of com­

paction equipment used are shown on this figure. A review of previous

figures shows no significant difference in density and CBR values for

samples taken at various depths. Therefore, for purposes of comparison,

the 12-in. depth was taken as being representative of all depths.

52. The curves shown on fig. 27 are the same curves shown on

figs. 13-26 for the 12-in. depth. Also shown on this figure are the

results of standard and modified AASHO laboratory compaction tests and

corresponding CBR-water content curves for material in the unsoaked con­

dition, together with the Porter 2000-psi static compaction data and CBR

curves in the unsoaked condition.

53. It appears from the data shown on fig. 27 that the compaction

characteristics of the tractor, sheepsfoot roller, wobble-wheel roller

and heavy rubber-tired rollers are very similar to those obtained by the

dynamic laboratory method of compaction. In general, the maximum dry

densities obtained in the field are equal to or slightly less than those

obtained by standard AASHO compaction and 6 to 10 lb less than obtained

by modified AASHO compaction. As previously shown by the construction­

lift, field in-place, and cylinder data in fig. 27, approximately 94 to

97% of modified AASHO compaction was obtained by the field equipment for

the number of passes used. The range of CBR values of field-compacted

material was also more nearly equal to those obtained from specimens

compacted by standard AASHO effort than by modified AASHO or Porter

2000-psi compaction.

54. The optimum water content, maximum dry density, and CBR for

dynamic and static laboratory compaction, and all of the data from field

test fills compacted with various types of equipment, are tabulated and

shown in table 1. This table was prepared by first listing the optimum

water content and density developed by standard and modified AASHO labora­

tory compactive effort and each piece of field compaction equipment. Two

values are shown for the field data because water content and density

values corresponding to field in-place CBR values were obtained from

density tests made adjacent to tho penetration test and similar data for

the undisturbed cylinder samples were determined directly from the sample

tested. The CBR values listed under the heading of "Field Compaction" are

actual field test values. The CBR values shown for laboratory dynamic and

static compaction in a 6-in. mold were obtained from figs. 2-5 for the

water content and density values listed in the figure. Data for the 7.4-

in.-and 12-in.-diam molds were taken from a letter report dated l

October 1945 to Office, Chief of Engineers,_ subject 11 Preliminary Results

35

of Tests to Study the Effect of Mold Size on CBR." This table permits

a direct comparison of CBR values of material compacted in the laboratory

and in ~he field at the same water contents and densities. It is impor­

tant to note that at optimum water content the CBR values for soaked

undisturbed samples are about equal to the unsoaked value except for the

250-psi sheepsfoot roller section.

55. As it has been general practice to specify that a certain

degree of compaction be obtained at modified AASHO optimum water content,

the densities and CBR values obtained in the field at this water content

are given in table 2. For the clayey sand used in this investigation,

the modified AASHO optimum water content is 10%. In the case of the data

for the field-compacted specimens, the data shown in tables 1 and 2 are

taken from fig~. 13-26 for the 12-in. depth. These data show that none

of the field equipment approached modified AASHO density at this water

content for the number of passes of equipment used. It further shows

that all field CBR values are more nearly equal to CBR values obtained

on dynamically compacted laboratory specimens than on statically

compacted specimens.

Results of Unconfined Compression Tests

56., The results of unconfined compression tests performed on 2-

by 4-in. specimens cut from the undisturbed test pit samples obtained

from various units are shown on figs. 28 and 29. These data are for

the clayey sand in the unsoaked condition. Tests were performed on

samples taken from three different depths in the test fills but there

was no significant difference in the dry densities obtained at the various

depths. Therefore, all teat points were plotted (water content vs dry

density and compressive strength) disregarding depth. This resulted in

a sufficient amount of reliable data to allow plotting of water content­

density curves and to establish a trend of variation of unconfined com­

pressive strength with water content. Points shown on figs. 28 and 29 are

averages of several points, which were arrived at by using the same pro­

cedure as was used in plotting the water content-density curves and the

variation of CBR with water content curves for the field-compacted fills.

Results of these tests are summarized on fig. 30. A comparison of un­

confined compressive strength of laboratory-compacted specimens with

field-compacted specimens is shown in table 3. It appears from the data

shown in this table that the field-compacted material has strength

characteristics very similar to those of dynamically compacted laboratory

specimens. This is also true in regard to the strain characteristics of

the material, as no appreciable differences in the stress-strain curves

were obtained from material compacted by dynamic effort in the laboratory

or by sheepsfoot rollers or rubber-tired rollers in the field.

37

PART VI : DISCUSSION OF CBR TESTS

57. In the letter report to the Chief of Engineers, dated 1 October

1945, subject "Preliminary Results of Teste to Study the Effect of M:>ld

Size on CBR", it was shown that CBR values decreased with increasing mold

size. Additional data obtained from the field teste reported herein

permit further conclusions regarding the effect of mold size on CBR values

and are discussed in the following paragraphs.

58. It is considered that variations in CBR values due to mold

size may be due to at least two causes: (1) the confining effect of the

mold during compaction of the specimen; and (2) the confining effect of

the mold during the penetration of the specimen. CBR values of the clayey

sand were obtained from three sources: namely,

a. Specimens compacted in molds in the laboratory and penetrated in molds.

b. Undisturbed field samples, compacted in the field by field equipment and penetrated in molds.

c. Field in-place tests, compacted in the field and penetrated in the field.

Thus, if CBR values from ~ and ~ are equal to each other and are higher .

than ~ it would appear that differences are due to the confining effect

of the mold during the penetration of the piston. On the other hand, if

b and c are equal to each other and are lower than ~ it would appear that

differences are due to the confining effect of the mold during compaction.

59. Table 4 presents the ratio of CBR values for field in-place,

mold, and laboratory tests. Data shown under "Optimum Water Content"

were computed from values given in table 1, and under "10% Water Content"

from table 2. Column (1) ~is the ratio of CBR values from laboratory

38

compacted and penetrated molds to values from field in-place tests. It

is apparent that the laboratory values are higher than the field in-place

values for all types of compaction equipment and that the values of the

ratios fall naturally into two groups consisting of the tractor-sheepsfoot

rollers and the pneumatic rollers. Similarly, it can be seen in column

(2) that laboratory-compacted values are appreciably higher than field­

mold values. It is not possible to get a ratio of field in-place values

to mold values directly, as the densities are not equal (tables 1 and 2).

However, an approximation can be obtained by simply dividing the ratios

in column (2) by those in column (1), as shown in column (3). The values

obtained are not absolutely correct, as the water contents are not con~

stant, but are sufficiently accurate for purposes of comparison. A

comparison of CBR curves on fig. 27 for field in-place and cylinder tests

shows that the computed ratios are approximately correct. Summarizing,

it appears that at the optimum water content for pneumatic rollers,

unsoaked CBR values from laboratory tests are about 2.1 times us great as

from field in-place tests and 2.9 times as great as from tests on un­

·disturbed mold samples. Also, the field in-place values are about 1.4

times as great as mold values. The same trend is evident for the tractor­

sheepsfoot datu but the differences are not as great.

60. The fact that CBR values from tests on undisturbed molds are

lower than values from field in-place tests cannot be definitely explained.

The method of obtaining the undisturbed mold samples has been explained

in paragraph 35 and illustrated by photographs 22 and 23. During sam­

pling, all confining effects of the surrounding soil are removed and the

sample is thus afforded an opportunity to expand or to rebound from the

39

constraining effect of the surrounding soil and to reach a state of equi­

librium with no confinement. Therefore, it' is probable that undisturbed

samples when tested in CBR molds actually have less confinement than soil

that is tested in place.

61. The data from soaked specimens in columns (4) and (8) show

much the same trend as pointed out for the unsoaked data at optimum

water content. The unsoaked data for 10% water content, which is dry of

optimum, are rather erratic. Note, however, that column (7) agrees with

column (3), in that field in-place CBR values are higher than values from

undisturbed molds.

62. Referring to paragraph 58, it is believed that the effect of

mold size on CBR values is due to a great extent to the confining effect

of the mold during compaction, as condition a is definitely greater than

conditions b and c. Positive conclusions <::annot be made concerning the

confining effect of the mold during penetration, due to the uncertainties

of the confinement of undisturbed samples penetrated in molds.

63. The foregoing discussion is not intended to establish any fixed

relationship between CBR values from field in-place tests and conventional

laboratory values, as sufficient data are not available for this purpose.

It is believed that sufficient data have been obtained to show, for this

particular soil, that field in-place values and laboratory values cannot

be used interchangeably, and that caution should be used with CBR values

from in-place tests for ever,y soil until some relationship has been def­

initely established. The results of unconfined compression tests show

that the strengths of material compacted in the laboratory and in the

field (table 3) are about equal. This fact tends to confirm the opinion

40

that the low field in-place CBR values are not a true measure of the

strength of the soil relative to the strengths shown by laboratory com­

paction tests.

64. Another char~cteristic of this clayey sand worthy of note is

that the soaked CBR value at low densities is practically independent of

water content, as can be seen by the curves in.the right hand plot of

fig. 3. Table 5 shows the CBR value at 1% dry of optimum, at optimum,

and 1% wet of optimum water content for all types of compacting equipment.

Thus, changes in water content near optimum are not critical for this

material, insofar as CBR values are concerned.

41

PART VII: SUMMARY AND CONCLUSIONS

65. Based on the data presented in this report, the following

summary and conclusions appear to be warranted for the clayey sand

studied:

a. Due to the highly plastic character of the material passing the 200-mesh screen (plasticity index= 45), the material exhibited compaction characteristics of a fine-grained material rather than a sand, as illustrated by the marked effect of moisture content.

b. The following maximum dry densities, expressed as a percentage of modified AASHO maximum density, were obtained:

No. of Height of Modified AASHO Eg_uipment Passes Lift - In. Densit;r in ~

34,000-lb tractor 3 6 91-92 250-psi sheepsfoot 9 6 94 450-psi sheepsfoot 9 6 93-95 15,000-lb wobble wheel 6 3 94-95 20,000-lb wheel load 4 6 95 40,000-lb wheel load 4 6 94-96 40,000-lb wheel load 8 6 95-97

It is noted that only a slight trend for increase in com­paction occurred with the use of heavier equipment. It is further noted that the rubber-tired equipment gave slightly higher densities than did the tractor or sheepsfoot rollers for the number of passes used. The sheepsfoot roller did not walk out with i~creasing number of pusses.

c. The optimum water contents, as developed by field equip­ment, were about equal to optimum water contents ob-tained by standard AASHO compaction as shown in the follow­ing tabulation:

Compactive Effort

Standard AASHO Tractor 250-pei sheepsfoot 450-pei eheepsfoot 15,000-lb wobble wheel 20,000-lb wheel load 40,000-lb wheel load

Optimum Water Content

11.5 12.0 12.0 12.2 11.7 11.5 11.5

42

d. The stress-strain curves from CBR testa of field-compacted material were much more similar to curves of laboratory, dynamically compacted material than to statically compacted material.

e. In general, CBR values of field-compacted material did not agree with CBR values from laboratory-compacted material but varied in a systematic manner (see table 4).

f. The maximum soaked CBR for field-compacted material occurred at field optimum water content and the curve is symmetrical about this point for a range of about 2% in water content.

TABLES

Table ~

SUMMARY OF OPl'IMUM WADR Ccm!ENT 1 DENSITI 1 AND C:BR FCB I.ABCmATaRY AND J'IEU) CCIIPACTIOH

ciil:if'ornia Beari.iii !!!t1o tc:aal Static fA})()ft: Opt1llium Per Cent Dynamic IA'borator.;-CO!!IJ!!:CtiiiiiK

Water Max:iJiium of Fie~d Compaction .4-in. 12-in. to:z Compaction& Content Dry Modif'ied Undisturbed 6-in. Diameter Diameter 6-in.

Type of Per Density AASBO In ~lind. Samples Diameter Mold )t)ld )t)ld Diameter Mold CQ~~~PaCtion Egu1J!!!!nt Cent" LbLCU Ft Densitz Place oakedsoiked Unsoaked Soaked Unsoaked Uii&oaked Unsoaked w Modif'ied AASBO 10.0 122.2 100 65 47 52 19

Standard AASll> 11.5 ll6.2 95 15 15 14 4

Static 2000 psi 13.0 114.3 94 17 19

34,500-lb tractor 13.5b m.ob ~ 6 9 7 3 3 17 18 (3 coverages) 12.0C 1ll.5c 91 7 5 11 9 6 3 20 8

2,o-pa1 aheepsfoot 12.7 115.3 94 8 11 11 8 25 21 (9 passes) 12.2 114.5 94 12 8 12 11 10 4 28 l.8

450-pai aheepsfoot 12.4 m.5 93 9 9 10 7 4 25 17 (9 passes) 12.3 115.5 95 7 8 12 10 8 4 29 20

1500-1b wobble-whee~ 12.2 115.3 94 6 12 12 8 4 29 20 (6 coverages) 11.6 ll6.o 95 5 6 16 15 13 4 35 20

20,000-~b whee~ load 12.2 116.0 95 8 15 14 7 4 31 21 (4 coverages) 11.3 116.5 95 8 9 20 l.8 14 5 38 20

40,000-lb wheel load 12.2 ll6.2 95 6 15 14 6 4 31 21 ( 4 coverages) 11.5 117.0 96 1 8 24 20 14 5 38 21

40,000-lb wheel load 12.0 116.0 95 8 15 15 8 4 32 21 ( 8 coverages) 11.3 118.0 rn 13 13 32 23 15 5 4o 23

Botes: a IAborator;r OBR "t'al.ues correepond.ing to water contents and densities obtained in the field. b Water contents and densities correapcnUng to in-place OBR determined by volumetric samples taken adJacent to

teat location (parasraph 35) • c Water contents and densities correapcmd1ns to C:BR values of un41aturbed cylinder samples on which CBR teat was perf~ (parasraph 36). . Field data are frclll. 12-in. depth.

Table 2

SUMMARY OF DENSITY AND CBR FOR LABORATORY AND FIELD COMPACTION AT MODIFIED AASHO OPI'IMIJM WATER CONTENT

DyDamic Laborat~ COlllpa.ction Field Compaction CBRb Static Lab.

Dry Per Cent CBR 7.4-in. 12-in. Compaction CBBb Density of Mod. CBR Undisturbed 6-in. Diameter Diameter 6-in.

Type of at l~a AAsRO In Cllind. Samples Diameter Mold Mold Mold Diameter Mold Co~ction Eguipment w.c. Densitz Place Unsoaked Soaked Unsoaked Soaked Unsoaked Unsoaked Unsoak.ed Soaked

34,500-lb tractor 107 .• 5c 88 12 11 6 8 (3 coverages) 107.5d 88 9 6 11 6 8

250-psi sheepsfoot 109.5 90 19 12 9 11 3 17 8 (9 passe"') 110.5 90 14 8 12 10 12 4 22 9

450-psi sheepsfoot 108.5 89 16 11 8 10 4 12 7 (9 passes) 112.5 92 16 14 8 14 13 16 4 37 12

1500-lb wobble-wheel 110.0 90 15 -- 12 10 12 4 22 9 (6 coverages) 111.0 91 7 4 12 11 14 4 30 10

201 000-lb wheel load 110.0 90 13 12 10 12 4 22 9 (4 coverages) 113.2 93 10 6 15 14 18 4 39 13

401 000-1b wheel load 112.5 92 14 14 13 16 4 37 12 (4 coverages) 113-5 93 10 5 15 15 18 5 40 l3

4o,OOO-lb wheel load 111.0 91 16 12 11 14 4 30 10 ( 8 coverages) 115.2 94 15 10 22 19 . 22 6 45 16

Notes: a Modified AASHO optimum water content. b CBR values corresponding to densities obtained in the field at 1~ W .c. c Densities corresponding to in-place CBR determined by volumetric samples taken adjacent to test location

d (paragraph 35).

Densities corresponding to CBR values of undisturbed samples determined from cylindrical sample on which CBR test was performed (paragraph 36).

Field data are from 12-in. depth.

Type of Compaction Equipment

34,500-lb tractor (3 coverages)

250-pei sheepsfoot (9 passes)

450-psi sheepsfoot (9 passes)

Opti­mum

w. c. ~

11.5

1500-lb wobble-wheel 12.0 (6 coverages)

20,000-lb wheel load 11.7 (4 coverages)

40,000-lb wheel load 12.4 (4 coverages)

40,000-lb wheel load 11.0 (8 coverages)

Table 3

SUMMARY OF UNCONFINED COMPRESSION TEST DATA

Maximum Dry

Density Lb/Cu Ft

111.0

m.o

115.0

117 ·5

118.2

116.9

117 .o

Unconfined Compressive Strength Lb per Sq In.

Field Laboratory Uneoaked Soaked Unsoaked Soaked

6.1

6.0

6.0 6.0

9.3 10.6

7·5 11.5 7·5

9·5

ll.O 11.0

Dry Density 1~ w.c. 108.2

110.5

ll2.0

ll5.0

113.3

115.0

Unconf'. Comp:t-"ss. Strength Lb per Sq In.

at 1~ W.C • .:. Uneoaked Field Laboratory

8.8 8.2

10.1 7·5

10.0

ll.O 8.8

12.8 10.3

NOTE: All unconfined compressive strength data for the field were obtained from specimens cut from 9-in. cubic box samples. All laboratory unconfined compressive strength data were obtained from dynamically-compacted specimens. All laboratory values correspond to densities obtained in the field at the field optimum water content, and to 10~ water content (modified AASHO optimum) at the density obtained in the field.

Table 4

RATIO OF CBR VALUES FROM FIELD IN-PlACE, )I)IJ), AND lABORATORY TESTS

At Field QRtimum Water Content At 1~ Water Contenta

Unsoa.k:ed Soaked Unsoa.k:ed Soaked La.b.'D Lab. F.I.P. Lab. Lab. Lab. F.I.P. Lab.

Compaction F.I.P. MOld Mold Mold F.I.P. iiOid Mold MOld E!iui;2ment ~ll (2} Pl ~ ~5l ___@ ~7l ...@l

34,500-lb tractor 1.5 1.6 1.1 1.8 0.9 1.2 1.3 1.0 (3 coverages)

250-psi sheepsfoot 1.4 1.0 0.7 1.4 0.6 0.9 1.5 1.3 (9 passes)

450-psi sheeps:f'oot 1.0 1.7 1.7 1.3 0.7 1.0 1.4 1.6 (9 passes)

AVERAGE 1.3 1.4 1.1 1.5 0.7 1.0 1.4 1.3

1500-lb wobble wheel 2.0 3.2 1.6 2.5 0.8 1.7 2.1 3.0 (6 coverages)

20,000-lb wheel load 1.9 2.5 1.3 2.0 0.9 1.5 1.7 2.3 ( 4 coverages)

40,000-lb wheel load 2.5 3.4 1.4 2.5 1.0 1.5 1.5 3.0 ( 4 coverages)

40,000-lb wheel load 1.9 2.5 1.3 1.8 0.8 1.5 1.9 1.9 (8 coverages)

AVERAGE 2.1 2.9 1.4 2.2 0.9 1.6 1.8 2.5

Notes: a Modified AASBO optimum water content.

b Abbreviations in column headings have following meanings:

Lab. - Conventional laboratory CBR test in 6-in.-diam mold.

F.I.P. - Field in-place CBR test.

Mold - CBR tests QD. undisturbed samples taken in cylindrical :molds.

Table 5

CBR VALUES AT WATER CONTENTS DRY AND WET OF OPTIMUM

Compaction 3-in. Depth J2-in. Depth 24-in. Depth Equipment 1% Dry Optimum l% Wet l% Dry Optimum lop Wet lrfo Dry Optimum ltfr, Wet

250-psi sheepsfoot 7.0 8.0 8.0 8.5 8.0 7.0 8.0 10.0 10.0 (9 passes)

450-psi sheepsfoot 9.0 8.0 5.0 4.0 3.0 (9 passes)

1500-lb wobble-wheel 4.0 4.0 4.0 5.0 6.0 7.0 3.5 4.0 5.0 (6 coverages)

20,000-lb wheel load 5-5 6.0 5.0 6.5 9.0 6.5 8.0 10.0 8.0 (4 coverages)

40,000-lb wheel load 6.0 6.0 6.0 8.0 6.0 7.0 7.0 6.0 (4 coverages)

40,000-lb wheel load 10.0 lO.O 6.0 11.0 13.0 9.0 ]2.0 ll.O 7.0 (8 coverages)

34·, 500-lb tractor 2.0 3.0 (3 coverages)

4.0 6.5 5.5 3.0

Note: CBR values obtained from tests made on undisturbed samples.

PHOTOGRAPHS

Killifer plow and Seaman pulvimixer plowing material prior to compaction

-c ::c 0 -; 0 G> :::0 )>

-c :r: N

450-pei eheepefoot roller, first pa.ee, 6'1> water content

450-pei eheepefoot roller, first paee, 7-1/2~ water content

450-pei eheepsfoot roller, first pass, 9~ water content

450-pel sheepsfoot roller, first pass, 10-l/2~ water content

450-psi sheepsfoot roller, first pass, 12i water content

450-pei eheepefoot roller, ninth paee, 6% water content

450-pai sheepsfoot roller, ninth pass, 7-1/2~ water content

450-psi sheepsfoot roller, ninth pass, 9% water content

450-psi sheepsfoot roller, ninth pass, 10-1/2~ water content

"'0 :::r: 0 -f 0 G)

::0 )>

"'0 :::r:

450-pei eheepefoot roller, ninth pass, 12~ water content

40,000-lb wheel load, first coverage, 6% water content

40, 000- lb wheel l oad, first coverage , 8% water content

40, 000-lb wheel load, first coverage, 10~ water content

40, 000-lb wheel load, first coverage, 12% water content

40,000- lb wheel load, first coverage, 14~ water content

40,000-lb wheel load, fourth coverage, 6~ water content

00

40,000-lb wheel load, fourth coverage, 8% water content

40, 000-lb wheel load, fourth coverage, 10% water content

40,000-lb wheel load, fourth coverage, ~ water content

40,000-lb wheel load, fourth coverage, 14~ water content

Steps in obtaining undisturbed box samples in test pit

Steps in obtainine undisturbed cylinder samples in teet pit

PHOTOGRAPH 23

,

Steps in obtaining undisturbed cylinder samples in test pit

PHOTOGRAPH 24

FIGURES

., G1 c ::0 fT1

100

90

80

70

-.c 160 ~ a; c 50

LA: -c 4> :.l40 ...

Q..

30

20

10

Tyler Sieve Openinp in Inches Tyler Standard Sieve Numbers 3 2 15 105 074 053 037 3 4 6 8 10 14 20 28 35 48 65 100 150 200 I I I' I I I

r-.~ I I I I

['\

'\ L.L. PL. 'f.. I. S.G. ' 18 16 2. 8

\ M• T£1 IAL P I_CI~ /~( \

200 MESH t.t v.=-L.L. P.L. 'f.. I. 74 29 ~5

~

' 50 10 5 0.5 0.1 0.05 0.01 0.005 0.001

Grain Size in Millimeters

Large Gravel Medium Gravel · Silt Clay

CLASSifiCATION DATA FOR CLAYEY SAND

.., Ci c :XJ 1"'1

N

.... 1~0

12~

1-z ~ 100 a: Ill IL

!

"' 7!1

Ill u 0 Ill ~

~ a: a: 0 2!1 u

0

12!1

t: 120 ::> u a: Ill

liS IL

~ Ill ..J

! 110 ,.. !:: ~ z

10!1 Ill Q ,.. "' Q

100

10 IS 20

DYNAMIC COMPACTION IN 6-INCH-DIAMETER MOLD

325~~~~~~~~crii!JJ;~~~~~~~~ FIGURE BESIDE CURVE IS MOLDING WATER CONTENT

300

27S

22S

1-~200 u

"' Ill IL

! 17!1

~ u Q 1!:>0 Ill

t Ill

"' "'12!:> 0 u

100

75

50

25

130

ushPII~~~~~~~~~~DC~~ FIGURE BESIDE CURVE IS MOLDED DRY DENSITY

275

250

1-

~200 u «· Ill IL

! 175

"' Ill u Q 150 Ill

t Ill

~125 8

100

75

50

l!Q!L POINTS SHOWN OBTAINED BY IPITERI'OLATION

FROM DENSITY VS CBR Pl.OT.

O 5 6 7 8 9 10 II 12 WATER CONTENT IN PERCENT DRY WEIGHT

MOLDING WATER CONTENT VS DENSITY AND CBR

100 lOS 110 115 120 125 MOLDED DRY DENSITY IN LBS PER CU FT

DENSITY VS CBR MOLDING WATER CONTENT IN PERCENT DRY WEIGHT

WATER CONTENT VS CBR

o--­o------

LEGEND SLOWS PER WEIGHT

~ ...L..A:a.B. ..I:IAYJiW!. !I 5 5 5 3

100 !Ill 26 12 12

IOL8S IOLI!S IOL8S IOL8S S.!:>LBS

DROP IN INCHES

18 Ill (MOD. AASHO) 18 18* 12

NOTES: SPI!:C.IIAEPIS TESTED AS MOLDED (U NSOAKED).

PI!:NETRATIDN SURCHARGE IOLBS.

* E:QUIV. TO STD. AASHO E:F"FORT

CBR, DENSITY AND WATER CONTENT DATA DYNAMIC COMPACTION, AS MOLDED

.. .. . ~ ~ -· -

DYNAMIC COMPACTION IN 6-INCH-DIAMETER MOLD •~o 130 130

FIGURE BESIDE CURVE IS MOLDINCO WATER CONTENT FIGURE BESIDE CURVE IS MOLDED DRY DENSITY

125 120 120

1-z ::l 100 110 110 "' Ill .... !

"' 75 100 100

ID ~ u POINTS. SHOWN OBTAINED BY INTER POLATIOI'( 0 F"ROM DENSI TV VS CBR PLOT. Ill 50 eo 110 t; Ill

"' "' 1- 1-0 25 ~eo z eo u Ill

u u

"' "' Ill Ill .... .... 0 ! 70 ! 70

"' "' ID ID u u

124 0 60 0 60 Ill ... t; t;

1- ... "' IL 120 "' 50 ~50 "' :;) 0 s u u

"' ... 40 .... 116 40

on ID ...1 . ! 110 30 30 > !:: on z

105 20 ... 20 0

> "' 0

100 10 10

1155 10 I !I 20 011!1 100 10~ 110 11!1 120 12!1 130 06 7 a g 10 II 12 13 WATER CONTENT IN PERCENT DRY WEIGHT MOLDED DRY DENSITY IN LBS PER CU FT MOLDING -TER CONTENT IN PERCENT DRY WEIGHT

MOLDING WATER CONTENT VS DENSITY AND CBR DENSITY VS CBR WATER CONTENT VS C8R !..~~~NO

IILOWS PER W!:IGHT DROP IN NOTES: SPECIMENS SOAKED I'ROM TOP !,.AYERS ~ ~ INCHES o--- !I 100 .10 LIIS 18 AND BOTTOM .

o--- !I !1!1 10 LIIS IIICMOO. MSHQ) SOAKING AND PENETRATION CBR. DENSITY AND WATER CONTENT DATA, - 5 26 lOLilS Ill SURCHARGE IDLBS. .,...___..._ !I 12 10 Lilli 1a• DYNAMIC COMPACTION. SOAKED - 3 12 5.!1LIIS 12 i1< EQUIV. TO STD. AASHO EI'I'ORT

...., G) c ;o ,...,

~ 1-z .. u a: .. .. ~ a: II u 0 .. 1:) .. a: a: 0 u

1-.. ~ u a: .. .. ., II ...J

~ > !::: ., z .. 0

> a: 0

STATIC COMPACTION IN 6-INCH-DIAMETER MOLD 150

FIGURE BESIDE CURVE IS MOLDIN,; WATER CONTENT FIGURE BESIDE CURVE IS MOLDED DRY DENSITY

125

100

75

50

25

0

130

120

110

300

275

250

1-

~200 u a: .. .. ~ 17!1

a: II u o ISO .. 1:) .. ~ 12!1 0 u

100

7$

50

2

100 0 0 5 10 15 100

WATER CONTENT IN PERCENT DRY WEIGHT

MOLDING WATER CONTENT VS DENSITY AND CBR

LEGEND

110 120 130 MOLDED DRY DENSITY IN LBS PER CU FT

DENSITY VS CBR

o--- 4000 PSI

D--- 2000 PSI

- IOOOPSI

NOTES: SPECIMENS TESTED M> MOLDED (UNSOAKED)

PENETRATION SURCHARGE 10 LBS.

STATIC. LOAD APPLIED F"RO!ol ONE END ONLY.

o ISO .. t .. a: a: 125

8

100

75

50

25

0

1!Q!L POINTS SHOWN OIJI"AINED BY INTERPOLATION

FROM DENSITY VS CBR PLOT .

6 7 II 8 10 II 12 13 MOLDING WATER CONTENT IN PERCENT DRY WEIGHT

WATER CONTENT VS CBR

CBR, DENSITY AND WATER CONTENT DATA STATIC COMPACTION , AS MOLDED

... z ... .... a:: ... G.

~ a:: Gl .... 0 ... ... .... ... a:: a:: 0 ....

! >­... iii z

&0

50

40

30

20

10

0

130

STATIC COMPACTION IN 6-INCH-DIAMETER MOLD

&0

5!1

!10

45

... ~ 40 .... a:: ~ ~ 35

a:: Gl .... o30 ... t ... a:: 0::25 0 ....

20

I !I

FIGURE BESIDE CURVE IS MOLDING WATER CONTENT

!10

... z40

~ r ~35

II: Ill .... o30

t ... a:: 11:25

8

20

Ill

FIGURE BESIDE CURVE IS MOLDED DRY DENSITY

~ POINTS SHOWN OBTAINED BY INTERPOLATION

F'ROM DENSITY VS CBR PLOT .

Ill

115

... 110 10 10 0

>-a:: 0

!I

~ 0 0 5 10 15 100

WATER CONTENT IN PERCENT DRY WEIGHT

MOLDING WATER CONTENT VS DENSITY AND CBR

LEGEND

110 120 130 MOLDED DRY DENSITY IN LBS PER CU FT

DENSITY VS CBR

o--- 4000 PSI

IJo-- 2000 PSI

- 1000 Pill

NOTES: SPECIMENS SOAKED FROM TOP AND BOTTOM.

SOAKING AND PENETRATION SURCHARGE 10 LBS

STATIC LOAD APPLIED I'ROM f:ACH END 01' SAMPLE.

II

0 II 7 II 8 10 II 12 13 MOLDING WATER CONTENT IN PERCENT DRY WEIGHT

WATER CONTENT VS CBR

CBR. DENSITY AND WATER CONTENT DATA , STATIC COMPACTION. SOAKED

...., C) c ::0 , 0)

eo ... > iii "' 50 ... a:: II. ::E....: Ofli 40 Ua;

oz w-z k:'l: 30 Zto-01-' uz zw :Ill:

20 .... ., :::!

~ >< 10

~

0

12!1

.... ... :I u a:: ... II. 120

"' • ..J

! )-

!::

"' z 115 Ill

0

)-a:: 0

5 10 15 20 WATER CONTENT IN PERCENT DAY WEIGHT

DYNAMIC COMPACTION

FIGURE BESIDE CURVE IS MOLDING WATER CONTENT

eo

110

10

0 110 115 120 125

iii 50 a: z

... > :1 35

I 8 30

~ ~ 25 0 u z :I

10

0

FIGURE BESIDE CURVE IS MOLDEO DAY DENSITY

l!!ru;. POINTS SHOWN OBTAINED BY INTERPOLATION

FROM DENSITY VS COMPRESSIVE STRENGTH PLDT.

I 7 8 II 10 II 12 13 MOLDING -TEA CONTENT IN PERCENT DRY WEIGHT

MOLDING W.C. VS DENSITY AND COMP STRENGTH MOLDED DRY DENSITY IN LBS PEA CU FT

DENSITY VS COMPRESSIVE STRENGTH WATER CONTENT VS COMPRESSIVE STRENGTH

LEGEND BlOWS

PER ~ ~

o-- $ 58 o-- $ 27 A-- 5 13

WEIGHT DROPIN ~ INCHt.S

5.5 12 5.5 12 !1.5 12

NOTE$: SP~C.IIoU:NS C.OMPAC.TED IN 3..Cl-INCH-DIAMETER MOLD.

TESTED A5 MOLDED (UNSOAKED). VARIATION OF UNCONFINED COMPRESSIVE STRENGTH WITH DENSITY AND WATER CONTENT

,~,~, «>'

I 40'

I 4q I 40' llO'i 120'1 ~· 40'

I 40'

I 40'

I 40'l01

/ I

~~ /' ~ I I I

~ ...L.J1/i.&. ~ ~ ~ ~ ~ ~ ~

SECTION 6

0: SECTION 2 WOBBLE-WHEEL ROLLER

~ ~ ~ § ~ ~ 450-PSI SHEEPSFOOT ROLLER .J ~ ::> SECTION 3 0

~ :I: 250-F'St SHEEPSrOOT ROLLER

SECTION 9

"' I!!) fill ~ li!l gii] ~ I ON/0 0: 1£1 1!§1 (!!! ~ [i] ...!..!!!L!!J.. 40.()00·LB WHEEL LOAD. SAME

"' NO. CF COIIERAGES AS SEC. BON 0 l1iZI ~ !i4l ~ 5§1 ONE SIDE AND OOUBLE THIS

~ .J

I ::> NO. ON THE OTHER SlOE. I

~ 0 SECTION 8 :I: ~ ~ ~ ·IS!! ~

®= "' 20,00D·LB WHEEL LOAD.

I "'j I [§

PLAN <6-PLAN

50' 40' ~I I 1 ..

NOTE:

NUMBERS IN SQUARES INDICATE TEST

QT SEC.2 \ SEC.J ~ PIT AND UNIT NUMBERS.

-J ~5' -H-s• I JO',I, J()',,. 40' I Jq,l SECTION A-A L~ SEco\sEcs~

AREA I -l~s·~~ SECTION C-C

,~1~1,4~,1 ~·l4o·. I ~·

1~1 ABEA 4

SHOULDER / I OM J ' [t~ [!] ~ ~ ~ 1m

r !..!!! SECTION 5

j_~~ I I 34,500-LB TRACTOR

....... I ON J t / ION5~10N5

SHOULDER ®- I -1 2'

"' PLAN SECTION B-B

AREA 3 LAYOUT OF TEST AREAS

120

115

110

1- 105 LL..

~ u a: 100 w m tl.

(f)

ID _J

110 z

>-1-(f) 105 z w 0

>- 100 a: __ 0 115

110

105

100

FIGURE 8

SAMPLES TAKEN AFTER CONSTRUCTION OF LIFT 4

I"

5

j) ....

/ .... , .....:n ' /

/

' v

v /

~ r-.l_

v, 1'.. / 1\.

I'¥ ~

c ~

v .... v

"' ;.. :l ./ ' / -...

/ /

/ t1

hoo 10 15 20 WATER CONTENT IN PERCENT DRY WEIGHT

0

0

TYPICAL MOISTURE-DENSITY DATA FROM CONSTRUCTION LIFTS

SECTION 5 - 34,500-LB TRACTOR- 3 COVERAGES

LifT 3 DEPTH 6''

LIFT 2 DEPTH 12~'

LIFT I DEPTH 18''

120

115

110

1-...... 105 ::> u

a: 100 w

ll. 115

U) 10 ...J

z 110 ->-1--U) 105 z w 0

>- 100 a: 0 115

110

105

100

SAMPLES TAKEN AFTER CONSTRUCTION OF' Ll F'T 6

1-......

"""' p.

t;1

J ,. ~

'f"' 1..;'

I-' ~

b ~ ~"'-m

r ....

Lf 1/

1.1 ~I;'

v

""' 1--"t--

h

~

tr v

7 v

/'J

5 10 15 20 WATER CONTENT IN PERCENT DRY WEIGHT

TYPICAL MOISTURE-DENSITY DATA FROM CONSTRUCTION LIFTS

SECTION 3- 250-PSI SHEEPSFOOT ROLLER -9 PASSES

LIFT 5 DEPTH 6 11

LIFT 4 DEPTH 12''

LIFT 3 DEPTH 18''

FIGURE 9

120

I 15

110

1-~ 105 ::> u a:

100 w a. I 15 (/) co ...1

z 110

>-1-(/) 105 z w 0

>- 100 a: 0 115

110

105

100

FIGURE 10

SAMPLES TAKEN AFTER CONSTRUCTION OF LIFT 6

, ' l

;:J

/ " j..

(

/ (t/

:) .... I .

~

)'-lj

/

/

/ 1: '

'S 0 I/

II

I

/t)

I

1/

If

50 10 15 20 0 WATER CONTENT IN PERCENT DRY WEIGHT

TYPICAL MOISTURE-DENSITY DATA FROM CONSTRUCTION LIFTS

SECTION 2 -450-PSI SHEEPSFOaT ROLLER-9 PASSES

LIFT 5 DEPTH 6 11

LIFT 4 DEPTH 12''

LIFT 3 DEPTH 1811

rr5

110

ro5

~ ~

roo 3 120

a: w Q.

115 Cl)

10 .J

z 110 ->-~

Cl) 105 z 120 w 0

>-a: 115 0

110

105

roo

SAMPLES TAKEN AF'TER CONSTRUCTION OF L1 FT 7

p ~ , , ' /

~ ~

~

:) , /

}

1/ ..... ~ 1/ .Cl

1/ /

t)l' ~

~

ru

':\ol

L /

~ \,

~ I"

/ J)

, ¥

5 10 15 20 WATER CONTENT IN PERCENT DRY WEIGHT

TYPICAL MOISTURE-DENSITY DATA FROM CONSTRUCTION LIFTS

LrrT 6 DEPTH 3''

L I F'T 5 DEPTH 6''

LIF'T 4 DEPTH 9 11

SECTION 6- !,500-LB WOBBLE -WHEEL LOAD- 6 COVERAGES

FIGURE II

120

115

110

t 105

::::> 120 u a: w 115 ll..

(/) m _J

z 110

>-1- 105 (/)-z 120 w 0

>-a: 115 0

110

105

100

SAMPLES TAKEN AFTER CONSTRUCTION OF LIFT 5

v ...... - CDI 't:fd~

"" / ~~ I ·,

',(

~

\.

~---- 8 c ov. E"H4 G.~. ... ~ "(~

v if'!'-. ~---'r-4 cc Ill E". ~- IGES 1/ ..&.

/ l<.l' '-v I'

1/ 1.. , /

11'1 ~ 1-~--" 8 iOII ~f?, IG ~p

v~ 1/ \

I 4 c: rc v. ~.-~ IG~ 1"'1 ~

v \ / ~ "' \

~ 1/ r'l \

/

/ II

lS I

......

5 10 15 20

WATER CONTENT IN PERCENT DRY WEIGHT

TYPICAL MOISTURE-DENSITY DATA FROM CONSTRUCT ION LIFTS

LIFT 4 DEPTH 6''

LIFT 3 DEPTH 12"

LIFT 2 DEPTH 18"

SECTION 9-40 7000-LB WHEEL LOAD -4 AND 8 COVERAGES

FIGURE 12

...... (;) c ::0 1"'1

w

1-z "' u a: "' a. ~

a: 01 u

0

"' 1-u "' a: a: 0 u

50

40

30

20

10

0

DEPTH 3"

>­z "' u a:

"' a.

~ a:

50

40

30

20

10

125

mtmmt~mm

~ 115 ., ., .J

~ 110

,.. >-

~ 105

"' 0

,.. :5 100

95 5 10 15

::: 120

:> u a: ~ 115

"' ., .J

~ 110 ,.. t II)

z 105

"' 0

,.. a: 0 100

20

DEPTH 12"

1- 50 z "' <.) a: ~ 40

~ a: "' 30 u

0

"' >-u 20

"' a: a: 0 u

10

0

~ 115

"' "' .J

~ 110

,.. ':: ~ 105

"' 0

,.. a: 0 100

DEPTH 17"

5 10 15 20 WATER CONTENT IN PERCENT DRY WEICHT WATER CONTENT IN PERCENT DRY WEICHT WATER CONTENT IN PERCENT DRY WEICHT

NOTES; WATER CONTENT VALUES USED IN CBR VS WATER CONTENT PLOTS WERE OBTAINED FROM DISTURBED SAMPLES TAKEN IMMEDIATELY BENEATH CBR PENETRATION PISTON.

WATER CONTENT AND DENSITY VALUES USED IN WATER CONTENT VS DENSITY PLOTS WERE OBTAINED FROM UNDISTURBED VOLUMETRIC SAMPLES TAKEN IMMEDIATELY AD~ACENT TO CBR TEST

VARIATION OF FIELD IN-PLACE CBR AND DENSITY WITH WATER CONTENT

SECTION 5-34,500-LB TRACTOR-3 COVERAGES

DEPTH 3" DEPTH 12 II DEPTH 24" 60 60 60

~0 ~0 50 ....

!Z !Z z "' u "' "' a: u u

40 a: 40 a: 40 II! "' w

a. a. ~ !: ~ a:

30 a: 30 a: 30 10 u 10 10 u u 0 0

"' 0 .... "' "' u 20 .... 20 tJ 20

"' u "' a: a: "' a: a: a:

0 0 a: u u 0

10 10 u 10

0 0 0 '

12!> 125 125

120 120 120

.... ... .... ... t-::> 115 115 ... 115 u ::> ::> a: u u

"' a: a: a. "' w 110 a. 110 a. 110 .,

10 "' :3 .J 10 .J .J

!: 105 !: 105 ~ 105 >- >- >-.... t- t: iii iii "' z z z "' 100 w 100 w 100 0 0 0

9!> 95 5 10 15 20 ~ 10 15 20

95 5 10 15 20

WATER CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT

NOTES: WATER CONTENT VALUES USED IN CBR VS WATER CONTENT PLQlS WERE OBTAINED fROM DISTURIIED SAMPLES TAKEN IMMEDIATELY 8ENEATH CBR PENETRATION PISTON.

VARIATION fiELD IN-PLACE CBR AND WATER CONTENT AND DENSITY VALUES USED IN WATER CONTENT VS OF DENSITY PLOTS WERE OBTAINED FROM UNDISTURBED VOLUMETRIC DENSITY WITH WATER CONTENT SAMPLES TAKEN IMMEDIATELY AD..JACENT TO C8R TEST.

SECTION 3- 250-PSI SHEEPSFOOT ROLLER- 9 PASSES

...., C) c .::0 ,., (]I

60

50 ,... z w u cr 40 w 0..

~ a: 30 ID u 0 w ,... u 20 w a: a: 0 u 10

0

125

,... 120 ...

:::> u cr w 0..

115

U)

Ill -'

~ 110

>-1-iii z 105 w 0

>-a: 0 100

95

NOTES:

DEPTH 3" 60

50

,... z w u 40 a: w 0..

~ a: 30 ID u 0 w ,... 20 u w a: a: 0 u 10

0

125

,... 120 ... ::> u a: 115 w 0..

en Ill -' 110 ~ >-1-iii 105 z w 0

>-a: 0 100

95 5 10 15 20 5

WATER CONTENT IN PERCENT DRY WEIGHT WATER

WATER CONTENT VALUES USED IN CBR VS WATER CONTENT PLOTS WERE OBTAINED FROM DISTURBED SAMPLES TAKEN IMMEDIATELY BENEATH CIIR PENETRATION PISTON.

WATER CONTENT AND DENSITY VALUES USED IN WATER CONTENT VS DENSITY PLOTS WERE OIITAINED FROM UNDISTURBED VOLUMETRIC SAMPLES TAKEN IMMEDIATELY ADJACENT TO CIIR TEST.

DEPTH 12" DEPTH 24 11

60

50 ,... z w u a: w 40 0..

~ cr 30 ID u 0 w ,... u 20 w a: a: 0 u

10

0

125

,... 120 ....

:::> u a: w 115 0..

en !D -' ~ 110

,_ ,... iii z 105 w 0

>-a: 0 100

95 10 15 20 5 10 15 20

CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT

VARIATION OF FIELD IN-PLACE CBR AND DENSITY WITH WATER CONTENT

SECTION 2- 450-PSI SHEEPSFOOT ROLLER- 9 PASSES

"T1 C) c ::0 ,..,

... z w 1.)

!>0

~ 40 n.

~

a: Ill 1.)

0 w ... 1.) w a: a: 0 1.)

30

20

10

0

t 120

:> 1.)

a: w Q.

"' Ill ...J

115

110 ~

>­... iii 10!> z w 0 ,.. g 100

DEPTH 3"

... z w 1.) a: 40 w n.

~ a: 30 Ill 1.)

0 w t; 20 w a: a: 0 1.) 10

0

... 120 "-:> 1.)

f5 115 0.

"' Ill ...J

~

>­...

110

iii 10!> z w 0

>-:5 100

10 I!> 20

... z

~ 40 w 0.

~ a: Ill 1.)

0 w t; w a: a: 0 1.)

30

10

0

... 120 "-:> 1.)

5 115 Q.

"' Ill ...J

110 ~

>­... ~ 10!> w Cl

,.. g 100

9!> !> 10 I!> 20

95~~~5~~~~~~10~~~~~~15~~~~~~2~0

WATER CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT

NOTES: WATER CONTENT VALUES USED IN CBR liS WATER CONTENT PLOTS WERE OBTAINED FROM DISTURBED SAMPLES TAKEN IMMEDIATELY BENEATH CBR PENETRATION PISTON.

WATER CONTENT AND DENSITY VALUES USED IN WATER CONTENT VS DENSITY PLOTS WERE OBTAINED FROM UNDISTURBED VOLUMETRIC SAMPLES TAKEN IMMEDIATELY ADJACENT TO CBR TEST

VARIATION OF FIELD IN-PLACE CBR AND DENSITY WITH WATER CONTENT

SECTION 6- 1,500-LB WOBBLE-WHEEL LOAD-6 COVERAGES

., C) c ;:o M

60

50 1-z w u IX w 40 Q.

~ IX 30 m u 0 w 1- 20 u w IX a: 0 u

10

0

125

1- 120 .... :> u a: 115 w Q.

Ill ., ..J 110 ~ > 1:: Ill 105 z ~ >-a: 100 0

95

NOTES:

DEPTH 3" 60

50 1-z w u IX 40 UJ Q_

3: IX 30 m u 0 w t- 20 u w IX a: 0 u 10

0

125

1- 120 .... :> u IX 115 w Q.

II) ., ..J

110 ~ >-t-in 105 z w 0

> IX 100 0

5 10 15 95

20 5 WATER CONTENT IN PERCENT DRY WEIGHT WATER

WATER CONTENT VALUES USED IN CBR VS WATER CONTENT PLOTS WERE OBTAINED FRO"' DISTURBED SA ... PLES TAKEN I"'"'EDIATELY BENEATH CBR PENETRATION PISTON.

WATER CONTENT AND DENSITY VALUES USED IN WATER CONTENT vs DENSITY PLOTS WERE OBTAINED FRO"' UNDISTURBED VOLU ... ETRIC SA ... PLES TAKEN I"'"'EDIATELV ADJACENT TO CBR TEST.

DEPTH 12" DEPTH 24" 60

50 t-z UJ u IX UJ Q_

40

~ IX

30 Ill u 0 w t- 20 u UJ a: IX 0 u

10·

0

125

1- 120 .... :> u IX 115 w Q_

Ill Ill ..J 110 ~

>-t: II) 105 z UJ 0

>-IX 100 0

95 10 15 20 5 10 15 20

CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT

VARIATION OF FIELD IN-PLACE CBR AND DENSITY WITH WATER CONTENT

SECTION 8-20,000-LB WHEEL LOAD-4 COVERAGES

DEPTH 3" DEPTH 12" DEPTH 24" &0 60 60

~0 1-~0

1-~

1-z z z "' "' "' u u u

"' a: a:

"' 40 "' 40 "' 40 Q. Q. Q.

~ ~ ~

a: a: a: Cll 30 Cll 30 Cll 30 u u u 0 0 0 ... ... ... 1- 1-

20 1-

20 u 20 u u "' ... "' "' a: a: a: a: a: 0 0 0 u u u

10 10 10

0 0 0

125 125 125

1- 120 1- 120 120 ... 1-::>

... IL

u ::> ::> u u "' a: a: "' liS 115 115 Q. ... "' Q. Q.

"' "' "' 10 .J 10 Cll

.J .J

~ 110 "!: 110

"!: 110

>- >- >-1- t: 1-iii

"' iii z lOS z 105 z 105

"' ... ... 0 0 0

>- >- >-

"' a: a: 0 100 0 100 0 100

95 5 10 15

95 20 5 10 15 20

95 5 10 15 20

WATER CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT

NOTES: WATER CONTENT VALUES USED IN CBR VS WATER CONTENT PLOTS WERE OBTAINED FROM DISTURBED SAMPLES TAKEN IMMEDIATELY BENEATH CBR PENETRATION PISTON.

WATER CONTENT AND DENSITY VALUES USED IN WATER CONTENT VS VARIATION OF FIELD IN-PLACE CBR AND DENSITY PLOTS WERE OBTAINED FROM UNDISTURBED VOLUMETRIC DENSITY WITH WATER CONTENT SAMPLES TAKEN IMMEDIATELY ADJACENT TO CBR TEST.

SECTION 9-40,000-LB WHEEL LOAD-4 COVERAGES

DEPTH 3" DEPTH 12" DEPTH 24" 60 60 110

50 .... 50 50 .... z .... z w z w u w u a: u a: w a: w 40 0. 40 w 40 0. 0.

!: !: !: a: a: a: en 30 en 30 en 30 u u u 0 0 a w w w .... .... 1-u 20 u 20 u 20 w w w a: a: a: a: a: a: 0 0 0 u u u

10 10 10

0 0 0

125 125 125

1- 120 t 120 .... 120 ' ... ...

::> ::> ::> u u u a: a: a: w w 115 0. 115 w 115 0. 0. ., "' "' en en ..J en ..J ..J

! 110 !: 110 !:

110

,.. ,.. !::

,.. .... 1-in en iii z 105 z 105 z 105

"' w w a a a ,.. ,.. ,..

a: a: a: 0 100 a 100 a 100

85 5 10 15 20

95 5 10 15 20

95 5 10 15 20

WATER CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT ORY WEIGHT

NOTES: WATER CONTENT VALUES USED IN CBR VS WATER CONTENT PI..OTS WERE OBTAINED FROM DISTURBED SAMPLES TAKEN IMMEDIATELY BENEATH CBR PENETRATION PISTON.

WATER CONTENT AND DENSITY VALUES USED IN WATER CONTENT vs VARIATION OF FIELD IN-PLACE CBR AND DENSITY PI..OTS WERE OBTAINED FROM UNDISTURBED VOLUMETRIC DENSITY WITH WATER CONTENT SAMPLES TAKEN IMMEDIATELY AO.JACENT TO CBR TEST.

SECTION 9-40,000-LB WHEEL LOA0-8 COVERAGES

., C) c ::0 1""1

1\) 0

t-a z"' w"' u• a:O w"' 11.

~ a: Ill u 0 ... t-a uw "'"' 0:< a:o Olll uz

t­... :> u a: w 11.

"' Ill ...1

z

:>

20

10

0

20

10

0

125

120

II!!>

110

>­!: "' 105 z ... a >-a: 100 a

20 a t-W Z"' w< uo O:lll 10 w a.

~ a: 0

uw

"'"' a:< a:O a"' u~ 10

DEPTH 12"

a t-w Z.:

20

W< uo ~(/') 10 a.

~ a: 0 Ill u 0

~e 20

"'"' a:< a:O O"' u; 10

0 0

t- 120 t- 120

DEPTH 17"

... ...

:> :> ~il~8EEEilll338EEiil33~~ii~~Effi~ u u ~ w ... a. a.

~ ~

~ ~ >­t-<ii 105 z w a >-~ 100

>-~ 105 z w 0 ,.. ~ 100

~ DATA AT THIS DEPTH NOT OBTAINED.

95~~~5~~~~~~10~~~~W-~1~5~~W-~~20. 95 5 10 15 20

95 5 10 15 20

WATER CONTENT IN PERCENT DRY WEIGHT

NOTE: ALL WATER CONTENT, DENSITY AND CBR VALUES SHOWN ABOVE WERE OBTAINED ON UNDISTURBED SAMPLES TAKEN IN CBR MOLDS.

WATER CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT

VARIATION OF CBR AND DENSITY WITH WATER CONTENT ON UNDISTURBED SAMPLES TAKEN IN CBR MOLDS

SECTION 5-34,50Q-LB TRACTOR-3 COVERAGES

.., C) c ::0 f'1

1\)

DEPTH 3" 30

>- zo z::l

"'" U< ~ ~ 10 II.

~

"' ., 0 u 0 w ~ s 20

"'" 0:<( a:o 0111 u ~ 10

0

IZfl

.... IZO .. :;) u

"' ... Ill> II.

"' ., ..J

~ 110

>-'::

"' 105 z w 0

>-a: 100 0

115 5 10 15

WATER CONTENT IN PERCENT DRY WEIGHT

NOTE: ALL WATER CONTENT, DEN!.ITY AND CBR VALUES SHOWN A80VE WERE OBTAINED ON UNDISTURBED SAMPLES TAI\f:N IN C8R MOLDS.

30

>- zo zo w"' v" "'~ ~en 10

~ a: .,

0 <J

0 .... 88 20

~~ 8 ~ 10

0

IZ5

>- IZO ... :;) <J

a: w 115 II.

"' ., ..J

~ 110

>-':: "' 105 z w 0

>-a: 100 0

zo Qfl 5

WATER

DEPTH 12" DEPTH 24" 30

t- 0 20 zw

"'" v< a:O ~ U) 10

~ a: ., 0 <J

0 w t c 20

"'"' "'" a:< oo u"' ;,o

0

IZ5

>- IZO ... :;) u

"' "' 115 II.

"' ., ..J

~ 110

>-'::

"' 105 z w 0

>-

"' 100 0

10 15 zo 95 5 10 IS zo

CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT

VARIATION OF CBR AND DENSITY WITH WATER CONTENT ON UNDISTURBED SAMPLES TAKEN IN CBR MOLDS

SECTION 3-250-PSI SHEEPSFOOT ROLLER- 9 PASSES

..., G) c :;o 1"'1

1\) 1\)

30

020 ....... zx loJ<( 00 a: I/) 10 "' Q.

!: a: 0 ., 0

0 .... t; s 20 "'x ~(§ 011) oz 10

:::>

0

125

1- 120 u. :::> 0

a: 115 .... Q.

Ill Cll _J 110

!: > !: 105 II) z "' 0

> a: 100 0

95

NOTE

DEPTH 3" 30

0 20 ........ 2:.:: "'-< oo f!illl 10 Q.

! a: ., 0 0

0 .... 8~ 20 a: X a:-< oo olll z 10 :::>

0

125

.... 120 "-:::> 0

a: 115 .... Q.

II) ., _J 110

!: > ....

105 iii z .... 0

>-a: 100 0

5 10 15 20 95

5 WATER CONTENT IN PERCENT ORY WEIGHT WATER

ALL WATER CONTENT, DENSITY AND C8R VALUES SHOWN ABOVE WERE 08TAINED ON UNDISTUR8ED SAMPLES TAKEN IN C8R MOLDS.

DEPTH 12" DEPTH 24" 30

1- 20 zo tj~ a:~ :till 10

~ a: ., 0 0

0

"' 1-~f;3 20 a:x ~(§ Olll ~ 10

0

125

1- 120 "-:::> 0

a: 115

"' Q.

II) ., _J 110

!: > 1-iii 105 z .... 0

>-a: 0

100

10 15 20 95

5 10 15 20 CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT

VARIATION Of CBR AND DENSITY WITH WATER CONTENT ON UNDISTURBED SAMPLES TAKEN IN CBR MOLDS

SECTION 2-450-PSI SHEEPSFOOT ROLLER-9 PASSES

., G) c ;D fTI

N w

30

20 0 .......

z" w~ li!lll 10 w II.

~ a: 0 ID u 0

~e 20 w>< a:~ "'Ill Oz u::> 10

0

12~

1- 120 ... ;:) u a: II~ ... II.

Ill ID ..J 110 ! ,.. !: Ul z 105 ... 0

> ~ 100

9~

NOTE:

DEPTH 3" 30

0 20 ....... d wo ~~~~ 10 w Q.

~ a: 0 ID u 0

~e 20

"" ~~ gill ..,z 10 ::>

0

12!1

1- 120 ... ::> u a: 115 ... II.

Ill ID ..J

!: 110

,.. 1-iii 105 z ... 0

> a: 0 100

95 !I 10 15 20 5

WATER CONTENT IN PERCENT DRY WEIGHT WATER

ALL WATER CONTENT, DENSITY AND CIIR VALUES SHOWN AIIOVE WERE OIITAINED ON UNDISTURIIED SAMPLES TAKEN IN CIIR MOLDS.

DEPTH 12" 30

DEPTH 24"

20 0

!z~ tl~ 0::111 10 w II.

! a: 0 ID u 0 w t;B 20 w" a:~ gill uz

::> 10

0

125

1- 120 ... ;:) u a: II~ ... II.

Ill ID ..J

z 110

,.. 1-iii 105 z ... 0

> a: 100 0

95 10 I~ 20 5 10 15 20

CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT

VARIATION Of" CBR AND DENSITY WITH WATER CONTENT ON UNDISTURBED SAMPLES TAKEN IN CBR MOLDS

SECTION 6-J,Soo-LB WOBBLE-WHEEL LOA0-6 COVERAGES

DEPTH 3" DEPTH 12" DEPTH 24" 30 30 30

20 20 0

20 ,_o 0

~~ ,_..,

z"' Z:.:: ..,.: "'< 1.)~ w< uo ffitJ'I 10

uO 10 "'"' 10 oc"' ..,

a. w Q.

Q.

~ ~ ~

oc 0 0 oc 0 oc "' Ill

"' 1.) 1.) 1.)

0 0 0

"' UJO 20 ~EJ 20 t::J 20 tiw

"':<: w:.:: w"' "'< a:< oc< a:o a:O a:O O<ll Q<ll o"' uz uz 10 uz 10 :l 10 :l :l

0 0 0

125 125 125

... 120 ,_ 120 ,_ 120 ... ... "-::> :::l ::> ' 1.) 1.) 1.)

a: 115 a: 115 a: 115 .., .., w Q. a. !l.

ell <I) <I)

"' "' "' -' -' -' 110 110 110

~ ~ ~

>- >- >-,_ ,_ ,_ iii 105 iii 105 iii 105 z z z UJ UJ w 0 0 0

>- ,.. ,.. a: 100 a: 100 a: 100 0 0 0

95 95 95 5 :o 15 20 5 10 15 20 5 10 15 20

WATER CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT

NOTE: ALL WATER CONTENT, DENSITY AND CBR VALUES SHOWN ABOVE WERE OBTAINED ON UNDISTURBED

VARIATION OF CBR AND D'ENSITY WITH WATER CONTENT SAMPLES TAKEN IN CBR MOLDS.

ON UNDISTURBED SAMPLES TAKEN IN CBR MOLDS SECTION 8-20,000-LB WHEEL LOAD-4 COVERAGES

30 DEPTH 3"

30 DEPTH 12"

30 DEPTH 24"

1-o 20 t- 0 20 t-O 20 ZUJ Zw zw

"'"' "'"' "'"' <)<( <)<( <)<(

a:o a:o o::o wUl 10 ~"' 10 :rU) 10 Q_

~ ~ ~

"' cr a:

Ill 0 Ill 0 Ill 0 <) <) <)

0 0 0 w "' "' t; 0 20 ~8 20 tJ 8 20

"'"' "'"' "'"' "'"' 0::<( a:< .,...: 0 a:o oO 00 0<1'1 u"' u"' u; 10 ; 10 ;10

0 0 0

125 125 125

t-120 t- t- 120 ... ... 120 ...

::> ::> ::> u u u

"' "' "' w a. 115 w 115 w 115

0. Q_

"' U) U) Ill _J Ill Ill

...J ...J

~ 110 ~

110 ~

110 ,.. ,.. >-~ U)

t- t-z 105 U) 105 U) 105

"' z z 0 w w

0 0 ,.. >- >-

"' 100 "' a: 0 0 100 0 100

95 95 95 5 10 15 20 5 10 15 20 5 10 15 20

WATER CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT

NOTE. ALL WATER CONTENT, DENSITY AND CBR VALUES SHOWN ABOVE WERE OBTAINED ON UNDISTURBED VARIATION OF CBR AND DENSITY WITH WATER CONTENT SAMPLES TAKEN IN CBR MOLDS.

ON UNDISTURBED SAMPLES TAKEN IN CBR MOLDS SECTION 9-40,000-LB WHEEL LOAD-4 COVERAGES

DEPTH 3" DEPTH 12" DEPTH 24" 30 30 30

1-020 !Z 020 t-o 20 zw

~~ ~ll! tl~ V< :i~ 10 ~~10 ~5ll0 Q.

:!: :!: ~

a: a: a: CD 0 CD 0 CD 0 u u u

0 0 0 ... ... ... ...

l;jo 20 te20 :.le2o ... ~ "'"' "'"' a:< "'< 8~ :!i~ :!i~ 0 ~10 u~ 10 ~10

0 0 0

1211 1211 1211

... 120 ... 120 ... 120 ... ... ... :;) :;) :> u u u a: a: 1111

a: 115 .. 11!1 "' ...

Q. ... Q. .., II) II)

II Ill Ill ...1 .J .J

! 110 :!: 110

~ 110

> > >-... ... ... w; 10!1 iii 10!1 iii 105 z z z .. "' ..

0 0 0

> >- >-a: 100 a: 100 a: 100 0 0 0

8!1 !I 10 I !I 20

8!1 5 10 15 20

9!1 5 10 15 20

WATER CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT

NOTE: ALL WATER CONTENT, DENSITY AND CBR VALUE$

VARIATION OF DENSITY !HOWN AIIOVE WERE OBTAINED ON UNDISTURBED CBR AND WITH WATER CONTENT SAMPLE$ TAKEN IN CBR MOLDS.

ON UNDISTURBED SAMPLES TAKEN IN CBR MOLDS SECTION 9-40p00-LB WHEEL LOAD-8 COVERAGES

.., G) c ;o fTI

1-z ... u a: ... Q.

; a: Ill u

Q ... t ... a: a: 8

20

Q 10 ... " c 0 .,

0

30

0 ... 1- 20 u ~ :ll 0 1.) 10

Cl)

c

0

12S

... ""120 :J u

a: ~II!;

Cl) ID .J

110 !; ,. 1-iii lOS z ... Q

,. a: 100 Q

9S

-

~

FIELD IN-PLACE TESTS 20

10 Q ......

Z" ... ~ ~CI) 0 ... Q.

~

a: 30 ID u Q

~ fl2o Ul-lo.ll.)

:f~ 0:1; uo 10

u

"' c

5 10 o5 05

12S

1- 120 ... ;) 1.)

15 115 Q.

., ID .J 110 ; ,. 1-iii lOS z ... Q

,. a: tOO Q

95 5 10 IS s

LEGEN{2 34,SOO·LB TRACTOR - 3 COVEP.AGES ZSO•PSI SHEEPSFOOT ROLLER -9 PASSES 450-PSI SHEEPSfOOT ROLLER -9 PASSES STD. AASHO EI'FORT MOO. AASHO EfFORT 2,000-PSI STATIC PRESSURE 1,500-LB WOBBLE-WHEEL LOAD- 6 COVERAGES ZO,OOO·LB WHEEL LOAD- 4 COVERAGES 40,000-LB WHEEL LOAD- 4 COVERAGES

CYLINDER TESTS FIELD IN-PLACE TESTS CYLINDER TESTS 20 20

.

Q 10

Q 10

. ...... ... ... Z" z" ... ~ ...~ l;?., li?CI) 0 0 ... "' Q. Q.

!; z a: 30 30 a: Ill Ill u u Q Q

~ ~20 ~~20 ....... Ut-a:U "'u a:~ a:c a: a. 0::~; 0::1;

' u 0 10 uo 10

u u Cl) ., . c c

10 I!; 05 10 15 05 10 15

125 12!;

IZO IZO ... ... ... ... :;;)

u :;;)

a: II 5 1.) liS a: .... .... -...: II. Q. ..

"' ., ~ 110 ~ 110

; ! ,. ,. t:1os Cl) ~lOS z z .... .... Q Q

i'i1oo ~ 100 Q Q

9S 9S 10 IS s 10 IS s 10 IS

WATER CONTENT IN PERCENT ORY WEIGHT

NOTE: I'IELO DATA SHOWN ARE FOR TESTS AND SAMPLES TAKEN IZ INCHES BELOW TOP OF

AND COMPACTED FILLS. COMPARISON Of FIELD LABORATORY COMPACTION AND CBR

, C) c ;:o Pl

1\)

(X)

<I)

a.

~

I:

~

25

~ 20

Iii ~

0 10 u 0 ... z ;;:: z 0 u z :::>

1-...

0

120

:::> 115 u a: "' 0.

110 <I) Ill .J

z ,.. 1-iii z

105

~ I 00 ,.. a: 0

34,000-LB TRACTOR

10 15 20 WATER CONTENT IN PERCENT DRY WEIGHT

NOTES: TESTS PERFORMED ON 211

BY 411

SPECIMENS CUT FROM UNDISTURBED TEST PIT SAMPLES. ALL SPECIMENS TESTED AT THE IN-PLACE WATER CONTENT AND DENSITY.

<I) a. z I: 25 I-

" z w a: 20 Iii

0 ... z ;;: z 0 u z :::>

1-...

0

120

a 115

a: ... 0.

<ll II 0 Ill .J

!: 105

250-PSI SHEEPSFOOT 450-PSI SHEEPSFOOT ;;; 30 0.

~

I: 25

1-.., z "' a: 20 1-<I)

w > iii 15 <I)

"' a: 0. ::ll 0 10 \J

0 w z

5 ;;: z 0 u z :::> 0

125

12 0

1-"-:::> 115 u a: w a. <I)

II 0 ., .J

~ 105

>-1-iii z w .oo 0

>-a: 0

955 ~=·-iii

: 100

1155 10 15 20 10 15 20

WATER CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DFiY WEIGHT

VARIATION OF UNCONFINED COMPRESSIVE STRgNGTH AND DENSITY WITH WATER CONTENT

UNDISTURBED SAMPLES

., G) c ::0 f11

1\) co

1500-LB WOBBLE WHEEL ROLLER 20,000-LB WHEEL LOAD AFTER 4 PASSES 40,000-LB WHEEL LOAD AFTER 4 PASSES 40,000-LB WHEEL LOAD AFTER 8 PASSES

~ Q.

:I: t­CJ z UJ

30

a: 20 lii w > iii 15

"' w a: Q.

~ 10 \)

0 w z 5 t;: z 8 z ::> 0

125--

t-120 ' ...

_j 110 z

>-1-iil1o.; z "' 0

>-15100

10 15

"' Q.

~

:I: t-CJ z w a: 1-

"' w > iii

"' w a: Q_

::!: 0 \)

0 w z t;: z 0 \) z ::>

25

20

I~

10

5

0

125

t 120

::> \)

a: 115 "' Q.

~ Ill _J 110

~

>-1-

~105 w 0

>-15100

95 5

NOTES' TEST PERF"ORMED ON 2' BY 411

SPECIMENS CUT FROM UNDISTURBED TEST PIT SAMPLES.

ALL SPECII\4€NS TESTED AT THE IN-PLACE WATER CONTENT AND DENSITY.

'

10 15 WATER CONTENT IN

~ ~ ~ ~

~ ~ 25 25

I I 1- t; CJ z z w w a: 20 a: 20 1- tii "' w w > 15 > 15 iii iii ~ "' w w a: a: Q. Q. ::!:

10 ::!: 10 0 0 \) \)

0 0 w "' z 5 ~ 5 t;: "-z z 0 0 \) \)

z z ::> 0 ::> 0

125 125

t;:l20 t;:120

::> ::> \) \)

:5 115 ~ 115 Q. Q.

"' ~ Ill Ill _j _j

110 110 ~ ~ >- >-1- 1-

~ 105 ~105 w "' 0 0

>- >-15100 ~100

95 95 5 10 15 5 10 15

PERCENT DRY WEIGHT

VARIATION OF UNCONFINED COMPRESSIVE STRENGTH AND DENSITY WITH WATER CONTENT

UNDISTURBED SAMPLES

...... (;) c ;o f'T1

w 0

30 ;; ... ~ %

~ .. at: t;

20

.. > Oi .. 1& .. at: ... 2 8 10

Q .. z ;;: z 0 u z ~ 0

... 120 ... a at: ~ 11!1

~ ! 110

... ... Oi z 10&

:!: ,.. ! 100

.. Q.

z % 25 ... " z :1! 20 t; .. > ~ 1!1

"' at: ... 2 0 10 u 0

"' z ;;:

~ ::> 0

1- 120 ... ::> 0

a: ~ 115

~ .J

! 110

... 1-

~ 105

"' 0 ,.. at: 0 100

& 10 15 20 WATER CONTENT IN PERCENT ORY WEIGHT

"' > :: 15

"' a: Q.

2 8 10

0

"' z .. z 0 0 z ::> 0

... 120 ... :::l 0

a: "' 115 Q. .. II) .J

z 110

... .... iii z 105

"' 0

lr 0 100

5 10 15 20 WATER CONTENT IN PERCENT DRY WEIGHT

5 10 15 20 WATER CONTENT IN PERCENT DRY WEIGHT

WATER CONTENT VS DENSITY AND UNCONFINED COMPRESSIVE STRENGTH

LEGEND

WATER CONTENT VS DENSITY AND UNCONFINED COMPRESSIVE STRENGTH

WATER CONTENT VS DENSITY AND UNCONFINED COMPRESSIVE STRENGTH

~--­~-­~-.--

D----

34,500-LB TRACTOR -3 COVERAGES 250-PSI SHEEPSFOOT ROLLER-II PASSES

45Q-PSI SHEEPSFOOT ROLLER-9 PASSES l,&oo-LB WOBBLE-WHEEL LOAD-II COVERAGES 40,000-LB WHEEL LOAD-4 COVERAGES 40,000-LB WHEEL LOAD·& COVERAGES

MODIFIED AASHO STANDARD AASHO

VARIATION OF UNCONFINED COMPRESSIVE STRENGTH AND DENSITY WITH FIELD COMPACTION EQUIPMENT