Sand replacement

test

Objective

Student should be able to : -

Determine the in situ density of natural or compacted soils using sand pouring cylinders.

Theory

By conducting this test it is possible to determine the field density of the soil. The

moisture content is likely to vary from time and hence the field density also. So it is

required to report the test result in terms of dry density. The relationship that can be

established between the dry density with known moisture content is as follows:

This test is to be conducted by laboratory staff to determine the degree of

compaction after the layer of sand fill or DG material has been compacted .

1. Hand dig an insitu core sample from the compacted soil and weigh to get the mass of test sample . [ Note : It is usually to pick out the occasional gravels and cobbles that are of relatively big size before weighing since they are not the same type of material as the sample]2. Pour into the subsequent void with fine sand of consistent and known density ( eg. Quartz sand ) to calculate the volume of the void which is equivalent to the volume of the test sample. [ Note : Put back the gravels and cobbles into the void before pouring in with quartz sand ]3. Get the mass of the sample after oven-dried and divided by the volume of void to obtain the dry density of the sample .4. Divide the dry density of sample by the proctor test result , ie. the maximum dry density of the respective sample to obtain the relative percentage of compaction .5. The acceptance criteria for these percentage depends on the specification requirements and is generally as follows : -

* No less than 98% within 150mm below formation level . *No less than 95% between 150mm and 1200mm below formation . *No less than 90% beyond 1200mm below formation level .

Equipment

1. Sand pouring cylinder

2. Tools for excavating holes

3. Cylindrical calibrating container

4. Metal containers

5. Metal tray

5. Pan Balance – sensitive to 0.1 gram

procedurei) Calibration

1) Fill the sand-pouring cylinder with sand, within about 10mm of its top. Determine the mass of the cylinder (M1) to the nearest gram.

2) Place the sand-pouring cylinder vertically on the calibrating container. Open the shutter to allow the sand run out from the cylinder. When there is no further movement of the sand in the cylinder, close the shutter.

3) Lift the pouring cylinder from the calibrating container and weigh it to the nearest gram (M3).

4) Again fill the pouring cylinder with sand, within 10mm of its top.

5) Open the shutter and allow the sand to run out of the cylinder. When the volume of the sand let out is equal to the volume of the calibrating container, close the shutter.

6) Place the cylinder over a plane surface, such as a glass plate. Open the shutter. The sand fills the cone of the cylinder. Close the shutter when no further movement of sand takes place.

7) Remove the cylinder. Collect the sand left on the glass plate. Determine the mass of sand (M2) that had filled the cone by weighing the collected sand.

8) Determine the dry density of sand, as shown in the data sheet, part-I.

ii) determination of bulk density of soil

1. Place the sand pouring cylinder concentrically on the top of the calibrating container with the shutter closed making sure that constant mass (M0) is maintained

2. Open the shutter of cylinder and allow the sandto move into the container. When no futher movement is seen, close the shutter and find the mass of sand left in the cylinder (M2)

3. Repeat step 2-3 at least thrice and find the mean mass (M2)

a) b) c)

iii) determination of field density of soil

1) Level surface of the soil inthe open field

2) Place metal tray on the surface haring a circular hole of 10cm diameter at the center. Dig a hole of this diameter up to about 15 cm dept. Collect all the excavation soil in a tray and find the mass of excavation soil (M)

3) Remove the tray and place the sand-pouring cylinder concentrically on the hole. Open the shutter and allow the sand to run into the hole till no futher movement of sand is noticed. Close the shutter and determine mass of sand which is left in the cylinder , (M3)

4) The representative sample is taken from the excavated soil for determination of water content..

a) b) ’ c)

d)

DATA & RESULT

Determination of mass of and in the cone

No Test 1

Volume of calibrating container (m3), Vc 11.39

Mass of sand in cylinder before pouring (M0) (kg) 9.374

Mean mass of sand in cone, (M1) (kg) 0.494

Determination of bulk density of sand

No Test 1Mean mass of sand leave in cylinder after pouring (M2) (kg)

7.299

Mass of sand filling calibratung container (Mc = M0 – M1 – M2)

1.581

Bulk density of sand (ρs = Mc / Vc ) (kg/m3) 0.139

Determination bulk density and unit weight of soil

Mass of wet soil from the hole (M) (kg) 1.169

Mass of sand in cylinder after pouring in the hole (M2) (kg) 7.127

Mass of sand in the hole, (Ms = M0 – M1 – M3 ) (kg) 1.753

Bulk density of soil , ρ = M / Ms x ρs (kg/m3) 4.798

Dry density of sand ρd = ρ / ( 1 + w ) 4.505

No of cone 1

Wet soil 0.079

Dry Soil 0.077

Cone Weight 0.046

Water Content % 6.5 %

Calculation

Vc = πr2h

= π (5)2 (0.145)

= 11.39 m 3

Mc = M0 – M1 – M2

Mc = (9.374 – 0.494 – 7.299)

= 1.581

ρs= Mc / Vc

= (1.581 / 11.39 )

= 0.139 kg/m 3

Ms = M0 – M1 – M3

= (9.374 – 0.494 – 7.127 )

= 1.753 kg

ρ = M / Ms x ρs

= 1.169 / ( 1.753 x 0.139 )

= 4.798 kg/m3

ρd = ρ / ( 1 + w )

= 4.798 / (1 + 0.065 )

= 4.505

DISCUSSIONDiscussion

1. What is the objective of sand replacement test?

Determine the in situ density of natural or compacted soils using sand pouring cylinders.

2. What is the relationship that can be established between the dry density with known

moisture content?

3. What are the apparatus that need in this test?

There are Sand pouring cylinder,tools for excavating holes,cylindrical calibrating

container,metal containers,metal tray,weight scales.

4. Discuss the different method of compaction of :

a) Cohesionless soilb) Cohesive soilc) Cohension less soils cannot be compacted by static pressure, vibration is

the only effective method.d) Cohesive soils are not susceptible to vibration, static pressure is the

method of compaction for cohesive soils and kneading also works.

ConclusionConclusion

What we can conclude from the test is sand replacement is determine the in situ density of natural

or compacted soils using sand pouring cylinders.

The relationship that can be established between the dry density with known moisture content is as

follows:

Sand replacement method (standard method, but does not apply to fill a big stone embankment

and other porous materials, holes or large degree of compaction test) is the use of the basic

principles of particle size 0.30 ~ 0.60mm or 0.25 ~ 0.50mm uniform clean sand, from the the

whereabouts of a certain high degree of freedom to the test inside the cave, according to their unit

weight the same principle to measure the volume of test hole (ie, using standard test hole sand to

replace the aggregate), and in accordance with the moisture content of aggregate to calculate the

sample The measured dry density. 

Reference

1. Donald Mcglinchey, Characterisation of bulk solids, 2005, CRC Press DT Afrika.

2. Mazlan Mohammad Abdul Hamid, Standard aggregate sieve analysis TEST, ASTM International - Standards Worldwide, (July 2008) ASTM C136-06, retrived from http://www.astm.org/

3. Norliza Muhammad, concrete laboratory,(2006). Gradation Test. (2007), Norliza Muhammad, FajarBakti.Sdn.Bhd

no title page

1 objective 4

2 theory 5

3 Equipmnet 6-7

4 procedure 8-10

5 Data and analysis 11-13

6 discussion 14

7 conclution 15

8 reference 16