PAGE 81

TABLE 300-1. DENSITY REQUIREMENTS OF EMBANKMENT AND SUBGRADE MATERIALS

_______________________________________________________________________

S.NoType of Work

Maximum laboratory dry unit weight when tested as per IS : 2720 (Part 8)

_______________________________________________________________________

1Embankments up to 3 meters

Not less than 15.2 kN/cu. m.

height, not subjected to

extensive flooding.

2Embankments exceeding 3

Not less than 16.0 kN/cu. m

Meters height or embankments

of any height subject to long

periods of inundation

3Sub grade and earthen shoulders/Not less than 17.5 kN/cu. m

verges/backfill

Notes: (1) This Table is not applicable for lightweight fill material e.g. cinder,

fly ash etc.

(2) The Engineer may relax these requirements at his discretion taking into

Account the availability of materials for construction and other relevant

Factors.

(3) The material to be used in sub grade should also satisfy design CBR at the

Dry unit weight applicable as per Table 300-2

TABLE 300-2 COMPACTION REQUIREMENTS FOR EMBANKMENT AND SUBGRADE

----------------------------------------------------------------------------------------------------------

Type of work/material

Relative compaction as percentage of max. laboratory dry density as per IS:2720 (Part8)

-----------------------------------------------------------------------------------------------------------------------------------------------------------------1.Sub grade and earthen shoulders

Not less than 97

2.Embankment

Not less than 95

3.Expansive Clays

a) Sub grade and 500 mm portion

Not allowed

just below the sub grade

b) Remaining portion of embankmentNot less than 90

Table 300-3 GRADING REQUIREMENTS FOR FILTER MATERIAL

Per cent passing by weight

Sieve Designation

Class I Class II Class III

53 mm

- - 100

45 mm

- - 97-100

26.5 mm

- 100 -

22.4 mm - 95-100 58-100

11.2 mm

100 48-100 20-60

5.6 mm

92-100 28-54 4-32

2.8 mm

83-100 20-35 0-10

1.4 mm

59-96 - 0.5

710 micron

35-80 6-18 -

355 micron

14-40 2-9 -

180 micron 3-15 - -

90 micron 0-5

0-4 0-3

TABLE 300-4 GRADING REQUIREMENTS FOR AGGREGATE DRAINSSieve Size

Per cent passing by weight

Type AType B

63 mm

- 100

37.5 mm

100 85- 100

19 mm

- 0-20

9.5 mm

45-100 0.5

3-35 mm

25-80 -

600 micron

8-45 -

150 micron

0-10 -

75 micron

0-5 -

TABLE 400 -1. GRADING FOR CLOSE-GRADED GRANULAR SUB-BASE MATERIALS

IS Sieve

Per cent by weight passing the IS sieve

______________________________________________________

Designation

Grading IGrading IIGrading III

75.0 mm 100--

53.0 mm

80-100100-

26.5 mm

55-90 70-100 100

9.50 mm 35-65 50-80 65-95

4.75 mm 25-55 40-65 50-80

2.36 mm 20-40 30-50 40-65

0.425 mm10-2515-2520-35

0.075 mm3-103-103-10

CBR Value (Minimum)302520

TABLE 400 -2. GRADING FOR COURSE GRADED GRANULAR SUB-BASE MATERIALS

IS Sieve

Per cent by weight passing the IS Sieve

______________________________________________________

Designation

Grading IGrading IIGrading III

75.0 mm 100--

53.0 mm

100

26.5 mm

55-75 50-80 100

9.50 mm

4.75 mm 10-30 15-35 25-45

2.36 mm

0.425 mm

0.075 mm