Quality Assurance Handbook for Rural Roads Volume-I - pmgsy

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Quality Assurance Handbook for Rural Roads
pipe. Make a continuous layer of well compacted sand, moorum or approved granular
material, passing 5.6 mm sieve and shaped concentrically, to fit the lower part of the pipe
exterior for a minimum 10 per cent of its overall height. The compacted thickness of the
granular bedding layer shall not be less than 75 mm.
(iii) For expansive soils, provide a layer of sand/moorum on non-expansive material of minimum
450 mm thickness under the bedding.
3 Back filling
(i) The back fill of soil shall be clean from borders, large roots, clay lumps retained on 75 mm
sieve, stones retained on 26.5 mm sieve and excessive amounts of sods and other vegetable
matter.
4 Tolerances
The following tolerances are permitted for concrete pipes as per IS 458
i. Overall length ±1 percent of standard length
ii. Internal dia ±10 mm
iii. Barrel thickness
80-95 mm + 5 mm
-2.5 mm
Over 95 mm +7 mm
-3.5 mm
5. Quality Control Tests
5.1 Tests prior to construction
The quality control tests to be carried out prior to construction are indicated in Table 1100.1.
TABLE 1100.1: QUALITY CONTROL TESTS PRIOR TO CONSTRUCTION
S.No. Material / Work Test / Check Frequency
1. Bricks As in Table 600.6 As in Table 600.6
2. Stones As in Table 700.6 As in Table 700.6
3. Concrete Pipe - Dimensions At factory before delivery
- Manufacturing defects
- Tolerances (IS:458)
- Three edge bearing test (IS:3597) Manufacturer’s certificate
5.2 Tests / Checks during construction
The Quality Control Tests / checks to be carried out during construction are indicated in Table
1100.2.