Download Tender Document - High Commission of India, Colombo

Development of Atchchuvali Industrial
Estate in Jaffna District, Sri Lanka
Specifications – Waste Water Drainage System
10.02.3 Reinforced concrete pipes
Reinforced concrete pipe shall be used for trunk sewers, and all sewers ranging
from 300mm to 1000 mm in diameter.
The pipe interior shall be smooth and even, free from roughness, projections,
indentations, offsets, irregularities of any kind. The concrete mass shall be dense
and uniform. Concrete pipes shall be free from fracture, large or deep cracks,
and surface roughness. The planes of the ends of the pipe shall be perpendicular
to the longitudinal axis
Reinforced concrete pipes shall have a minimum nominal length of 2.0 m except
as otherwise specified or required for special purposes such as curves, closures
or built in pipes. The maximum nominal length shall be 6m.
Pipe joints shall be spigot and socket type with flexible water tight confined “Oring”
synthetic rubber gasket with neoprene elastomer. Joint details shall be
submitted to the Employers Representative for review and approval before
commencement of pipe manufacture.
All reinforced concrete pipe shall be spun and lined with 12.5 mm thick high
alumina lining consisting of 12.5 mm of sulphate resistant type V Portland
Cement (one part), Granite dust passing no. 100 BS sieve and 2 1//2 parts of fine
aggregate with sufficient clean water to ensure maximum density.
Interior surfaces shall be covered with two coats of an approved bituminous
coating. Coating shall be applied by the manufacturer at the plant.
10.02.4 High Density Polyethylene (HDPE) pipes
Corrugated PE pipes shall not be installed for sewers.
HDPE pipes will be used for branch sewers 280 mm in diameter or less installed
in areas with high groundwater table or on steep slopes.
High density polyethylene pipes for non-pressure sewers shall be class PE100,
pressure rated PN8.
All polyethylene pipes and fittings are to be joined by means of thermal fusion in
accordance with the recommendations of the manufacturer. Gasketed jointing
systems and couplers are not accepted.
10.03 Execution
10.03.1 Preparation
Clean pipes and fittings of debris and water before installation. Inspect materials
for defects before installing.
Remove defective materials from site.
10.03.2 Trenching and backfilling
Do trenching and backfill work shall be carried out in accordance with Section 2.4
of the General Specification
Trench line and depth as well as condition of trench bottom require approval prior
to placing bedding material and pipe.
July 2012 Page 3