PACKAGE : I Bid Document VOLUME : II - Public Health Engineering

(viii) Increased cover thickness shall be provided for surfaces exposed to the action
of harmful chemicals or exposed to earth contaminated by such chemicals
acids, alkalis, saline atmosphere, sulphurous smoke etc. and such increase of
cover may be between 15mm and 50mm beyond the figures mentioned here
as may be specified by the Engineer.
(ix) For liquid retaining structures, the minimum cover to all steel shall be 40mm
or the diameter of the main bar, whichever is greater. In the presence of soils
and waters of a corrosive character, the cover shall be increased by 10mm.
(x) The correct cover shall be maintained by cement mortar cubes or other
approved means. Reinforcement for footing, grade beams and slabs on sub
grade shall be supported on precast concrete blocks as approved by the
Engineer. The use of pebbles or stones shall not be permitted.
(xi) The 28 day crushing strength of cement mortar cubes/precast concrete cover
blocks shall be at least equal to the specified strength of concrete in which
these cubes/blocks are embedded.
(xii) The minimum clear distance between reinforcing bars shall be in accordance
with IS:456.
9.10 Inspection.
All continuous inspections shall be performed by the engineer’s representative.
Erected and secured reinforcement shall be inspected and approved by the Engineer
prior to placement of concrete.
9.11 Reinforcement Bars Procurement.
Steel reinforcement, such as M.S. bars, High yield strength deformed bars etc.,
required for the works shall be procured by the contractor. The contractor shall
arrange for transport, loading, unloading and storage at the work sites. The
contractor should plan the procurement of steel in such a way that at least required
quantity of steel of specified sizes is available at site for 3 months period.
GTS : General Technical Specification. Page 75