Common use of Waterproof concrete Clause in Contracts

Waterproof concrete. Wherever waterproof concrete is shown on the drawings it shall be mix 1:1.5:3 nominal and it shall be compacted by mechanical vibration so that a dense and homogeneous mass of concrete is obtained throughout every pour of the structure. The Contractor shall be allowed at his own cost to add an approved waterproofing additive to the mix using it strictly according to makers‟ instructions. Specification Concrete Work (2/F/14) F.37 Waterproof concrete (Cont‟d.) All permanent construction joints shall be constructed in accordance with the drawings and specifications to achieve complete water tightness. It shall be the Contractor‟s responsibility to ensure that all structures required to be constructed in waterproof concrete are completely watertight and any work found to be defective shall be made good to the Architect‟s satisfaction at the Contractor‟s expenses. Where waterproof concrete forms a water retaining structure it is to be tested by filling with water for a period of not less than four days. Any percolation or porous concrete or leaking joint is to be made good at the Constructor‟s expense. Tanks and pools constructed below ground level are not to be backfilled prior to the satisfactory completion of this test.