Paddy Engineering Consultant

SUITABILITY OF WATER FOR CONCRETE MIXING OBJECTIVE To assess suitability of water for use in concrete mix. EQUIPMENT Measuring cylinder Cube moulds Trowel Tamping rod Vibrating table Testing machine PROCEDURE Analyse water for its chemical compositions as per  IS 3025-1964  and compare these with permissible limits given in  IS: 456-2000 .In case water does not satisfy the permissible limits or it is not possible to obtain chemical analysis data readily, the suitability of water is tested by making concrete cubes. Concrete of desired grade is prepared with available water with designed proportions and cubes casted for testing. Prepare the same concrete mix with distilled water and cast the cubes in exactly the similar manner as with water of unknown nature. Cure both the sample in respective water under exactly the same conditions. Test both the cube specimens after 7 and 28 days in exactly the same manner. Compare the test results of strength and cond...

DURABILITY OF CONCRETE PILES Properly mixed concrete compacted to a dense impermeable mass is one of the most permanent of all constructional material and give little cause of concern about its long-term durability in a non aggressive environment. However, concrete can be  attacked by sulphate and sulfuric acid  occurring naturally in soils, by corrosive chemicals which may be present in industrial waste in fill materials and by organic acids and carbon dioxide present in ground water as a result of decaying vegetable matters. Attack by sulphates is a disruptive process whereas the action of organic acids or dissolved carbon dioxide is one of leaching. Attack by sulphuric acid combines features of both processes. The severity of attack by soluble sulphates must be assessed by determining the soluble sulphate content and the proportions of the various cat ions present in an aqueous extract of the soil. These determinations must be made in all cases where the concentration of s...