Correct Answer : 2/3
Explanation : The general practice for structural light-weight concrete is to mix the aggregate and about 2/3 of the mixing water for a period upto one minute prior to the addition of cement and the balance mixing water.
Correct Answer : Option (D) : Aluminum oxide
Explanation : Powder form of aluminum oxide is used for fine polishing process. It is surface treatment process.
Correct Answer : Option (B) : IS 456-2000
Explanation : Option can be eliminated because there is no such code. Maximum nominal size of aggregates to be used in concrete may be as large as possible within the limits prescribed by IS 456:2000.
Correct Answer : Option (C) : 3-4
Explanation : This type of cement was first of all developed in U.S.A. It is recommended that air contents should be 03-04 % by volume.
