Civil Engineering - Concrete Technology - Discussion

Where cement concrete 1:2; 4 ratio is used it means 1 part cement 2 parts of fine aggregate or coarse sand and 4 parts of coarse aggregate. This ratio cement concrete has good strength and is recommended for the following type of buildings and works:-

- Used in footings of columns and raft foundation, used in beams, slabs, columns, stairs and walls of ordinary, single story and temporary buildings and used in retaining walls, pavements, floors and bedplates etc.

- Where cement concrete 1:1:5:3 ratio is used it means 1 part cement 1.5 parts of fine aggregate or coarse sand and 3 parts of coarse aggregates. This ratio cement concrete has very good strength and is recommended for the following type of buildings and works:-

- Important RCC structures, piles, arches, impermeable construction against water heads. This ratio of cement concrete is safe against earth quake.

1:1.5:3 is M20 grade of concrete. 1:2:4 is M20 Grade of Concrete & for RCC minimum M20 grade is use as per IS 456-2000.

1:1.5:3, because is 456-2000 specifies min grade of concrete for rcc works is M20.

Minimum grade of concrete for R.C.C. work as per IS 456 is M20 which is 1:1.5:3.

Minimum grade of concrete for RCC work is M20 and proportion is 1 : 1.5 : 3.

For general R.C.C works in building, proportion of concrete is 1:1.5:3.

As per IS code, blow than M20 (1:1. 5:3) grades not used in Rcc work.

Yes, it is revised from m15 to m20, therefore ans is m20 i.e 1:1.5:3.

IS 456:2000 suggests a minimum M20 for RCX so the answer should be B.

Correct answer is 1:1/2:3 according to reference book by Khurmi.