What is the Nominal mix and design mix ?

Question

Accepted Answer

Nominal mix is a mix of fixed proportions of cement, sand and aggregate. Design mix is a mix of desired proportions of cement, sand and aggregate.

Nominal mix is used for small construction works and where quality control is not a major concern.
Design mix is used for large construction works and where quality control is a major concern.
Nominal mix has fixed proportions of materials, usually 1:2:4 for M15 grade concrete.
Design mix has desired proportions of materials based on the strength and durability requirements of the structure.
Nominal mix is not recommended for reinforced concrete structures.
Design mix is recommended for reinforced concrete structures.
Nominal mix is cheaper than design mix.
Design mix is costlier than nominal mix.

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