Casagrand Civil Site Engineer Interview Questions and Answers

Grades of concrete refer to the strength of the concrete mix design.

• Grades of concrete are denoted by M10, M15, M20, etc. where M stands for mix and the number represents the compressive strength in N/mm^2.

• Higher grade concrete has higher compressive strength and is used for structural purposes.

• Common grades include M25, M30, M35, and M40 for heavy-duty structures like bridges and high-rise buildings.

Slump in concrete refers to the measure of consistency of freshly mixed concrete.

• Slump is determined by the amount of water in the concrete mix.

• It is measured by filling a cone-shaped mold with concrete, then lifting the mold to see how much the concrete slumps.

• Different types of slumps (true slump, shear slump, collapse slump) indicate different levels of workability and strength of the concrete mix.

• Slump test is comm...read more

Water cement ratio is the ratio of the weight of water to the weight of cement used in a concrete mix.

• Water cement ratio is a crucial factor in determining the strength and durability of concrete.

• A lower water cement ratio results in stronger and more durable concrete.

• The ideal water cement ratio varies depending on the type of concrete mix and its intended use.

• For example, a water cement ratio of 0.5 is commonly used ...read more

M20 grade concrete is a mix of 1 part cement, 1.5 parts sand, and 3 parts aggregate, with a compressive strength of 20 MPa.

• M20 grade concrete is commonly used in residential construction.

• It is a mix of 1 part cement, 1.5 parts sand, and 3 parts aggregate.

• The compressive strength of M20 grade concrete is 20 MPa.

• It is suitable for foundations, beams, columns, and slabs.