General Contractor License Site Work and Concrete 5

Question 1

The water-cement ratio in concrete directly affects which property?

Accepted Answer

Compressive strength and durability

Answer

A lower water-cement ratio produces higher compressive strength and better durability; excess water weakens the paste and increases porosity.

Question 2

What is the purpose of a geotextile fabric installed in a drainage aggregate layer?

Accepted Answer

To separate soil from aggregate and prevent migration of fines

Answer

Geotextile fabric acts as a filter that allows water to pass while preventing fine soil particles from migrating into and clogging the drainage layer.

Question 3

Cold weather concreting requires protecting fresh concrete because:

Accepted Answer

Freezing before adequate strength gain permanently damages the concrete

Answer

If fresh concrete freezes before reaching approximately 500 psi, ice crystals permanently disrupt the cement paste matrix, causing irreversible strength loss.

Question 4

What does 'bench cut' excavation mean?

Accepted Answer

Cutting stepped horizontal terraces into a slope to improve stability

Answer

Bench cutting creates horizontal steps (benches) in a slope, reducing the effective height of each exposed face and improving overall slope stability.

Question 5

Concrete consolidation by mechanical vibration is done primarily to:

Accepted Answer

Eliminate air voids and ensure complete aggregate encapsulation

Answer

Internal vibration removes entrapped air pockets and ensures concrete flows around reinforcement and into form corners for a dense, uniform matrix.

General Contractor License Practice Test

General Contractor License Practice Test

General Contractor License Site Work and Concrete 5