Site Work and Concrete Flashcards
7 cards from real General Contractor License practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Site Work and Concrete flashcards as text
The water-cement ratio in concrete directly affects which property?
Answer: Compressive strength and durability
A lower water-cement ratio produces higher compressive strength and better durability; excess water weakens the paste and increases porosity.
What is the purpose of a geotextile fabric installed in a drainage aggregate layer?
Answer: To separate soil from aggregate and prevent migration of fines
Geotextile fabric acts as a filter that allows water to pass while preventing fine soil particles from migrating into and clogging the drainage layer.
Cold weather concreting requires protecting fresh concrete because:
Answer: Freezing before adequate strength gain permanently damages the concrete
If fresh concrete freezes before reaching approximately 500 psi, ice crystals permanently disrupt the cement paste matrix, causing irreversible strength loss.
What does 'bench cut' excavation mean?
Answer: Cutting stepped horizontal terraces into a slope to improve stability
Bench cutting creates horizontal steps (benches) in a slope, reducing the effective height of each exposed face and improving overall slope stability.
Concrete consolidation by mechanical vibration is done primarily to:
Answer: Eliminate air voids and ensure complete aggregate encapsulation
Internal vibration removes entrapped air pockets and ensures concrete flows around reinforcement and into form corners for a dense, uniform matrix.
A 'benchmark' on a construction site is:
Answer: A fixed reference point of known elevation used for surveying
A benchmark is a permanent, precisely established reference point with a known elevation from which all site elevation measurements are taken.
What does 'segregation' mean when it occurs in freshly mixed concrete?
Answer: Separation of coarse aggregate from the cement paste and mortar
Segregation occurs when coarse aggregate separates from the paste, resulting in non-uniform concrete with weakened zones and poor surface quality.