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
What is the purpose of vapor retarder under a concrete slab-on-grade?
Answer: To prevent soil moisture from migrating up through the slab
A vapor retarder (typically polyethylene sheeting) prevents ground moisture from wicking up through the concrete slab.
Reinforcing steel cover in concrete refers to:
Answer: The minimum distance from the rebar surface to the concrete surface
Cover is the minimum thickness of concrete between the surface and the nearest reinforcing bar, protecting steel from corrosion and fire.
What is 'blowout' in the context of concrete formwork?
Answer: Sudden failure of formwork under hydrostatic concrete pressure
Formwork blowout is a sudden structural failure caused by the lateral hydrostatic pressure of fresh concrete exceeding the formwork's capacity.
In soil classification, 'cohesive' soils primarily include:
Answer: Clay and silt
Cohesive soils such as clay and silt have particles that stick together due to electrochemical forces rather than friction.
What does 'compaction factor' refer to in earthwork calculations?
Answer: The ratio of compacted fill volume to the bank (in-place) volume from which it came
The compaction factor (or swell/shrinkage factor) accounts for volume changes when soil is excavated and recompacted in a new location.
Which type of pile is driven into the ground and derives its capacity primarily from skin friction along its length?
Answer: Friction pile
Friction piles transfer structural loads to surrounding soil through friction and adhesion along the pile shaft rather than bearing on a hard layer.
What is the primary purpose of a subdrain (French drain) installed in a retaining wall?
Answer: To relieve hydrostatic water pressure behind the wall
A subdrain behind a retaining wall removes accumulated groundwater to prevent dangerous hydrostatic pressure buildup that could cause wall failure.