Concrete and Masonry Flashcards
6 cards from real Construction practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Concrete and Masonry flashcards as text
What is the standard water-to-cement ratio range for most structural concrete mixes?
Answer: 0.45–0.60
Most structural concrete uses a water-to-cement (w/c) ratio of 0.45–0.60; lower ratios increase strength while higher ratios improve workability but reduce strength.
What is the purpose of rebar (reinforcing steel) in concrete?
Answer: To resist tensile stresses that concrete cannot handle
Concrete is strong in compression but weak in tension; rebar is embedded to carry tensile forces and prevent cracking under loads.
What is the minimum curing time for standard Portland cement concrete to achieve adequate strength?
Answer: 7 days
Concrete should be cured for a minimum of 7 days for adequate strength development; however, the standard 28-day strength is used for design purposes.
What does the designation 'f'c = 4000 psi' mean for concrete?
Answer: The specified compressive strength at 28 days is 4000 psi
f'c denotes the specified compressive strength of concrete measured in pounds per square inch (psi) at 28 days after placement.
What is the purpose of a slump test for concrete?
Answer: To measure the workability and consistency of fresh concrete
The slump test measures the workability (flowability) of fresh concrete by measuring how much a cone of concrete settles after the cone mold is removed.
What type of mortar joint is most water-resistant and recommended for exterior masonry?
Answer: Concave (tooled) joint
A concave (tooled) joint is the most weather-resistant mortar joint because the tooling compresses and seals the mortar surface, preventing water infiltration.