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 size of a modular brick in the United States?
Answer: 3-5/8" × 2-1/4" × 7-5/8"
A standard modular brick measures 3-5/8 inches wide × 2-1/4 inches tall × 7-5/8 inches long, which equals 4" × 2-2/3" × 8" with mortar joints.
What is the purpose of control joints in a concrete slab?
Answer: To provide locations where cracking can occur in a controlled manner
Control joints create weakened planes in concrete slabs that guide shrinkage cracking to occur at planned locations rather than randomly across the slab.
What is the minimum concrete cover required for rebar in a slab exposed to weather in the US?
Answer: 1-1/2 inches
ACI 318 requires a minimum of 1-1/2 inches of concrete cover over reinforcing steel in slabs exposed to weather to protect against corrosion.
What is the correct mortar type for load-bearing masonry walls?
Answer: Type M or S
ASTM C270 specifies Type M or Type S mortar for load-bearing and below-grade masonry due to their higher compressive strengths.
What is 'admixture' in concrete mix design?
Answer: A material added to concrete to modify its properties
Admixtures are materials added to concrete in small quantities to modify properties like workability, setting time, air content, or durability.
What is the purpose of air entrainment in concrete mixes used in freeze-thaw climates?
Answer: To create microscopic air bubbles that relieve freeze-thaw pressure
Air-entrained concrete contains microscopic air bubbles that provide relief space for water expansion during freezing, preventing surface scaling and cracking.