Construction & Building Materials Flashcards

What is the primary reason for using air-entrained concrete in cold climates?

Answer: Resist freeze-thaw damage

Entrained air voids provide pressure relief as pore water freezes and expands, preventing internal cracking from freeze-thaw cycling.

Which glass product is produced by rapidly cooling molten glass to create compressive surface stresses, making it 4-5 times stronger than annealed glass?

Answer: Tempered glass

Tempering creates surface compression that must be overcome before tensile cracking begins, increasing strength and causing the glass to dice into small cubes when broken.

What is the minimum concrete cover over steel reinforcement in a building column exposed to weather per ACI 318?

Answer: 2 in

ACI 318 requires a minimum 2-inch cover for concrete exposed to weather for bars larger than No. 5, protecting reinforcement from corrosion.

Galvanizing steel involves coating it with which metal to provide sacrificial corrosion protection?

Answer: Zinc

Zinc galvanizing provides both a physical barrier and cathodic (sacrificial) protection, oxidizing preferentially to protect the base steel.

What does 'slump' measure in fresh concrete?

Answer: Workability/consistency

The slump test (ASTM C143) measures the vertical drop of a standard cone of concrete, indicating its workability and relative water content.

In green building, what is the embodied carbon of a building material?

Answer: Total greenhouse gas emissions from material extraction, manufacturing, and transport

Embodied carbon encompasses all lifecycle GHG emissions (often expressed as CO₂e) associated with material production, transport, installation, and end-of-life.

Which type of mortar joint finish is most durable and weather-resistant for exterior masonry?

Answer: Concave (tooled) joint

A concave (rodded) joint compresses the mortar surface, sealing it against water infiltration and creating the most weather-tight finish.