Question

question 1
random hairline cracks in the concrete garage floor are usually caused by
○ shrinkage during curing
○ heaving
○ settlement
○ de - icing salts
○ poor drainage

Explanation:

Random hair - line cracks in concrete garage floors often occur due to the concrete shrinking as it cures. During the curing process, water evaporates from the concrete, causing it to contract. Heaving is usually related to frost - action or expansive soils, settlement is due to ground movement, de - icing salts can cause surface scaling and deterioration over time, and poor drainage can lead to water - related issues like erosion or hydrostatic pressure problems, but not typically random hairline cracks.

Answer:

shrinkage during curing