The three most common durability problems in concrete structures are corrosion of steel in the concrete, breakdown of the structure of the concrete due to freezing and thawing, and breakdown of the structure of the concrete due to a chemical attack.

There is a permanent reduction in strength when concrete is exposed to sustained high loads.

A concrete cube is subjected to biaxial loading. Estimate the compressive strength σ1 if σ2 = 0.8 times the compressive strength, in compression.

Strength of concrete tends to decrease as the maximum aggregate size decreases.

Which of the following is not a common durability problem in a concrete structure.

Carbonation shrinkage occurs in carbon-dioxide rich atmospheres.

The concrete containing Type I cement in a structure is cured for 5 days at 53°F, followed by 3 days at 41°F. Use the maturity concept to estimate its strength as a percentage of the 28-day strength under standard curing. Maturity is defined as M = Σ(Ti + 50)(ti) where Ti is in degrees F and ti is in days.

The concrete containing Type I cement in a structure is cured for 2 days at 68°F, followed by 2 days at 42°F. Use the maturity concept to estimate its strength as a percentage of the 28-day strength under standard curing. Maturity is defined as M = Σ(Ti + 50)(ti) where Ti is in degrees F and ti is in days.

A longer yield plateau signifies a _______ brittle material.

A concrete cube is subjected to biaxial loading. Estimate the compressive strength σ1 if σ2 = 0.2 times the compressive strength, in compression.