_______, commonly found in soils in the western US, can cause concrete to break down due to chemical attack.

A longer yield plateau signifies a _______ ductile material.

Concrete strength increases with age.

Strength of concrete in a structure tends to be somewhat higher than the strength of the control cylinders made from the same concrete.

The concrete in the core of a spiral column is subjected to a uniform confining stress σ3 of 300 psi. What will the compressive strength σ1 be? The unconfined uniaxial compressive strength is 4,600 psi.

The concrete containing Type I cement in a structure is cured for 5 days at 43°F, followed by 2 days at 56°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.

High strength concrete usually has a lower paste content.

Given that dead load = 50 psf, live load = 100 psf, roof live load = 35 psf, snow load = 40 psf, and wind load = 40 psf, determine the largest factored load.

Lengths of reinforcing bars are generally given in 6-in. increments.

Permanent loads and the sustained portion of variable loads cause creep deformation in reinforced-concrete structures.