Compressive strength is _______.

A wall footing has the following conditions. Determine the minimum width of the footing.The bottom of the footing is at a depth of 3 ft below grade.The service dead load is 12 kips/ft, and the service live load is 7 kips/ft.The wall is 12 in. thick.The footing is 15 in. thick.The allowable soil pressure, qa, is 5,500 psf.The soil has a density of 125 lb/ft3.The concrete has a density of 150 lb/ft3.The concrete cover has a thickness of 3 in.f’c = 3,200 psi and fy = 60,000 psi.

Which grade of reinforcing bars is most commonly used in buildings and bridges?

At very slow loading rates, the strength of concrete decreases.

A wall footing has the following conditions. Determine the distance to the neutral axis, c, measured from the top of the footing. Assume the footing is 6 ft wide, the pressure that acts on the bottom of the footing is 4,866 psf, and the reinforcement is a #8 bar spaced every 12 inches.The bottom of the footing is at a depth of 5 ft below grade.The service dead load is 15 kips/ft, and the service live load is 7 kips/ft.The wall is 16 in. thick.The footing is 13 in. thick.The allowable soil pressure, qa, is 4,500 psf.The soil has a density of 115 lb/ft3.The concrete has a density of 150 lb/ft3.The concrete cover has a thickness of 3 in.f’c = 4,000 psi and fy = 60,000 psi.

At high loading rates, the strength of concrete increases.

Microcracks that occur along the interface between paste and aggregate are called _______ cracks.

Exceptional shrinkage can occur when concrete is _______.

Concrete subjected to a temporary axial load greater than the critical load will eventually fail under loads less than the critical load.

A wall footing has the following conditions. Determine the pressure that acts on the bottom of the footing. Assume the footing is 4 ft wide.The bottom of the footing is at a depth of 2 ft below grade.The service dead load is 9.7 kips/ft, and the service live load is 6.9 kips/ft.The wall is 12 in. thick.The footing is 12 in. thick.The allowable soil pressure, qa, is 4,900 psf.The soil has a density of 115 lb/ft3.The concrete has a density of 150 lb/ft3.The concrete cover has a thickness of 3 in.f’c = 3,200 psi and fy = 60,000 psi.