Mitigating the Effects of Road Salt on Concrete

Concrete is 10% cement, 30% sand, 40% gravel, and 20% air and water. Cement is made up primarily of lime (60-65%), silica (17-25%), and alumina (3-8%).

Concrete can be damaged by the freeze/thaw cycle of water seeping into pores in the concrete which causes hydraulic pressure build-up and cracking.

Chloride salts such as calcium chloride, magnesium chloride, and sodium chloride are often used to minimize the freeze/thaw cycle by lowering the freezing point of the water.

Unfortunately, these salts can lower the alkaline pH (usually around 11) of the concrete in addition to leaching the calcium hydroxide from the cement, weakening the structure of the concrete.