Concrete is an ideal sub floor material, but its porous nature can also lead to problems. Anyone who has worked with flooring and dealt with floor coverings on concrete can relate to any number of issues where moisture and what comes along with it has affected a job negatively.
Concrete is made up of a number of pores within its structure. These pores are perfect paths for moisture to travel from the surrounding soil, through the concrete and into a structure. Alkali salts can also permeate through the slabs when they are dissolved within the moisture vapor. The moisture and the alkali can affect the floor covering, especially if it isn’t noticed for a while. When the substance reaches the surface of the floor, it can cause corrosion, staining and more damage.
Alkali-silica reaction is a chemical reaction that takes place between the silica found in the aggregate within the concrete and the alkaline cement paste. Nicknamed “concrete cancer,” ASR can cause serious cracking problems in the concrete surfaces.
The best way to reduce the risk of alkali reaching the surface of a concrete floor is to limit the alkali metal content of the cement and limit the silica content of the aggregate. Because it is hard to treat ASR, it’s best to use preventative measures so that problems never take place.