DID YOU KNOW?

The life of concrete is limited by a number of disintegrating effects:

WEATHERING

Weathering by rain and frost action is chiefly a function of water-tightness or impermeability, since leach and attack by the carbonic and other acids present in rainwater, and disruption by frost action, depend on the penetration of water into the surface. Chemical attack such as industrial chemicals and wastes; sewage; animal and vegetable oils, fats, grease; milk; and sugars. Wear by abrasion from foot and vehicular traffic, by wave actions, and by water-borne and wind-borne particles.

VOIDS

Concrete has the tendency to be porous due to the presence of voids formed during or after placing. It is usually necessary in order to obtain workable mixes, to use far more water than is actually necessary for chemical combination with the cement. This water occupies space, and when it later dries out, it leaves behind air voids.

GASES

Gases such as sulphur dioxide and carbon dioxide in damp situations, attack concrete. Sulphuric acid also attacks concrete, but the attack from sulphuric acid is likely to be accompanied by abrasion. Sulphates of sodium potassium, magnesium and ammonium may cause serious damage to Portland cement concrete in the presence of moisture. This begins by expansion within the concrete, which may be enough to cause general expansion in the member.