In spite of being hailed for its exceptional durability, concrete usually deteriorates when exposed to certain environments or conditions. If your commercial structures are made of concrete, it is important to be aware of some common causes of concrete failure.
Here are 3 typical causes of concrete deterioration that you should know about:
Freeze-thaw disintegration
Water expands considerably when it freezes. Concrete is permeable, and so, if water seeps in and freezes, small crumbs of concrete disintegrate from the surface. As temperatures continue to drop, the water in wet concrete freezes and expands, exerting pressure in the pores and capillaries of the concrete. If the pressure generated supersedes the tensile strength of the concrete, it will dilate and break even further. Deicing salts such as sodium chloride, used to remove snow and ice from concrete, can exacerbate freeze-thaw deterioration. This typically is because deicing salts impact more damagingly on concrete under freezing conditions. The accumulative impact of continual freeze-thaw cycles can eventually culminate in significant expansion and cracking, crumbling, and scaling of the concrete.
Chemical attack
Generally, concrete can withstand exposure to various atmospheric conditions, soil, water, and many other types of chemical exposures remarkably well. Concrete hardly ever reacts with solid, dry chemicals. Aggressive chemicals must be present in and above a certain minimum concentration before they can cause any significant attacks on concrete.
Some chemical environments, however, are so harsh that they can degrade even high-quality concrete. The damaging effects of some common chemicals, such as calcium bisulfide, aluminum chloride, sulfuric acid, hydrochloric acid, nitric acid, etc., on concrete occur very rapidly. The chlorides and nitrates of magnesium, iron, ammonium and aluminum can all cause concrete wear, with those of ammonium being notorious for causing the most damage.
Corrosion of reinforcing metal
Even though corrosion of reinforcing steel is in itself a chemical process, it is important to separate it from other chemical processes that often lead to degradation of concrete material. It is common practice for concrete contractors to reinforce concrete with steel. In essence, steel is often embedded in the concrete to boost its structural strength. When steel begins to corrode, the rust that is subsequently formed takes up a greater amount of space than the steel. This leads to formation of an expansive product (rust), which in turn causes tension in the concrete, and this can eventually cause concrete degradation in terms of cracking, spalling, and delamination. This type of concrete deterioration occurs via chemical reaction.
If you run into any of these problems or have noticeable damage on your concrete, contact professionals that specialise in concrete repair.
