Steel corrosion is one of the primary reasons municipal and commercial concrete requires regular repair. Extensive corrosion can threaten the structure’s integrity and pose a serious risk to nearby property and people. What preventive measures are effective at both reducing and eliminating steel corrosion in concrete?
Why Is Steel Used as a Reinforcement Measure?
Concrete requires steel reinforcement to withstand the continual force and stress to which is it continually subjected. Road traffic, exposure to the elements and deicing chemicals can all have a devastating effect, but with the inner support of steel bars and sections, the structures last much longer than they would otherwise.
When the metal corrodes, the bond between the concrete and the metal is broken and the rust occupies more space, pushing on the concrete from the inside. Gradually, the material suffers many stress fractures, resulting in crumbling and cracking, which threaten the entire structure’s stability.
Why Does Steel Corrode?
Steel is normally integrated in concrete in extreme climates in which it is exposed to salt water or ice-melting chemicals. When the chloride found in these substances seeps into the concrete and makes contact with the steel, the corrosive process begins, as long as both water and oxygen are also present. While chloride is the fastest-acting steel corrosive substance, carbons can also create an environment with a neutral chemical balance which can lead to steel corrosion over time.
The first step in prevention comes before the structure is built, when the concrete is mixed. The water-to-cement ratio must be lowered by adding cement or cement-like substances to increase density and slow the absorption of chloride.
The American Concrete Institute also recommends an adequate amount of concrete cover poured over the steel bars. The cover should be at least 2 inches thick if the structure will come into contact with deicing chemicals and at least 2.5 inches thick for saltwater exposure.
Lengthy curing time frames are required to achieve corrosion protection. Additionally, regular application of water repellants, epoxy coatings or sealers can add further resistance to the structure.
Concrete repair projects can be straightforward and simple for those with experience working with the popular building material, but repairing steel corrosion can be a challenging process best left to a skilled, professional team. Contact Lift-Up Concrete for more information on how correct initial installation and regular maintenance can prevent steel corrosion of your concrete structure.