Rebars, or the steel reinforcements used in various concrete structures, are the unseen heroes of today’s construction industry. While they are concealed within the concretes we see — from roads to bridges to buildings — they do the crucial job of adding strength to infrastructures and in making the construction process itself faster and much more efficient.
Nonetheless, these rebars — though long-lasting, thanks to concrete reinforcement spacers and tying systems — aren’t exempted from getting broken, especially when exposed to damage-inducing things. One of the issues iron-made rebars face is rusting. And when not addressed or prevented, this concern can eventually affect the structural integrity of the whole concrete where the rebars were used.
What Causes Rusty Rebars
Rebars’ being embedded in concrete is actually a great help in protecting these steels from rusting. They are shielded from the outside environment, plus the concrete surrounding them acts as an alkaline protective layer against corrosion.
So, under what circumstances can rebars become rusty?
According to experts, exposure to salt is one of the main culprits behind this rather unfortunate phenomenon. The chloride ions found in salt can make their way through the concrete and cause rebars to corrode, and the structure itself to deteriorate.
But how can concrete be exposed to salt? This happens when the structure is located near a marine environment. Or when infrastructures like roads and bridges are applied with deicing salts to make them safe for driving during winter.
Another cause of corrosion in rebars is the crack that can appear in concrete over time. These cracks can be caused by changes in temperature and by too much stress and pressure.
With the presence of cracks, outside materials like water can enter the concrete and hasten the process of rusting.
How to Prevent Rebars From Getting Damaged
There are different ways as to how rebars or steel reinforcements can maximize their strength and durability.
What serves as these rebars’ first line of defense against corrosion is the so-called cover, which refers to the minimum distance between the rebars and the concrete. This cover ranges from 25 to 75 millimeters or 1 to 3 inches. The accuracy of maintaining this distance lies in the proper installation of the rebars’ framework — which involves using concrete reinforcement spacers and tying systems to ensure the steels are in place before the concrete is poured onto them.
However, even an adequate cover can still be not enough to protect rebars. This is why many now prefer adding glass, synthetic, and steel fibers to concrete to make it stronger and crack-resistant. While the rebars take care of resisting tension throughout the structure, these fibers, on the other hand, are in charge of handling localized tension.
In other cases, experts recommend using epoxy-coated rebars to prevent them from rusting easily. This is especially beneficial if the construction site is located in a corrosive environment. Others also advise using alternatives such as stainless steel and fiber-reinforcedd polymers. Just take note that these alternatives are generally much more expensive than the traditional steel reinforcements.
Straight 2 Site is a trusted source of concrete reinforcement spacers, tying systems, and other construction supplies and accessories. Contact us today for more info.
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