Chloride-Induced Steel Corrosion And Solutions

Chloride-Induced Steel Corrosion And Solutions

Sustainability is one of the prime focuses of attention in the concrete industry in North America. From creating concrete structures with a low environmental impact and adaptation of the building process to longer life of concrete structures, it’s important for the construction industry to build sustainable RC structures.

Regardless of the region or climate, reinforced concrete structures built with traditional materials deteriorates due to chloride attacks and other phenomena. The primary action of chlorides is to corrode steel reinforcement.

Corrosion is one of the major problems that affects the durability of reinforced concrete structures. Both chloride-induced and carbonation-induced corrosion are common phenomena in civil infrastructure across the globe. Billions of dollars are spent just to maintain steel-reinforced structures and to slow down the corrosion process. The spalling and cracking in concrete due to corrosion and the reduction in the cross-sectional area of reinforcing bars lead to structural deficiencies.

Chloride-induced corrosion of steel

Corrosion of steel reinforcement has been one the most pressing durability issues in RC design. Depassivation of the protective thin oxide film of the reinforcing bars and chloride ingression initiate corrosion. Corrosion of reinforcement not only degrades the appearance of a structure but also reduces its safety and strength. In waterside structures where concrete has to encounter a high concentration of chloride, it becomes critical to implement long-lasting materials. When it comes to environmental deterioration of RC structures, chloride-induced corrosion is a major concern.

RC is a widely used building material. It is cost-effective, versatile, and easily available. If designed and executed properly, concrete allows a variety of applications and forms. However, the penetration of chloride ions, carbon dioxide, or sulphate into RC leads to rapid degradation. As mentioned earlier, the corrosion of the embedded steel is the main reason why RC structures deteriorate.

The service life of RC structures can be divided into two parts: propagation and initiation. Initiation is described as the time until depassivation of steel is detected. It’s important to have knowledge of chloride ingress rate and the critical condition for depassivation design initiation phase. The propagation period requires knowledge of the corrosion rate in order to predict structural integrity.

GFRP fiberglass rebar: a reliable solution to chloride-induced corrosion

Advanced composite materials like glass fiber-reinforced polymer (GFRP) reinforcing bars are corrosion-free materials that provide a durable solution to chloride-induced and other forms of corrosion that rapidly degrade the strength of a concrete structure. As an inherently corrosion-resistant material, GFRP rebar makes it possible to build RC structures that can achieve a long service life while requiring very minimal maintenance.

In Canada and the United States, the construction industry is now realizing the need for GFRP and other composite materials that provide sustainable and cost-effective construction solutions. TUF-BAR is a leading fiberglass rebar manufacturer in Canada and across North America. We manufacture and sell a range of GFRP construction products including rock bolts, dowels, and fencing panels. Contact us to learn more about our products.