In the relentless battle against chloride-induced corrosion in concrete structures, a novel approach is emerging from the labs of Chulalongkorn University in Bangkok, Thailand. Researchers, led by Boonchai Stitmannaithum from the Center of Excellence in Innovative Construction Materials, have turned to an unlikely ally: prestressed rubber strips. Their findings, published in *Case Studies in Construction Materials* (translated as “Studies on Construction Materials”), could revolutionize the way we protect and extend the life of reinforced concrete bridge piers in harsh marine environments.
Chloride attack is a persistent problem for concrete structures exposed to seawater or de-icing salts. Traditional repair methods often fall short, providing only temporary fixes rather than long-term solutions. Stitmannaithum and his team sought to address this challenge by introducing beneficial compression to the concrete, thereby enhancing its durability and resistance to chloride ingress.
The team focused on short-span bridge piers, a common structure in coastal and bridge infrastructure. They used plain Para rubber pads, stretched to various degrees, to apply external compression to the concrete. The results were striking. “Applying compressive force via pre-stretched rubber strips significantly reduced chloride diffusion,” Stitmannaithum explained. “The most effective reduction was achieved at 100% elongation, demonstrating the potential of this technique to extend the service life of marine-exposed concrete structures.”
The research involved both accelerated testing, where specimens were immersed in a highly concentrated chloride solution, and long-term field exposure in brackish water. The consistency in diffusion coefficients across both methods confirmed that the concrete’s permeability was the primary factor controlling chloride ingress. This consistency allowed the team to focus on the effectiveness of the prestressed rubber strips in mitigating this ingress.
But the benefits didn’t stop at prevention. The team also assessed degraded piers, simulating reinforcement corrosion from chloride attack. They found that post-tensioning with Para rubber strips not only restored but also enhanced the flexural capacity and ductility of the piers. “Improvements were most notable in specimens with greater reinforcement loss,” Stitmannaithum noted, highlighting the technique’s potential to breathe new life into aging infrastructure.
The implications for the energy sector are substantial. Coastal infrastructure, including oil and gas platforms, wind turbines, and desalination plants, often face the dual challenge of harsh environmental conditions and high chloride exposure. The use of prestressed rubber strips could provide a cost-effective and durable solution for protecting these critical structures, reducing maintenance costs, and extending their operational lifespan.
Moreover, this innovative approach could reshape the future of construction materials and techniques. As Stitmannaithum’s research demonstrates, the key to long-term durability lies in understanding and manipulating the fundamental properties of materials. By introducing beneficial compression, we can enhance the performance of concrete structures, making them more resilient to the challenges posed by chloride attack.
In an industry often resistant to change, this research offers a fresh perspective and a promising solution. As we strive to build more sustainable and durable infrastructure, the use of prestressed rubber strips could become a game-changer, paving the way for a new era of innovative construction materials and techniques. The future of concrete, it seems, is not just about strength and stiffness, but also about flexibility and adaptability.