The Korea Institute of Civil Engineering and Building Technology (KICT) announced the development of an efficient method for structural reinforcement of concrete. The scientists used a non-combustible carbon textile mesh and cement mortar, which can double the bearing capacity of structurally defective concrete structures and extend their service life by three times. The development is reported by the Materials magazine.
Initially, almost all infrastructure in South Korea (over 90%), including bridges, tunnels, and residential buildings, was built of concrete. For worn out or structurally defective concrete structures in need of reinforcement, carbon fiber sheets are usually applied to the surface of the structure using an organic adhesive. However, such adhesives are susceptible to fire and cannot be applied to structures with damp surfaces. These carbon fiber sheets can come off and fall if exposed to moisture.
The KICT research team led by Dr. Hyun-Yeol Kim has developed an effective method to reinforce worn concrete structures. This method uses thin prefabricated textile-reinforced mortar (TRM) panels. It consists of a carbon textile mesh and a thin layer of grout. The TRM amplification method can be applied as a monolithic structure. Using the KICT method, 20mm TRM panels are bonded to the surface of the existing structure, and then the space between the existing structure and the panels is filled with cement mortar, which serves as an adhesive.
Both carbon textiles and grout are non-combustible materials that are highly fire-resistant. This means they can be effectively used to reinforce concrete buildings that may be at risk of fire. The new method can also be applied on wet surfaces in winter, while the panels do not fall off even if water gets in. In addition, unlike steel reinforcing bars, carbon textiles do not corrode and thus can be effectively used to reinforce road structures and parking lots, where de-icing agents are often used, as well as reinforce offshore concrete structures that are exposed to sea salts.