The Korea Institute of Civil Engineering and Construction Technology (KICT) has announced the development of an effective method of structural concrete reinforcement. Scientists have used a non-combustible carbon textile mesh and cement mortar that can double the load-bearing capacity of structurally defective concrete structures and extend their life span by three times. The Materials magazine reports about the development.

Initially, almost the entire infrastructure in South Korea (over 90%), including bridges, tunnels and residential buildings, was built of concrete. For worn or structurally defective concrete structures that need reinforcement, carbon fiber sheets are usually applied to the surface of the structure using organic adhesives. However, such adhesives are subject to fire and cannot be applied to structures with wet surfaces. These carbon fiber sheets can detach and fall off if exposed to moisture.

The KICT Research Group, led by Dr. Hyun-Yol Kim, has developed an effective method to strengthen worn concrete structures. This method uses panels made of thin prefabricated textile reinforcement mortar (TRM). It consists of a carbon textile mesh and a thin layer of cement mortar. The TRM reinforcement method can be applied as a monolithic structure. Using the KICT method, 20mm thick TRM panels are attached to the surface of an existing structure, and then the space between the existing structure and the panels is filled with cement mortar, which serves as glue.

Fracture test of concrete slab reinforced with TRM panel. Photo: Korea Civil Engineering and Building Technology Institute (KICT).

Both carbon textiles and cement mortar are non-combustible materials with high fire resistance. This means that they can be used effectively to reinforce concrete buildings that can be exposed to fire hazard. The new method can also be used on wet surfaces in winter, and the panels do not fall even if water gets in. In addition, unlike steel reinforcement rods, carbon textiles are not susceptible to corrosion and can thus be effectively used to reinforce road structures and parking lots, where de-icing agents are often used, and to reinforce sea concrete structures that are exposed to sea salts.