Repair and Rehabilitation of Damaged Reinforced Concrete Beams Using Sustainable Geopolymer Composites

Abstract

Cement is one of the most used building materials worldwide. However, using cement affects the environment negatively by increasing CO2 emissions during its manufacturing process. In addition to that, concrete structures are exposed to different types of damage and defects during their service life, which increases the need for early repair and maintenance. Several repair techniques have been developed and used, such as using Portland cement concrete/mortar, steel, fiber-reinforced polymer, and ultra-high-performance concrete. However, some of these techniques have been observed to have drawbacks, including higher CO2 emissions, low fire resistance, aging of adhesion materials, and corrosion and debonding of repairing materials. Therefore, there was a need to develop a green construction material that can be utilized in the repair and rehabilitation of damaged reinforced concrete RC structures. Accordingly, current work is focused on studying the eligibility of using geopolymer composites as green and sustainable materials to repair damaged RC structures. The obtained results of this study showed that the optimum GPM mix that can be used in repair applications may be made of 50% FA, 50% GGBS, and 5% SP. The SS/SH of the optimum mix could be 1.0. Exposing the coarse aggregate of concrete substrates contributed to improving the strength of the bond between the optimum GPM and concrete substrates by 29% and using the optimum GPM to repair law-damaged RC beams at a repair depth of 25 mm helped to enhance the ultimate moment capacity of repaired RC beams by about 10%.