Use of Geopolymer and Carbon Fiber-Reinforced Polymer for Repairing Reinforced Concrete Deck Soffit

Abstract

This study aimed to assess the feasibility of utilizing geopolymer for repairing reinforced concrete beams. Three types of beam specimens were fabricated: benchmark specimens without any grooves, rectangular-grooved beams, and square-grooved beams. The repair materials employed included geopolymer material, and epoxy resin mortar, while carbon fiber sheets were used as reinforcement in select cases. The repair materials were applied to the rectangular and square-grooved specimens, with the carbon fiber sheets attached to the tension side of the specimens. To evaluate the flexural strength of the concrete specimens, a third-point loading test was conducted. The test results indicated that the geopolymer exhibited higher compressive strength and shrinkage rate compared to the epoxy resin mortar. Furthermore, the specimens reinforced with carbon fiber sheets demonstrated even greater strength than the benchmark specimens. In terms of flexural strength under cyclic third-point loading tests, the carbon fiber-reinforced specimens exhibited the ability to withstand over 200 cycles of repeated loading at 0.8 times the ultimate load. In contrast, the benchmark specimens could only withstand seven cycles. These findings highlight that the use of carbon fiber sheets not only enhances compressive strength but also improves resistance to cyclic loading.

A Study on the Shrinkage and Compressive Strength of GGBFS and Metakaolin Based Geopolymer under Different NaOH Concentrations

“…This calcination process eradicates the hydroxyl groups in the kaolin, transforming it into a more reactive, amorphous MK, ideal for effective geopolymerization [ 37 , 38 , 39 ]. Additionally, an MK-based GP is particularly suitable for repair applications, given its mechanical properties closely resembling those of OPC and its superior tensile strength [ 40 , 41 , 42 ].…”

Geopolymers Based on a Mixture of Steel Slag and Fly Ash, Activated with Rice Husks and Reinforced with Guadua angustifolia Fibers

“…Reinforced concrete is used in structures subjected to tensile and bending efforts, generally with steel rods [2]. These reinforcements improve the system's behavior under tensile stresses, reducing the susceptibility to failure when the structures are exposed to the action of winds, thermal cycles, and traffic [3]. However, when steel is exposed to corrosive environments, a bond between steel and concrete is lost.…”