Rubberized Geopolymer Concrete for Sustainable Construction: A Critical Review of Interface Engineering, Performance Trade-Offs, Durability, and Environmental Impacts

The use of Rubberized Geopolymer Concrete (RGC) represents a sustainable solution that can reduce reliance on Portland cement and make use of the potential uses of waste-tire rubber in construction. This review paper critically evaluates the constituent materials, design parameters, rubber pretreatment, fresh and hardened properties, durability, microstructure, and performance-enhancement measures of RGC. It is found that higher content of rubber usually lowers the workability, density, compressive strength, and elastic modulus owing to the flexible nature of the rubber and poor interface bonding between rubber and geopolymer matrix. However, a suitable content of rubber can improve the deformability, toughness, shock-absorption capacity, vibration damping, and thermo-acoustic properties. Surface treatment and matrix modifications can improve the interface transition zone and partially minimize mechanical strength loss but the efficiency of the technique varies based on rubber content, precursor mixture, activator chemistry, and curing conditions. Some of the major future research gaps are a standardization of design and testing procedures, durability and structural scale validation, and life-cycle and techno-economic analysis. In future research, it should be considered to use multi-criteria optimization for improving the strength, ductility, durability, environmental impact, cost, and constructability of RGC.