A REVIEW OF GEOPOLYMER MORTARS INCORPORATING INDUSTRIAL ASHES, CONSTRUCTION AND DEMOLITION WASTE (CDW), AND RECLAIMED ASPHALT PAVEMENT (RAP)

Abstract

The construction sector is facing greater challenges in reducing its impact on the environment, with the rising issue of waste that Construction and Demolition waste (CDW) and Reclaimed Asphalt Pavement (RAP) are creating for construction industries worldwide. An extensive research review on the existing technology for geopolymer ash-based mortar composites using locally available fine materials, with special consideration for building demolition waste and RAP, counted as more favorable cement replacement materials for geopolymer matrices, is conducted. Based on a broad analysis of 67 scholarly articles published between 2015 and 2026, this research presents a summary of existing technology with regard to three vital parameters: (a) the mechanical characteristics of geopolymer mortar composites, including compressive strength, flexural characteristics, durability, and workability; (b) the sustainability factors concerning the impact on the environment, through geopolymer potential for carbon footprint reduction, life cycle analysis, and sustainability assessment techniques; and (c) the chemical aspects concerning geopolymerisation kinetics, microstructure formation, and alkali activation mechanisms for geopolymer composites. The research findings suggested that geopolymer-based matrices using 25-50% demolition waste and RAP potentially have compressive strength values from 15 to 64 MPa with a reduction of 40-72% in carbon footprint compared to conventional PC-based systems. Geographic context, along with various application examples, such as implementation of the method with appreciable success in a variety of climatic conditions worldwide. From pavement-quality concrete to various forms of masonry mortars, the variety of structures is appreciable. Critical analysis of the field reveals existing research gaps with regard to the standardization of mix design methodologies and scaling issues. Review of existing literature offers an exhaustive framework for researchers working on the stream of sustainable construction materials through waste management practices.