BRIEF REVIEW OF GEOPOLYMER BINDER

Abstract

Concrete is a famous component in construction due to the ease of work in shape and dimension. However, concrete is highly dependent on the availability of Ordinary Portland cement (OPC) as the binder. The survey recorded that OPC had environmental issues, especially CO2 release and the amount of energy expended during the production. Some researchers were motivated to answer these issues by reducing OPC in the concrete. Using geopolymer in the concrete binder was an alternative to solve the issue. This paper summarized the previous studies on geopolymer binder dealing with the material characteristics, rheology properties, microstructure, mechanical properties, durability, and applications in reinforced concrete. Geopolymer offered zero OPC as the binder in the concrete. It used the waste or by-product material as the base material in geopolymer concrete. The material of geopolymer was rich in the chemical content of Si, Al, and Ca that produced the gel of Si-O-Si and Si-O-Al to contribute to the compressive strength. While the gel of C-A-S-H or N-A-S-H contributed to the setting time. Geopolymer provided similar or better concrete properties compared to OPC concrete. This paper reviewed the properties of geopolymer concrete (GPC), which consisted of fresh and hardened properties, creep, drying shrinkage, and bond with reinforcement bars. This paper also displayed the factors influencing the GPC properties, the stress-strain relationship, and the structural behavior of reinforced geopolymer concrete members with the currently available conventional concrete standards. Finally, the GPC properties were comparable to those of OPC. However, the challenge of GPC in the future should answer its limitation in the concrete industry referred to in the previous study.