Geo-Engineering and Microstructural Properties of Geopolymer Concrete and Motar: A Review

Constant generation of industrial waste has taken a massive toll on the environment, and therefore, many researchers are continuously looking for ways to utilize these by-products effectively to mitigate the problems associated with it. Moreover, the amount of carbon dioxide (CO 2 ) emission has also increased dramatically due to the massive generation of cement, creating a serious threat to the environment. Geopolymer concrete (GPC) has been introduced as a better alternative to replace Ordinary Portland Cement-based concrete. The introduction of a new geopolymer material that can replace the traditional cement plug for upstream carbon capture and sequestration is the unique aspect of this research. Research findings reveal that as compared to conventional concrete, GPC exhibits excellent durability, higher compressive and flexural strength, faster setting time, low CO 2 emission and high temperature resistance, etc. This paper presents a comprehensive review of geo-engineering properties and microstructural behaviour of geopolymer concrete and mortar. Physical properties, chemical compositions, mechanical properties and microstructural changes of both the geopolymer concrete and mortar have been peer reviewed, with a focus on compressive strength, setting time, water absorption, durability, permeability and leaching of heavy metals. It has also been discussed how different chemical admixtures such as calcium sucrose, glucose, acetic acid solution, sodium sulphate and sodium hydroxide affect its characteristics. The effect of calcium silicate hydrate (C-S-H), and calcium aluminium silicate hydrate (C-A-S-H) phase matrix in geopolymer concrete and mortar has been discussed. Moreover, GPC with various secondary industrial waste materials with its prospective applications in the building industry, has been briefly addressed.