Performance of geopolymer concrete at elevated temperature − A critical review

Abstract

Concrete, renowned for its strength and durability, stands as the primary material in infrastructure construction. Despite its extensive use over millennia, its response to fire remains inadequately understood, posing threats to structural resilience and human safety. The consideration of fire resistance becomes paramount in selecting building materials. Throughout their operational lifespan, structures may encounter fire-related risks. Although there is a prevailing belief in the inherent fire resistance of concrete, its performance at high temperatures is subjected to alterations in both physical and chemical properties, impacting its strength and durability. Cracking and spalling may occur, resulting in economic losses and, in severe cases, loss of lives. Moreover, the production of concrete contributes to the depletion of natural resources, causing adverse environmental effects. In the world of building materials, the pursuit of innovative solutions for strength and resilience has been incessant. Consequently, researchers globally recognize the need for an environmentally friendly alternative to concrete. As concerns about fire safety grow, attention has shifted to geopolymer concrete, presenting itself as a promising eco-friendly substitute with significant potential to enhance fire resistance. Geopolymer concrete entirely replaces traditional cement concrete with waste materials rich in Alumina and Silica. Apart from mitigating environmental impacts, it exhibits superior resistance to high temperatures compared to ordinary Portland cement concrete, with the ability to endure temperatures ranging from 1000°C to 1200°C.Enhancements in the high-temperature behavior of geopolymer concrete can be achieved by incorporating materials such as fibers, marble powder, waste glass, rubber crumbs, nanoparticles, etc. This review explores the realm of geopolymer concrete, specifically delving into its fire-resistant properties. It provides a brief overview of the mechanical performance of geopolymer concrete subjected to elevated temperatures and elucidates the role of various materials in enhancing its behavior. It has been seen that in high temperature study of GPC, residual compressive strength is crucial and it mostly rises up to 150°−350°C but declines beyond 400°C due to micro-crack formation. Also, superior tensile strength is shown up to 300°C, with notable decline beyond 800°C. Incorporating fibers in GPC improves these residual properties. Different fibers, such as carbon, glass, basalt, polypropylene, and steel, have specific advantages and considerations. Recycled tire fibers prove cost-effective alternatives improving fire resistance in GPC, with an optimum content of 1.2–2 kg/m3.Usage of rubber particles in GPC prevent spalling at elevated temperatures by allowing water vapor escape, but increased amounts decrease compressive strength, while as using waste glass in GPC enhances microstructure, compressive strength and thermal stability but care is needed to address alkali-aggregate reactions. By comprehending the intrinsic characteristics and performance of geopolymer concrete with suitable additives at high temperatures, this paper aims to highlight its potential to revolutionize fire safety measures within the construction industry. This article not only initiates possibilities for future research on the fire-resistant qualities of geopolymer materials, but it also lays the groundwork for assessing elevated temperatures behavior of Geopolymer Concrete.