Abstract
Geopolymers are a kind of emerging cementitious materials that provide an environmentally alternative to ordinary Portland cement (OPC) based concrete. Compared with OPC concrete, the benefits of geopolymers are mainly based on their ability to bring high volume ratio of industrial wastes into construction products. Generated via the dissolution and polycondensation reaction of aluminosilicate vitreous in industrial waste under high alkaline conditions, geopolymers possess the zeolite-like network structures in which aluminum and silica tetrahedrally interlink alternately by sharing all the oxygen atoms. The formation of this three-dimensional structure leads to ceramic-like properties. Therefore, geopolymers are generally considered to provide excellent fire resistance, and research in this field has been attracting increasing interest in recent years. Geopolymeric concrete is a multiphase composite material, and its composition has wide variations. The orthotropic nature of the constituent materials results in the variation of high-temperature performance. Owing to the considerable research efforts, it has been recognized that there are mainly three factors which can affect compressive strength of geopolymeric concrete (exposed to high temperature): (Ⅰ) phase transition; (Ⅱ) microstructure changes; (Ⅲ) thermal incompatibility of geopolymer matrix and aggregates. The compressive strength of geopolymeric concrete under (or experienced) high temperatures depends on the dominant factor and the material's ductility. In this paper, the influence of Si / Al ratio, type of alkali solution and aggregates on the compressive strength of geopolymeric concrete under (and after experiencing) high temperatures are discussed. Combined with three factors, the compressive strength degradation mechanisms of geopolymeric concrete is analyzed. The paper also summarizes the thermal performance of geopolymers and the fire resistance of geopolymeric concrete structures. Finally, the future research prospect of high temperature performance of geopolymers is discussed.
Translated title of the contribution | Research progress on high temperatures erformance of geopolymers |
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Original language | Chinese (Simplified) |
Article number | 21060242 |
Number of pages | 9 |
Journal | Materials Reports |
Volume | 37 |
Issue number | 8 |
DOIs | |
Publication status | Published - 25 Apr 2023 |