Geopolymer synthesis using low-grade clays

Due to the large contribution of cement production towards CO2 emission and rising concerns regarding climate change, substitution with alternative binders has become an established improve sustainability. Aluminosiliceous polymeric materials, known as geopolymer or alkali activated have been proven achieve a performance good even superior ordinary Portland (OPC). Various source materials potential be used for synthesis depending on local availability, among which fly ash, slag, metakaolin received most attention. A less is low grade clay, whether natural clay waste construction work. These due their composition abundance worldwide. However, impurities present in these low-grade clays slower dissolution rates, synthesised geopolymers generally display lower mechanical performance. In this research, four different collected form sites Melbourne, Australia, were characterised, optimum selected based amorphous content, specific surface area, fineness. Furthermore, relatively energy-demand calcination regime was applied chosen 550° C 1 h. For untreated clay-based geopolymer, 7-day compressive strength nearly 32 MPa achieved, increased approaching 50 after at C. range microscopy techniques, EDS, XRD, XRF, zetametry, 27Al MAS NMR, computerised tomography characterise microstructure reaction kinetics geopolymer.