Engineered Geopolymer Composites (EGC) with Ultra-high Strength and Ductility

Abstract

Engineered Geopolymer Composites (EGC), also known as Strain-Hardening Geopolymer Composites (SHGC), are considered more environmentally friendly than their cement-based counterpart. This study for the first time presents EGC with an ultra-high compressive strength (i.e., over 150 MPa) and an ultra-high tensile ductility (i.e., over 9%) simultaneously. The blended use of fly ash (FA), ground granulated blast slag (GGBS), silica fume, alkali activator, and ultra-high-molecular-weight polyethylene fibers led to the successful development of “Ultra-high-strength & ductility EGC (UHSD-EGC)”. The UHSD-EGC were characterized with excellent multiple cracking and strain-hardening features. In addition, it was found that microstructures of FA-rich geopolymer matrix were looser than those with lower FA/GGBS ratios. The findings arising from this study provided a sound basis for developing EGC materials with ultra-high mechanical properties for sustainable and resilient infrastructure.