Sustainable fiber-reinforced strain-hardening composites using geopolymer as ‘Complete’ replacement of portland cement

Abstract

Strain-hardening cementitious composite (SHCC) is a special class of high-performance fiber-reinforced cementitious composites which exhibits strain-hardening behavior with very high tensile ductility of up to 5% at a moderate fiber content (2% or less by volume). Typically high cement content is used in this composite resulting in high autogenous shrinkage, heat of hydration, and cost. In addition, the associated increase in the CO2 emissions and embodied energy arising from the production of ordinary Portland cement (OPC) can compromise sustainability credentials of SHCCs. In the recent years the authors of this study developed an OPC-less strain-hardening geopolymer composite (SHGC). Geopolymer is used as ‘complete’ replacement of OPC in SHGC composition. Geopolymer is a sustainable alternative to OPC which emits at least 80% less CO2 and requires about 60% less energy as compared to production of OPC. The developed SHGCs are promising sustainable alternatives to typical SHCC, expecting to promote sustainability of the infrastructures via concurrent improvements of material greenness and infrastructure durability through very high tensile ductility and tight crack width control. This paper presents an overview of the authors’ research work on development and investigation of properties of SHGCs. The paper also presents a quantitative comparison of material sustainability performance of the developed SHGCs with typical SHCC.