Comparison between Portland cement concrete and geopolymer concrete based on metakaolin and granulated blast furnace slag with the same binder volume

Abstract

Under the serious concerns of environmental degradation due to the greenhouse gas emissions of ordinary Portland cement (OPC) industry, geopolymer concretes have been qualified as a good alternative to OPC concretes. Geopolymer concretes, known by their good mechanical and durability properties, possess different fresh and hardened behaviours as compared to OPC concretes. This reason is one of the main obstacles that hinder the deployment of these concretes worldwide. Furthermore, geopolymer concretes developed in the literature are mostly based on fly ash while only few works were carried out on geopolymer concrete based on a blended mix of metakaolin (MK)/granulated blast furnace slag (GBFS). In this context, this paper aims to compare the fresh and hardened properties of geopolymer concrete based on MK and GBFS as well as OPC self-compacting concrete (OPSCC) with the same volume of binder. At fresh state, the workability evolution during the first hour after mixing was followed. At hardened state, mechanical strengths, dynamic modulus of elasticity, water porosity and shrinkage are investigated with a special attention to the early age behaviour.