Performance evaluation of reinforced slag-fly ash-ceramic waste powders ternary geopolymer concrete under chloride ingress environment

Abstract

Ceramic waste powders (CWP) can be potentially used as precursors for preparing geopolymers. However, under marine environment, the influence of CWP on chloride resistance of geopolymer concrete and corrosion performance of the reinforcement embedded in geopolymer concrete are still not clear and needs to be clarified. This study systematically investigates the durability of reinforced slag-fly ash (FA)-CWP ternary geopolymer concrete under chloride ingress environments, aiming at elucidating the degradation mechanisms and providing theoretical basis for predicting service life of reinforced slag-FA-CWP ternary geopolymer concrete. By comparing workability, mechanical properties, chloride penetration resistance, drying shrinkage and steel corrosion resistance of C40-grade ternary geopolymer concrete with ordinary Portland cement (OPC) concrete, this research highlights the potential application of reinforced slag-FA-CWP ternary geopolymer concrete for marine environment. The results demonstrated that slag-FA-CWP ternary geopolymer concrete achieved workability and mechanical properties comparable to OPC concrete; further the ternary geopolymer concrete also exhibited denser pore structure and significantly lower chloride diffusion coefficient. During 240-day chloride immersion, steel embedded in slag-FA-CWP ternary geopolymer concrete maintained stable passive state, highlighting its superior anti-corrosion properties. These findings indicate that due to the retardation effect and micro-aggregate filling effect, the slag-FA-CWP ternary geopolymer concrete with excellent durability is a very promising green alternative to OPC under marine environment.