JAUE2024-061: Self-healing Efficiency of Fly ash-based Geopolymer- A Review

Abstract

The employment of bacteria to repair microcracks in cement concrete has garnered extensive research interest. Geopolymer binders, as an alternative to Portland cement, exhibit superior physical and mechanical properties, as well as durability. Their potential for bacteria-induced self-healing ability has thus emerged as a significant area of study. Under the influence of air, water and nutrients, bacteria consume CO2 and additional calcium sources to synthesize CaCO3. This CaCO3 precipitates around the cracks, thereby facilitating the repairing of cracks. Generally, alkali activators include NaOH solution and Na2SiO3 solutions. The efficiency of bacteria suitable for cement concrete self-healing may be compromised under the influence of alkaline conditions, subsequently affecting self-healing efficiency. Furthermore, variable curing conditions can influence bacterial viability. This paper provides a comprehensive review of the impact of activators on bacteria self-healing efficiency and elucidates the self-healing performance under different curing conditions. XRD, and SEM are used to confirm the healing products. Crack sealing capability, compressive strength recovery and water permeability are used to evaluate healing efficiency.