Foam concrete with mineral additives: from microstructure to mechanical/physical properties, workability and durability

This paper explores foam concretes produced from cement, sand, water, foaming agents and secondary cementitious materials (SCMs). We examine the effects of these constituents on the microstructure, mechanical/physical properties, workability, and the durability of foam concrete. The contributions of SCMs are assessed based on their pozzolanic activity. Various SCMs, through their pozzolanic reactivity, contribute significantly to pore refinement, matrix densification, and the enhancement of mechanical strength, thermal conductivity and durability characteristics, including resistance to water ingress, chloride penetration, and sulfate attack of foam concrete mixes. While the SCMs incorporation leads to improved strength, it may also increase brittleness, which can be balanced with the addition of fibers. Furthermore, the workability is greatly affected by the incorporation of SCMs, which often have a negative effect on reducing it. The paper highlights the opportunities to use metakaolin as an SCM for the optimization of foam concrete mechanical, durability and thermal properties.