Mechanical properties of sustainable metakaolin/Rockwool based geopolymer mortar

Rockwool wastes occupy colossal space, and burying them causes environmental issues. Reusing them in construction might have many advantages for the environment and material properties. In this paper, Rockwool wastes (RW) and metakaolin (MK) are used as base materials for making the environmentally-friend geopolymer mortar with different ratios. Implemented alkaline solution in this research is composed of sodium hydroxide (SH) and sodium silicate (SS). Compressive strength, flexural strength, electrical resistivity, and ultrasonic pulse velocity are evaluated in this study. The effect of some parameters in mix proportions, such as liquid to solid ratio, RW/MK ratio, SH molarity, and silicate modulus (SS/SH ratio), are studied on the experimental outputs. It is observed that the samples with less RW/MK ratio, less liquid-to-solid ratio, and more molarity value have better durability and mechanical properties. The outputs show an optimum value of 1.5 for silicate modulus (SM), and the best durability and mechanical properties belong to such samples. The outputs are also estimated using the artificial neural network, and this conclusion is drawn that this tool can efficiently estimate experimental results of RW and MK-based geopolymers. The microstructure of hardened geopolymer mortar samples is also studied in this paper.