The Influence of Rice Husk Additives on the Properties of Glass Based—Geopolymer at High Temperatures

Abstract

Foaming or porous geopolymers can be utilized in various engineering applications, including heat and acoustic insulations, as well as passive fire protection in building materials. They are ecofriendly materials, as no significant production power is required. In this study, geopolymers possessing foaming features involving lightweight and porous materials were successfully created through the reaction of sodium hydroxide solution 6 M with powder of waste glass MG without/with rice husk (RH) 20 wt.% of heat treated (212, 420, and 600 μm) utilized as the foaming agent. The effect of rice husk ash (RHA) and various sizes of RH additives on the thermal treatment (volume and weight changes, percentage), compressive strength, and microstructure (pore content) was assessed. The results show swelling (foaming behavior) for MG-N6, MGB-N6, MGR212-N6, and MGR600-N6 at 550°C, unlike the MGR420-N6 formula. Also, a high-volume change (percentage) for MGR420-N6 paste at 650°C was noticed. Additionally, foaming behavior (high volume expansion) appeared for all thoughtful pastes after treatment at 750°C. The weight loss for all specimens in the range of 10%–27% and a high percentage of weight changes for MGR400-N6 and MGR600-N6 were noticed. Low values of compressive strength (2.74–14.5 MPa) were recorded for all formulas studied. These synthesized materials, geopolymers containing glass waste and RH powder, resulting from this study, are highly recommended, mostly for thermal and acoustic insulation materials demanding lightweight, porosity, and low mechanical properties.