Geopolymer Made from Kaolin, Diatomite, and Rice Husk Ash for Ceiling Thermal Insulation

Abstract

In this study, geopolymers made of metakaolin (MK), diatomite (D), and rice husk ash (RHA) were developed for ceiling thermal insulation in houses to provide protection against cold temperatures. The influence of the constituent mixing ratio and the temperature of curing on the heat conductivity and compressive strength of the geopolymer was investigated. Specimens were formed according to a 10-level mix design with three replicates and subjected to curing at 40 °C and 80 °C. Heat conductivity and compressive strength were determined in accordance with established standards. The simplex lattice method was used to obtain the response surfaces, contour plots, and tracking curves. The geopolymers under study displayed a reduction in heat conductivity and an increase in compressive strength when the curing temperature was raised. The optimal mixing ratio to achieve a balance between the compressive strength and thermal conductivity of the geopolymers investigated was 0.50 MK and 0.50 RHA. Diatomite’s thermal insulation contribution is neutralized when crystals from the geopolymer gel fill the pore volume. The mixture’s optimal results were achieved when cured at 80 °C, demonstrating a thermal conductivity of 0.10 W/m·K and a compressive strength of 5.37 MPa.

Improving Sag Resistance in Geopolymer Coatings Using Diatomite Filler: Effects on Rheological Properties and Early Hydration

“…Due to the numerous internal pores in geopolymer coatings, diatomite can act as a fine aggregate filler [ 48 ]. Initially, due to its higher water absorption, an increase in diatomite concentration results in higher adsorption of free water, thereby slowing down the progress of geopolymer hydration reactions [ 84 ].…”

“…Diatomite is a resource-abundant and economically viable natural mineral. With its unique microporous structure, large specific surface area, and high reactivity, it can effectively enhance the freezing resistance [ 43 ], thermal stability [ 44 , 45 ], adsorption capacity [ 46 , 47 , 48 , 49 ], and mechanical strength [ 44 , 50 , 51 , 52 ] of geopolymer materials. It is therefore regarded as an effective additive for improving the durability of geopolymer materials.…”