High-temperature performance of geopolymer mortars containing ceramic filter press cake and pottery waste powders

Abstract

The sustainable management of Ceramic Tile Filter Press Cake Powder (FPW) and Pottery Shard Waste Powder (PW) is crucial to reducing environmental harm in the ceramics sector. These ceramic byproducts offer a valuable source of aluminosilicate powders, which can be used in the synthesis of geopolymer mortars as an innovative alternative to traditional raw materials. This study focuses on repurposing these materials as binders in geopolymer mortars and evaluating their performance after exposure to elevated temperatures. Geopolymers were formulated with varying FPW/PW ratios (100/0, 75/25, 50/50, 25/75, 0/100) and cured thermally at 90°C for either 6 or 24 h. Strength tests were conducted on mortars before and after heating at 400, 600, and 800°C. Selected samples underwent crystal structure (XRD) and microstructural (SEM/EDX) analyses both before and after thermal exposure. The results indicated that 24-hour cured geopolymers exhibited better initial strength, while the 6-hour cured mortars demonstrated superior residual strength post-heating. Geopolymers with higher FPW content displayed greater thermal resistance than those with higher PW content. Overall, ceramic waste proved to be a viable alternative material for producing geopolymers, offering an effective solution for waste reduction in the ceramics industry.