Strength Development and Elemental Distribution of Dolomite/Fly Ash Geopolymer Composite under Elevated Temperature

Traditional cement production contributes significantly to carbon emissions. Geopolymers offer a sustainable alternative. Dolomite is a potential raw material for geopolymers. However, its low reactivity limits its use. Prior research has shown that fly ash can enhance geopolymer properties. No prior work had resolved how dolomite/fly ash composites behave under heat. This gap motivated the current investigation. Existing studies focus on OPC or pure fly ash geopolymers. The behavior of dolomite-based geopolymers under elevated temperatures remains unclear. This paper contributes by analyzing strength and elemental distribution in dolomite/fly ash composites.

This study aimed to evaluate the performance of dolomite/fly ash geopolymer composites under heat. The specific problem is the limited use of dolomite due to its low reactivity. The motivation lies in finding a sustainable alternative to OPC. The researchers wanted to test how heat affects strength and elemental distribution. They also sought to compare DFA geopolymers with OPC and other geopolymers. The goal was to determine if heat improves DFA composite properties. This could lead to new construction materials with lower environmental impact. The study sought to provide data on strength and homogeneity at different temperatures.

The study used dolomite, fly ash, sodium hydroxide, and sodium silicate to create DFA composites. Compression tests measured strength at various temperatures. Synchrotron Micro-XRF analyzed elemental distribution. The materials were mixed and cured at controlled conditions. The compression test provided quantitative strength data. Micro-XRF revealed spatial distribution of elements. The researchers applied heat up to 400 °C and beyond. They compared results to OPC and other geopolymers to assess uniqueness.

The DFA composites reached a maximum strength of 74.48 MPa at optimal conditions. Strength increased with temperature up to 400 °C. Beyond 400 °C, strength continued to rise unexpectedly. Micro-XRF showed homogeneity in elemental distribution up to 400 °C. Higher temperatures further enhanced homogeneity and strength. This behavior contrasts with OPC and other geopolymers. OPC typically maintains or loses strength with heat. DFA composites showed unique thermal resilience. These findings suggest DFA geopolymers could replace OPC in high-temperature applications.

The study found that heat improves DFA geopolymer strength and homogeneity. The maximum strength reached 74.48 MPa at optimal conditions. Elemental distribution remained uniform up to 400 °C. Strength continued to increase beyond 400 °C, unlike OPC. These results suggest DFA composites are suitable for high-temperature environments. The authors propose that DFA geopolymers could replace OPC in construction. They emphasize the need for further testing in real-world applications. The findings highlight a novel property of dolomite/fly ash composites.