Mechanical Property Comparison of Geopolymer Brick Dried by Electrical and Passive Solar Devices with Phase Change Material (Paraffin Wax)

Abstract

In geopolymer bricks (GPBs), fly ash content, which is waste from power plants, is converted into bricks by chemical treatment. GPBs can be dried by using appropriate curing methods. Conventionally, electric oven curing is one of the prominent methods. Using a solar dryer instead of an electric oven provides the added advantage of saving high-grade electrical energy. So, in this work, a solar dryer with the phase change material (PCM) paraffin wax and without a PCM is used for curing applications. GPBs gain an added advantage when compared to conventional bricks like cement and sand bricks in terms of strength. A GPB has been taken as a specimen for comparing the compressive strength, tensile split strength, and flexural strength of electrical-energy-based curing and solar-energy-based curing. It has been experimentally observed that solar-energy-based curing with and without a PCM exhibits higher compressive strength, higher tensile split strength, and flexural strength when compared to electrical-energy-based curing. Solar curing with a PCM shows higher compressive strength, higher tensile split strength, and higher flexural strength when compared to solar curing without a PCM. Open solar curing is a traditional technique, but nowadays, aggressive climatic conditions can lead to severe damage to geopolymers. The novelty of this work is the study of the effect of PCMs like paraffin wax in solar drying on the curing time and the mechanical properties of GPBs.