Novel lightweight Portland Pozzolana cement (PPC) stabilized mud composites using crumb rubber & agricultural waste: physico-mechanical and thermal performance

Abstract

Mud is one of the oldest and most commonly used construction materials on the planet. Mud is used in building construction to provide shelter and as a heat-insulating medium, which is why mud is being used to cover the roofs of buildings in many hot climates. The goal of this experiment was to make Portland Pozzolana Cement (PPC) stabilized mud composites (masonry blocks: 400x200x200 mm and tiles: 300x300x25 mm) using less cohesive soil with the agricultural wastes. It was necessary to add binding material to the mix proportion for manufacturing composites out of earth materials because soil had very low plasticity. In this study, PPC (up to 10%) was used in the mix design along with optimized water binder (w/b) ratios. Each mix proportion was prepared by replacing and adding straw, crumb rubber, and bagasse with soil. In total, 15 different mix-proportions were made. The mix design for making such composites was created by targeting different properties, i.e., thermal conductivity (k)-value, dry density, and compressive strength. After casting, cubes were cured using two methods: water curing and moist curing. It was discovered that wet cured samples outperformed water cured ones. According to the trial results, a 7.5 percent mix proportion of crumb rubber and wheat straw in the soil and cement mix achieved the specified compressive strength of 5.86 MPa. Following that, two model dwellings (LxBxH = 430x510x330 ± 5 mm) were made in order to investigate the heat insulation properties of the composites. Finally, it was found that, with an average temperature differential of roughly 6 °C, the PPC-stabilized mud composite structure was found to be cooler than the typical model home.