Agricultural Waste as Substitute Mixture in Making Cement Hollow Blocks for More Sustainable-Built Environment

Abstract

Hollow cement blocks are commonly utilized in construction due to their benefits; nevertheless, sand demand is increasing due to resource shortages and environmental degradation in the construction industry. In recent investigations, rice husks, egg shells, cow or carabao manure, and coconut shells all exhibit improvements in cement blocks' strength and durability; for this reason, the researchers in this study picked these four components. In addition to addressing the sand shortage and environmental deterioration, this study seeks to ascertain if the selected agricultural wastes can fill gaps in hydration, durability, lightweight, and strength when utilized as coarse and fine aggregates in cement blocks. The experimental research design was suitable for this experimental study. Some tests were conducted, such as compressive strength and weight tests. To determine the difference between standard hollow blocks and the hollow block with substitute aggregates, the ratio 1:2:3 comprised of 50% cement, 20% crushed coconut shells (CCS) as coarse aggregate, and 10% for each of the powdered carabao manure (PCM), pulverized eggshells (PES), and ground rice husks (GRH) for a total of 30% as fine aggregates, and a modified ratio of 1:1:4 of 50% cement, 10% CCS as coarse aggregate, and 15% PCM, 10% PES, and 15% GRH as fine aggregates. The compressive strength test exhibited that the two ratios of hollow blocks made with substitute aggregates performed worse than that of the standard hollow blocks, with 1:2:3 being 51.6% weaker and the modified ratio of 1:1:4 being 26.1%. In terms of weight, however, the two ratios with substitute aggregates had better results, with the ratio of 1:2:3 being 9.7% lighter and the modified ratio of 1:1:4 being 25.8% lighter compared to standard hollow blocks. Based on the tests conducted, the researchers concluded that the weaker compressive strength in hollow blocks made with substitute aggregates is due to the high amounts of silica in the utilized agricultural wastes. As for the decrease in weight of the hollow blocks, this is due to them not having any conventional materials used like sand and gravel, thus decreasing their weight. Furthermore, the amount of CCS as coarse aggregate also contributed to a further decrease in weight in the modified ratio of 1:1:4.