Utilization of vegetable oil refinery activated carbon-bleaching earth as an additive to the production of low-density facing bricks

Abstract

Incorporating industrial wastes and recyclable materials as additives and/or alternatives in raw materials of concrete bricks is an approach used by environmentalists to convert wastes to reusable materials. Facing bricks are aesthetic material that can be installed in the internal or external walls of houses or buildings. Spent Activated Carbon-Bleaching Earth (SACBE) is an industrial waste generated from the physical refining process of vegetable oil. SACBE is commonly disposed or buried in dedicated landfills. SACBE has no significant utilization and causes environmental hazards upon disposal. The study is designed to find the most effective and efficient mixture ratio of cement facing bricks with SACBE. The paper also investigates the physical and mechanical properties of the SACBE mixture. Three sets of mixtures with varying amount of SACBE in 800 mL, 900 mL, and 1 L of water were created. The volume of sand in the original ratio was substituted with 0% SACBE up to 30% SACBE in increments of 5%. Cement, sand, SACBE, and water were mixed accordingly to the different ratios and air dried in 7 days. Analysis of the results showed that as the percentage of SACBE increases, the density of the facing bricks decreases while the volume of water has no concrete effect on density. The water absorbed in varying amounts of water with the same percentage of SACBE decreased for most samples while the compressive strength is lower for the 900 mL across all samples. Results showed that the 30% SACBE mixture in 1 L of water is the optimum mixture of SACBE. This mixture exhibits higher compressive strength while having lowest density and minimum water absorption compared to other mixtures.