An Experimental Evaluation Of The Suitability Of Demolished Concrete Aggregate And Ceramic Waste Aggregate As Substitutes For Base Course Material

Abstract

The highway and building industries have recently used an enormous quantity of conventional aggregates each year. Construction costs rise, natural resources are running out, and the condition of the earth's surface is still declining due to the rising demand for conventional aggregaetes, such as ceramic refuse and demolished concrete. However, this is a relatively recent idea that is not well applied in our home nation of Ethiopia. Recycling used construction materials has a number of advantages, including financial efficiency, environmental protection, and the preservation of natural resources. It is crucial to switch to high-quality, accessible, and renewable recycled aggregate materials instead of virgin crushed stone aggregates, especially in developing countries like Ethiopia. The major goal of this study was an experimental evaluation of the appropriateness of demolished concrete aggregate and ceramic waste aggregate as substitute base course material, By using Purposive sampling techniques were used to achieve the goals, and laboratory tests at different replacement percentages of conventional crushed stone aggregate with (0%, 10%, 20%. 30%, 40%, 50%, 100% of demolished concrete aggregate and ceramic waste aggregate weights were conducted. The ceramics were gathered from building construction sites in Jimma City, where demolished concrete had been collected from dumped areas. The standard specification for the ERA pavement design manual and AASHTO T 2 were followed for the sampling and testing procedures for each sample. According to the study's findings, neat CSA and demolished DCA have aggregate crushing values (ACV) of 18.8% and 22.9%, respectively, while blended CSA with 10%, 20%, 30%, 40%, and 50%, of DCA has an ACV of 20.1%, 20.9%, 21.3%, 21.5%, and 21.9%. Similar results were found for Los Angeles abrasion (LAA) (12.55% - 14.99%) and aggregate impact value (AIV) (19.6% - 21.9%). A commercially viable result of 82.6% was discovered at a 40% DCA mix at 98% maximum dry density (MDD) in the CBR test for various ratios of DCA (10% - 50%) combined with CSA. Additionally, the 100% DCA at 98% MDD test result for the California Bearing Ratio (CBR) test was 68.31%. On the other hand, the experimental tests were carried out using various ratios of ceramic waste aggregate (CWA) that satisfy the key mechanical properties of aggregate materials (10%, 20%, 30%, 40%, and 50%). As specified, the blended CWA-CSA aggregate was tested with 10%, 20%, 30%, 40%, and 50% of CWA with its complement of CSA. At 30% CWA replacement of CSA, test results were 22.3% for ACV, 17.01% for LAA, 84.3% for CBR, and 22.2% for AIV. Results that were economically acceptable for this study were attained by satisfying the Ethiopian Road Authority's (ERA) standard specification limit of 30% CWA and 40% DCA combined with CSA for base course construction material.