Sifat Mekanik Kuat Tekan Beton Menggunakan Limbah Beton Sebagai Subtitusi Agregat Kasar

Abstract

Concrete waste from construction activities is often simply discarded without being reused, even though this material still has the potential to replace coarse aggregate in concrete. Efforts to utilize this waste are in line with the concept of sustainable construction that emphasizes the principles of reducing, recycling, and reusing. In this study, concrete waste was utilized as a substitute for coarse aggregate with variations of 25%, 50%, and 75%, and an additive in the form of silica fume was added at 5%. Compressive strength tests were conducted at the ages of 7, 14, and 28 days to meet the development of concrete strength, while slump tests were used to assess workability. The test results showed that the mixture with 50% substitution produced the most optimal compressive strength, namely 25.34 MPa at the age of 28 days. Conversely, at 75% substitution, there was a significant decrease in strength. In addition, the slump value did not decrease linearly with the content of concrete waste—it approached the normal concrete value at 50% substitution before dropping sharply at 75%, indicating reduced workability at higher substitution levels. These findings confirm that the use of concrete waste as coarse aggregate can be an environmentally friendly alternative in industrial construction, with all its compositions being precisely regulated to meet technical standards. Further studies are still needed to explore the use of other additional materials to improve the quality of recycled concrete.