Pengaruh Agregat Kasar Daur Ulang terhadap Workability dan Kuat Tekan Beton Mutu Tinggi

Abstract

Indonesia is a rapidly developing country with a significant amount of ongoing construction projects to meet the growing infrastructure needs of its people. This has led to an increased demand for facilities and spaces for everyday activities. High-quality concrete is widely used, especially in high-rise buildings. Infrastructure development is closely tied to the use of concrete.One of the key components of concrete, namely gravel, is sourced from river stones and natural rocks that tend to deplete over time and are difficult to replace. Therefore, there is a need to explore new alternatives as concrete constituents that can help concrete withstand the pressures and promote environmentally friendly concrete. This can be achieved by utilizing waste from concrete test specimens, which are construction waste or laboratory testing waste that is underutilized.This research examines the impact of using recycled coarse aggregates to replace regular coarse aggregates in high-quality concrete. The research methodology employed is experimental laboratory testing with the goal of understanding the influence of recycled coarse aggregates on the compressive strength of high-quality concrete. Two methods were used in this research: one with superplasticizer to enhance workability in self-compacting concrete (SCC) labeled as BDA and the other without superplasticizer labeled as BDTA. Different percentages of recycled coarse aggregates, selected from 0%, 20%, 40%, 60%, 80%, and 100% of the coarse aggregate's weight, were used to determine the optimal compressive strength at 28 days. The compressive strength tests were conducted using cylindrical test specimens with a diameter of 15 cm and a height of 30 cm at 7, 14, and 28 days. Based on the results of this research, the optimal compressive strength was achieved with the use of superplasticizer and 20% recycled coarse aggregates, with compressive strengths of 35.84 MPa, 41.21 MPa, and 44.01 MPa at 7, 14, and 28 days, respectively. Without superplasticizer, the compressive strengths for 20% recycled coarse aggregates were 26.59 MPa, 35.24 MPa, and 39.11 MPa at 7, 14, and 28 days, respectively. This testing indicates that concrete with 20% recycled coarse aggregates, targeted at a strength of Fc 50, falls within the category of high- quality concrete at 28 days with a compressive strength of 44.01 MPa