Pengaruh Limbah Fly Ash pada Sifat Mekanik Beton Mutu Tinggi sebagai Beton Ramah Lingkungan

Abstract

High-quality concrete is characterized by its dense composition with a compressive strength greater than 41.4 MPa. To produce high-quality concrete, a significant amount of cement is typically required. The partial or complete replacement of cement with alternative materials such as fly ash is one of the most viable solutions to create more environmentally friendly concrete with the necessary strength and durability. The aim of this research is to determine the optimum addition of fly ash to produce high-quality concrete. The testing includes compressive strength and split tensile strength. Cylindrical test specimens with dimensions of 15 x 30 cm were used. Additionally, superplasticizer was used as an admixture with the specification viscocrete 8045-P from SIKA. The percentage of fly ash used ranged from 0%, 10%, 20%, 30%, 40%, to 50%, and the superplasticizer dosage was 0.8% of the total cement content plus fly ash. The test specimens were cured in a curing tank using regular water for 28 days. Compressive strength and split tensile strength tests were conducted on specimens at 28 days of age. Based on the research results, it was found that the compressive strength of high-quality concrete decreases with an increasing amount of fly ash added. Adding 10% fly ash to the F'c 60 mix design for high-quality concrete produced the highest compressive strength, with an average compressive strength of 67.151 MPa at 28 days of age. Meanwhile, the lowest compressive strength was observed with 50% fly ash addition, resulting in an average compressive strength of 53.947 MPa at 28 days. Similarly, the split tensile strength of high-quality concrete also decreases with an increasing amount of fly ash added. The highest split tensile strength was achieved with a 10% fly ash addition, resulting in an average split tensile strength of 9.177 MPa at 28 days of age. The lowest split tensile strength was observed with 50% fly ash addition, resulting in an average split tensile strength of 6.801 MPa at 28 days