Pengaruh Penambahan Fly Ash Terhadap Kuat Tekan Beton K-250 Pada Elemen Struktur Bangunan Bertingkat

Abstract

ABSTRACT

This study is determined to investigate the effect of adding fly ash at 0%, 15%, 20%, and 25% on the slump test, bleeding test, and compressive strength test of K-250 concrete in multi building structural elements. The use of fly ash as a concrete additive has the potential to improve material quality while reducing industrial waste and environmental pollution caused by the accumulation of coal ash from power plants. The research methodology involved analyzing data from normal concrete tests with 0% fly ash content, cured and soaked for 7, 14, 21, and 28 days, with variations in fly ash content of 0%, 15%, 20%, and 25% of the cement weight in the concrete mixture. The research results show that the slump test results with the addition of all fly ash variations meet the requirements, with the lowest slump value of 77 mm at the 20% variation, which provides the best slump with optimal mixture stability. The bleeding test results with the addition of all fly ash mixture variations were below the maximum limit of 10%, thus meeting the concrete quality requirements, with the 0% variation producing the lowest bleeding value, indicating the best concrete density of 0,524%. Regarding the 28-day compressive strength test results, all fly ash mixture variations met the K-250 concrete standard, with the highest increase observed in the 25% variation, where compressive strength reached 279 kg/cm², or an increase of 7.31% from the initial value. The addition of fly ash to concrete demonstrates that this material can enhance concrete quality, making it suitable as an additive for structural elements in multi-story buildings. This finding emphasizes the importance of managing industrial waste from power plants as a strategic step in reducing environmental impact, while also showing that proper utilization of fly ash can contribute to improving concrete quality.

Keywords: Fly ash, Compressive Strength, Slump, Bleeding, Industrial Waste