Analisa Kuat Tekan Beton Normal Menggunakan Cangkang Biji Karet

Abstract

Concrete is a mixture of cement, aggregates, and water, with or without additional materials, to form a solid, string, and stable mass. It is widely used in construction due to its availability, moldability, strength, durability, and low maintenance. Concrete’s compressive strength depends on the correct mix composition ration, and one way to modify its properties is by using admixtures. This study investigates the effects of rubber seed shell ash on an alternative admixture on concrete. A quantitative experimental method was used to assess the impact of adding rubber seed shell ash on the specific gravity and compressive strength of concrete. Four variations were tested: 0%, 3%, 6%, and 9% of the total cement weight. The specimens were cylindrical, with a diameter of 15 cm and a height of 30 cm, and underwent compressive strength test at 7, 14, and 28 days using the water curing method. The results showed a decrease in specific gravity with increasing ash content, with average weights of 2251,31 kg/m3, 2224,89 kg/m3, 2213,04 kg/m3, and 2207,19 kg/m3, respectively. However, the compressive strength also decreased with higher ash content. At 28 days, the compressive strengths were 18,023 MPa (0% ash), 13,305 MPa (3% ash), 11,805 MPa (6% ash), and 11,607 MPa (9% ash). Therefore, while rubber seed shell ash reduces specific gravity, it doses not enhance compressive strength, suggesting limited use in applications requiring high strength, further research could explore combinations with other materials to improve its effectiveness.