Penggunaan Cangkang Kemiri Sebagai Pengganti Sebagian Agregat Kasar Terhadap Kuat Tekan Dan Kuat Lentur Beton Dengan Zat Tambah Silica Fume

Abstract

The high demand for concrete in construction has increased the need for concrete materials, driving the mining of rocks as a primary component of concrete. Using simple technology that utilizes local resources, including waste as building materials, is essential for concrete technology development. Candlenut shells are a new potential material due to their hard texture. This study uses a design strength of 25 MPa for normal concrete, aiming to observe the effect of using candlenut shells as a partial coarse aggregate replacement with added Silica Fume on concrete's compressive and flexural strength. The mixing method involves replacing coarse aggregate with candlenut shells in 5%, 10%, and 15% proportions. Silica Fume is added at 20% of the cement weight for concrete without candlenut shells and with shell variations at 5%, 10%, and 15%. Results show that adding candlenut shells reduces compressive and flexural strength, but adding Silica Fume enhances both strengths. Notably, the 5% candlenut shell variation with 20% Silica Fume shows higher strength than normal concrete.