PENGARUH SUBSTITUSI AGREGAT TERHADAP KUAT TEKAN BETON RINGANPENGARUH SUBSTITUSI AGREGAT TERHADAP KUAT TEKAN BETON RINGANPENGARUH SUBSTITUSI AGREGAT TERHADAP KUAT TEKAN BETON RINGAN

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Concrete is a construction material consisting of a mixture of cement, fine aggregate, coarse aggregate and water. Reducing the density of concrete is one of the efforts that can be done to reduce the weight of conventional concrete, one of which is by using pumice to replace crushed stone. Efforts are being made to minimize cracks in the concrete due to the force acting, one of which is by adding fiber to the lightweight concrete mixture. Bamboo fiber as an aggregate will produce concrete that is lighter than concrete using conventional aggregates, which in turn will make the construction lighter. The test aims to determine the effect of the compressive strength of concrete and whether the addition of wet bamboo fiber and dry bamboo fiber in the concrete mixture can produce the planned compressive strength. In this study, using the concrete quality design K-175 with a mixture ratio of 1: 2: 3 and carried out with 3 variations in the percentage of bamboo fiber 2%, 4%, and 6% as a substitute for the weight of pumice. The concrete test object is in the form of a cube with a size of 15 x 15 x 15 cm. The concrete specimens for each variation in the percentage of bamboo fiber were 4 samples with a total of 28 samples, the test was carried out at 28 days of age. From the results of the research conducted, the maximum bulk density was 1639,185 Kg/m3 and the minimum was 1547,259 Kg/m3. In testing the compressive strength of concrete, the maximum compressive strength of 9.072 Mpa is found in 0% bamboo fiber and a minimum of 7.067 Mpa which is found in 6% dry bamboo fiber, in percent the greatest decrease in concrete compressive strength occurs in 0% bamboo fiber to bamboo fiber. dry 6% of 22.17% and the smallest decrease in compressive strength occurred in 0% bamboo fiber to 2% wet bamboo fiber of 8.22%, which indicates that the addition of bamboo fiber experienced a decrease in compressive strength and the planned compressive strength was still in accordance with the planned.

Keywords : compressive strength, lightweight concrete, bamboo fiber, pumice stone, bamboo fiber ratio