PENGARUH FAKTOR AIR SEMEN TERHADAP KUAT TEKAN DAN POROSITAS BETON PADA VARIAN KOMPOSISI AGREGAT HALUS DAN KASAR UNTUK MUTU BETON K-300

Concrete is a mixture of Portland cement or other hydraulic cement, fine aggregate, coarse aggregate and water, with or without additional ingredients which form a solid mass. The development is currently quite rapid construction and materials used in the work of the many uses of concrete. A large number of concrete use in construction resulted in an increased need for concrete materials, thus triggering rock mining as one of the concrete forming materials on a large scale and the resulting water-resistant concrete, thereby reducing infiltration that led to waterlogging. It can provide an alternative to reduce the material in the concrete itself by not reducing the compressive strength, such as the reduction of fine aggregate concrete. Reduction of fine aggregate on the variant composition of fine and coarse aggregate for concrete quality ratio of the K-300 made of concrete compressive strength and porosity of concrete with each water-cement ratio obtained with normal concrete and concrete variations. For a different variation, the manufacture of sample or specimen was divided into three samples for each concrete mixture with a percentage reduction of fine aggregate and coarse aggregate additions, namely 0% (standard), 5%, 10%, 15%, at 28 days with a compressive strength of 300 Kg/cm2. Water cement factor also varies from 40%, 45%, 50%, 55% and 60%. From the test results on the compressive strength and porosity reduction in sand and concrete to split the addition of as much as 5% to 15%, it can be concluded that the greater the water-cement ratio, the smaller the compressive strength of concrete is obtained. But it is inversely proportional to the porosity of the concrete, the greater the water-cement ratio will get the more pores. Keywords: concrete, reduction of fine aggregate, coarse aggregate addition, water-cement ratio, compressive strength, porosity