Comparison of compressive strength and porosity of porous concrete using the coarse aggregates graded uniform with continuous gradient

Abstract

Porous concrete is a special type of concrete with high porosity. Porous concrete mix consisting of cement, water, and single sized coarse aggregate (graded uniformly). Uniformly graded coarse aggregate difficult to obtain in the market and are usually available are continuously graded coarse aggregate. Compressive strength and porosity are two very important things in porous concrete. Under these conditions, do research that aims to determine the ratio between the compressive strength and porosity of the concrete shaft using coarse aggregate graded uniformly with the use of coarse aggregate graded continuously.Gradation of coarse aggregate (gravel) used in the manufacture of porous concrete in this study there are two types of gradation uniform and continuous gradation. The weight ratio of aggregate / cement used was 4 and 5, and the water-cement factor (FAS) is 0.27. Chemical additives used are SicaCim Concrete Additive at a dose of 7.5 ml / kg cement. The test object in the form of concrete cylinders with a diameter of 15 cm and 30 cm high. Number of test specimens for each variation of a mixture of 3 pieces and the total test object as much as 27 pieces. Treatment is done by soaking the specimen in a tub filled with water. Testing porosity and compressive strength of concrete is done after only 28 days.The study concluded that the larger the maximum size graded gravel uniformly and consistently graded used resulted in the smaller compressive strength and greater porosity. Compressive strength of porous concrete that uses graded aggregate uniformly graded lower than continuous. Compressive strength of porous concrete that uses the highest uniformly graded aggregate amounted to 8.92 MPa and continuous grading is 14.04 MPa. Porosity of porous concrete that uses graded aggregate uniformly graded higher than continuous. Porosity of porous concrete that uses the highest uniformly graded aggregate amounted to 87.68 ltr / dt / m2 and continuous grading of 37.86 liters / sec / m2. Unit weight of porous concrete that uses graded aggregate uniformly graded lower than continuous.