Studi Kuat Tekan, Porositas, Dan Permeabilitas Beton Porous Dengan Subtitusi Abu Arang Tempurung Kelapa Terhadap Berat Semen

One of the innovations being carried out in the construction world is nonsand concrete. Non-sand concrete is a type of lightweight concrete that is made without using fine aggregate (sand). The absence of fine aggregate in the mixture results in porous concrete so that the weight is reduced. (Tjokrodimulyo, 2007). In general, coconut shell waste is rarely used by the community so that it is destroyed back to nature without providing economic benefits. This study aims to determine the effect and feasibility of using coconut shell charcoal ash on compressive strength, porosity, and permeability of porous concrete. The mix design used in this study refers to a non-sand concrete book (Trisnoyuwono, 2014) by utilizing the percentage of substitution of coconut shell charcoal ash by 0%, 2.5%, 5%, 7.5%, and 10% by weight of cement , using a total of 30 test specimens with treatment in a soaking tub. Compressive strength, porosity and permeability analyzes were carried out at 28 days. The test specimen has a cylinder dimension of 15 cm x 30 cm. The results of this study indicate the compressive strength for the percentage of coconut shell charcoal ash substitution to 0% cement weight is 5.86 MPa, 2.5% percentage is 4.91 MPa, 5% percentage is 4.54 MPa, percentage 7.5% is 4.07 MPa, the percentage of 10% is 3.79 MPa. So that the porous concrete used in this study meets the compressive strength requirements of porous concrete according to (NRMCA, 2011) and (ACI 522R - 10). As for porosity in the percentage of substitution of coconut shell charcoal ash to cement weight of 0%, 2.5%, 5%, 7.5% and 10% all meet the requirements according to (Trisnoyuwono, 2014). Porous concrete with substitution of coconut shell charcoal ash 0% to the weight of cement meets the permeability requirements based on (NRMCA, 2011) and (ACI 522R - 10), while for the percentage of substitution coconut shell charcoal ash 2.5%, 5%, 7.5% and 10% by weight of cement exceeds the maximum permeability limit. So that the use of coconut shell charcoal ash is not effective as a substitute for the weight of cement because it can reduce the compressive strength, but can increase porosity and permeability