Pengaruh Penambahan Kulit Kerang Sebagai Pengganti Sebagian Agregat Halus dan Penambahan Gula Pasir Sebagai Alternatif Zat Additive Terhadap Kuat Tekan Dan Kuat Lentur Beton

The use of shellfish waste as a substitute for some of the fine aggregate can increase the compressive strength value of concrete at a certain level of variation, however, in the processing of shellfish waste absorbs water so that it reduces the slump value and affects the ease of casting, so it requires added sugar as an alternative to additive retarder. Because in general, basic ingredients that contain sugar can be used as a retarder. This study aims to determine the effect of the addition of shellfish waste and sugar on the compressive strength and flexural strength of concrete, to compare the initial binding time (setting time) and slump value, and to determine the strength ratio of normal concrete with concrete mixed with shellfish waste and sugar. This study used concrete samples in the form of cylinders and blocks, the samples were made of 12 cylinders and 12 blocks. This study used an experimental method, namely combining waste shells and sugar into a concrete mixture with the percentage of shellfish waste used was 10% of fine aggregate and sugar as much as 0.05%; 0.1%; 0.15% by weight of cement. Concrete mix design refers to SNI 03-2834-2000. The compressive strength and flexural strength test were analyzed at the age of 28 days. The results of this study indicate that the use of shellfish waste and sugar can increase the compressive strength of the concrete cylinder at a variation of 10% seashell waste + 0.05% and 0.1% sugar, while the flexural strength value is below the normal concrete flexural strength. . The result of the maximum compressive strength of concrete is the variation of 10% shellfish waste + 0.05% sugar at 31.407 MPa. The use of sugar greatly affects the setting time and slump value, the higher the sugar content based on the variations used, the longer the initial setting time and the higher the slump value obtained. With the use of sugar which can prolong the initial binding time, it can be utilized if the project location is far from the batching plant. The use of variations of the mixture of shells and sugar can be used in the construction of structures with medium quality (30-40 MPa)