PENGARUH CANGKANG KERANG DARA SEBAGAI BAHAN TAMBAH AGREGAT HALUS TERHADAP KUAT TEKAN DAN MODULUS ELASTISITAS BETON (2)

The increasingly advanced era of globalization has led to increasingly rapid developments in construction technology. Developments in construction technology are needed so that the required materials are available easily and quickly. The more concrete technology develops, the more innovation there will be to improve the quality of concrete. One form of innovation is by including some additional materials into the mixture that makes up the concrete. Concrete is a mixture of Portland cement or other hydraulic cement, fine aggregate, coarse aggregate and water as well as concrete additives. This research uses pigeon shells as an added material for fine aggregate by reviewing the compressive strength and modulus of elasticity of concrete. The test was carried out at the age of 28 days, the test object was cylindrical with a diameter of 160 mm x 300 mm with variations of 0% virgin shell (normal concrete) and 2%, 4% and 7% with 5% superplasticizer added (mixed concrete). Based on the research results, it was found that the average compressive strength value at 28 days of normal concrete mix was 16.91 MPa, the addition of 2% virgin shells was 13.26 MPa, the addition of 4% shellfish shells was 15.97 MPa, while the value The average modulus of elasticity in a normal concrete mixture is 22597 Mpa, the concrete mixture with the addition of 2% virgin shells is 18312 Mpa, the concrete mixture with the addition of 4% virgin shells is 19595 Mpa, the concrete mixture with the addition of 7% virgin shells is 20193 Mpa. So it can be concluded that the use of virgin shell waste as an added material for fine aggregate reduces the compressive strength and modulus of elasticity of concrete.