Influence of Balinese palm fiber and additives on concrete’s compressive and tensile strengths

Abstract Concrete is a material that has an important role in the world of construction. Concrete has high compressive strength but low tensile strength, so this research proposes the addition of Balinese palm fiber and damdex to improve the mechanical properties of the concrete. In this study, Balinese palm fiber was used at 2% of the cement weight with fiber lengths of 1 cm (BS1), 2 cm (BS2), and 3 cm (BS3). Meanwhile, damdex additives are used at 2% of the cement weight. The test object used was a cylinder measuring 15 cm x 30 cm, and the test was carried out at the age of 14 and 28 days with a slump value ranging from 7.5-10 cm. The mixture design was carried out using the SNI 7656:2012 method, where each variation of the mixture was made into 5 test objects, so that in total there were 80 test objects. There are 2 (two) mechanical property tests carried out, namely compressive strength and split tensile strength tests of concrete. From the test results at 28 days, normal concrete (BN) obtained a compressive strength of 29.95 MPa and a split tensile strength of 1.97 MPa. Meanwhile, for each variation, the concrete compressive strength results were 34.48 MPa (BS1), 32.44 MPa (BS2), 31.31 MPa (BS3). Meanwhile, the split tensile strength of concrete is 2.09 MPa (BS1), 2.38 MPa (BS2), and 2.73 MPa (BS3). From the test results it can be seen that adding 2% Balinese palm fiber and damdex gives better results than normal concrete, and provides the benefit of increasing the compressive strength and splitting tensile strength of the concrete.