PENGARUH PENAMBAHAN SERAT SABUT KELAPA DALAM CAMPURAN BETON TERHADAP KUAT TEKAN DAN MODULUS ELASTISITAS BETON

Abstrak

The rapid advancement of construction technology drives innovation in the use of concrete materials to meet the needs of sustainable development. One such innovation is the incorporation of additional materials into the concrete mix. This research aims to examine the influence of adding coconut fiber as an additive on the compressive strength and modulus of elasticity of concrete. Concrete is a mixture of Portland cement or other hydraulic cements, fine aggregates, coarse aggregates, and water. An experimental method was employed using coconut fiber as an additive to fine aggregates. Tests were conducted on 28-day-old concrete with cylindrical specimens measuring 150 mm in diameter and 300 mm in height. The variations in coconut fiber addition were 0% (normal concrete), 0.125%, 0.25%, 0.35%, and 0.45% of the weight of the fine aggregates. Based on the research findings, the average compressive strength at 28 days for normal concrete was 22.94 MPa. The addition of 0.125% coconut fiber reduced the compressive strength to 19.73 MPa (a decrease of 13.99%), and the addition of 0.35% fiber further reduced it to 18.00 MPa (a decrease of 21.54%). However, the addition of 0.25% fiber increased the compressive strength to 24.38 MPa (an increase of 6.32%), and the addition of 0.45% fiber resulted in the highest increase in compressive strength, reaching 27.28 MPa (an increase of 18.94%). Meanwhile, the average modulus of elasticity for normal concrete was 1663.52 MPa, with a decrease of 92.61%. The addition of 0.125% coconut fiber increased the modulus of elasticity to 2109.63 MPa, but with the addition of 0.25%, 0.35%, and 0.45% fiber, the modulus of elasticity decreased to 1401.09 MPa (a decrease of 93.96%), 782.00 MPa (a decrease of 96.08%), and 634.20 MPa (a decrease of 97.42%), respectively. Thus, it can be concluded that the addition of coconut fiber as a fine aggregate additive impacts the variation in compressive strength and the reduction in the modulus of elasticity of concrete.

Keywords: Concrete, Coconut Fiber, Compressive Strength, Modulus of Elasticity