KAPASITAS LENTUR BALOK BETON BERTULANG DENGAN SERAT SABUT KELAPA

Abstract

Concrete has a weakness in its tensile strength and easily broken so that the concrete cross-sectional area of capacity planning appeal is not taken into account. The weakness of concrete can be improved by increasing the fiber that has a purpose as concrete reinforcement fibers uniformly. The fiber used is coco fiber length of 8 cm in the composition of 0%, 1%, 1:33%, 2% and 4% of the volume of concrete. Mechanical changes of concrete obtained from concrete test cylinders and pure bending concrete beams measuring 15 cm x 20 cm x 110 cm at the optimum composition of the fiber to the concrete. The results showed the addition of fiber causes the concrete cylinder press capacity was significantly increased by 5.583% as well as the tensile strength of concrete rose by an average of 5.225%. Ductility properties of concrete increased significantly while the modulus of elasticity of concrete is significantly decreased, the bending capacity of the beam used pure bending optimum composition of 1% of the volume of concrete with fiber deployment 12:25 h and 0.5 h obtained the best results with an average increase of 6.65%.

Beton memiliki kelemahan pada kuat tarik dan sifat getasnya rendah (mudah putus) sehingga dalam perencanaan kapasitas tampang beton daerah tarik tidak diperhitungkan. Kelemahan beton dapat diperbaiki dengan menambah serat yang memiliki tujuan menulangi beton dengan serat secara uniform. Serat yang dipakai adalah serat sabut kelapa panjang 8 cm pada komposisi 0%,1%,1.33%,2% dan 4%  dari volume beton. Perubahan mekanis beton diperoleh dari uji silinder beton dan balok beton lentur murni berukuran 15 cm x 20 cm x 110 cm pada komposisi optimum serat terhadap beton. Hasil penelitian menunjukkan dengan penambahan serat menyebabkan kapasitas tekan silinder beton secara signifikan naik sebesar 5,583%  demikian juga kuat tarik beton naik rata-rata sebesar 5,225%. Sifat daktailitas beton meningkat secara signifikan sedangkan modulus elastisitas beton secara signifikan menurun, kapasitas lentur balok  lentur murni dipakai komposisi optimum 1% serat terhadap volume beton dengan penyebaran 0.25 h dan 0.5 h diperoleh hasil yang paling baik dengan peningkatan rata-rata sebesar 6,65%..