STUDI EKSPERIMENTAL PERILAKU MEKANIK BETON NORMAL DENGAN SUBSTITUSI LIMBAH DEBU PENGOLAHAN BAJA (DRY DUST COLLECTOR)

Abstract

Bahan tambah mineral berbutiran halus diperlukan pada beton untuk mencegah terjadinya bleeding dan mengurangi porositas beton. Limbah dry dust collector mempunyai komposisi Fe2O3 = 41,76 %, Al2O3 = 20,05 %, SiO2 = 2,26 %, MgO = 1,66 %, BJ = 3,06 dan tingkat kehalusan 94,25 % lolos ayakan 75 mesh mempunyai potensi untuk digunakan sebagai bahan tambah pada beton. Penelitian ini bertujuan untuk mengetahui perilaku mekanik beton yaitu: kuat tekan, modulus elastisitas, poisson ratio, hubungan tegangan regangan dan kuat lentur serta mencari komposisi optimum substitusi limbah dry dust collector pada campuran beton normal. Program eksperimen dilakukan dengan membuat 9 jenis campuran beton yang berbeda berdasarkan faktor air semen (fas) dan jumlah substitusi limbah pada beton. Komposisi campuran beton yang diteliti adalah beton dengan w/c = 0,68, w/c = 0,57 danw/c = 0,51 dengan substitusi limbah sebesar 0 %, 10 % dan 20 % dari berat pasir. Perilaku mekanik beton diuji pada umur 28 hari. Hasil penelitian diantaranya yaitu : substitusi limbah sebesar 10 % pada beton dengan fas 0,68 dapat meningkatkan perilaku mekanik beton, penambahan limbah pada beton menurunkan nilai slump, pada beton dengan fas 0,68 kadar limbah 10 % kuat tekan beton meningkat sebesar 21,21 %, modulus elastisitas beton naik sebesar 3,69 %, poisson’s ratio sebesar 0,21, kuat lentur beton meningkat sebesar 3,48 % dan regangan beton pada beban puncak naik sebesar 36,96 %. The fine-grained mineral additive material is required in the concrete in order to prevent bleeding and porosity of concrete. The dry dust collector waste has the composition of Fe2O3 = 41.76%, Al2O3 = 20.05%, SiO2 = 2.26%, MgO = 1.66%, specific gravity = 3.06, and refinement rate of 94.25% with sieving pass of 75 mesh and it has a potency to be used as an additive material in concrete. This research has the objectives of finding out an optimum composition of dry dust collector substitution in the normal concrete mixture and finding out the concrete mechanical behavior, which are, compressive strength, elasticity modulus, Poisson’s ratio, stress-strain relation and flexural strength. In this research, 9 different kinds of concrete mixture were created based on the water to cement ration (w/c) and the amount of waste substitution in the concrete. The examined concrete mixture compositions were the concrete with w/c = 0.68, w/c = 0.57, and w/c = 0.51 with the waste substitution as much as 0%, 10%, and 20% of sand weight. The mechanical behavior of the concrete was tested at the age of 28 days. The research results show that, waste substitution as much as 10% in the concrete with w/c of 0.68 can improve concrete mechanical behavior, an addition of waste in the concrete influence concrete workability, in the concrete with w/c of 0.68 and amount of waste as much as 10%, compressive strength of the concrete increases as much as 21.21%, elasticity modulus increases as much as 3.69%, Poisson’s ratio as much as 0.21, flexural strength of the concrete increases as much as 3.48%, and concrete strain at the peak load increases as much as 36.96%.