PENGARUH FIBER LOKAL PADA PERILAKU DAN KUAT TORSI ULTIMIT BALOK BETON BERTULANG (The Effect of Local Fibers on The Behaviour and Ultimit Torsional Strength of Reinforced Concrete Beams)

• المؤلف الرئيسي: Perpustakaan UGM, i-lib
• التنسيق: مقال NonPeerReviewed
• منشور في: [Yogyakarta] : SekolahPascasarjana Universitas GadjahMada 2000
• الموضوعات: Jurnal i-lib UGM
• الوصول للمادة أونلاين: https://repository.ugm.ac.id/24406/; http://i-lib.ugm.ac.id/jurnal/download.php?dataId=7379

ABSTRACT The research was conducted to study the effect of steel fibers on the behaviour and ultimit torsional strength of reinforced concrete beams and prove experimentally that the ultimit torsional strength would increase significantly. The fiber volume fraction added into the concrete mix was 0.6. Uniformly distributed loading of 2,942 N/m2 (300 kg/m2) was applied to the beam, in addition to the torsional moments applied at both ends. Six beam specimens with their dimensions of 100 mm x 200 mm x 2200 mm , three of them were made of fiber concrete (code BF) and the other three were made of normal concrete (code BN), were tested in the laboratory. The concrete mix using ordinary portland cement. The mix proportion of the fiber concrete was cement : sand : agregate ratio of 1 : 1,6 : 2. The water cement ratio was 0.45. The longitudinal steel reinforcement consist of four bars with 10 mm in diameter and closed stirrups (6 mm in diameter) with spacing of 150 mm were used as transverse reinforcement. The beams were supported on special support 1,8 m part, and the torsion load was applied at the both end. The load was applied until the beam ultimit torsional strength was reached. From the observation of the test results, it was concluded that : (1) for relatively high strength concrete (r, = 55 MPa), the increases of tensile and compressive strength due to fiber were not significant, however the ductility was increased significantly, (2) the first crack load and ultimit torsional strength of local fibrous reinforced concrete beams increases 43.02 % and 44.09 %, respectively in comparation with that beams, (3) the strain of the stirrups and longitudinal reinforcements were, respectively, 0.52 and 0.30 times lower than those of the normal concrete beams, and this showed that the local fibers absorbed energy, (4) the pre-crack torsional stiffnes of cross section at a distance d from face of support increases 1.4 times higher than those of the normal concrete beams, (5) the addition of local fibers in the concrete mix reduced the cracking widths. Keywords : beams, cracking, fibers reinforced concrete, torsion, uniform load.