TY - JOUR AU - Altun, F. AU - Haktanir, T. PY - 2004/12/30 Y2 - 2024/03/28 TI - A comparative experimental study of steel fibre-additive reinforced concrete beams JF - Materiales de Construcción JA - Mater. constr. VL - 54 IS - 276 SE - Research Articles DO - 10.3989/mc.2004.v54.i276.252 UR - https://materconstrucc.revistas.csic.es/index.php/materconstrucc/article/view/252 SP - 5-16 AB - Five different batches of class C20 concrete, containing Dramix-RC-80/60-BN steel fibers (SFs) as additives at doses of 0, 30, 40, 50 and 60 kg/m3, and six Ø 15x30 cm prisms were poured from each batch. Standard crushing tests were run on all the specimens and the respective load-displacement and stress-strain curves were plotted. Toughness, ultimate compressive strength and the modulus of elasticity were determined for all specimens. The compressive strength and modulus of elasticity declined in 30 kg/m3 steel-fiber-additive concrete (SFAC) by 9% and 7% compared to the reference C20 concrete without SFs, and the area under the load-deflection curve grew more than twofold. In concrete with a higher SF dosage, the differences in strength and elasticity were around I0% whilst toughness was about the same. Because toughness values were similar in 30, 40, 50 and 60 kg/m3 plain SF-additive concrete and the strength and modulus of elasticity were slightly better in the mixes with the smallest proportion of SF for reasons of economy, 30 kg/m3 was taken as the optimum dose of steel fiber to be added to the reinforced concrete used in a second phase of the study. Hence, of the six reinforced concrete (RC) beams made, all of equal size and with the same under-reinforced tensile reinforcement design, three were made with concrete containing the above-mentioned dose of SF. In addition to compressive strength, these beams were tested for flexural strength, which was found to be 18%) greater for the SFARC beams than the ordinary RC beams, and the upper arms of the load versus mid-span deflection curves prior to ultimate failure of the SFARC beams were considerably longer than the same arms on the curves for ordinary RC beams. ER -