Shear and Moment Capacities of Steel Fiber Reinforced Concrete Beams
Roop L. Jindal
Appears on pages(s):
beams (supports); fiber reinforced concretes; flexural - - -- metal fibers; moments; shear properties; structural - - structural design.
Tests were made on 44 beams to study the effect of steel fibers as shear reinforcement and to determine if there was any increase in the shear/moment capacity and change in the mode of failure. Span length of 30 in. (762 mm) was used for shear-span ratios (a/d) of 2.0 and 2.4, and 60 in. (1524 mm) for a/d ratios of 3.6 and 4.8. Steel fibers of 1% by volume were used in all SFRC beams. The variables were type of fibers, aspect ratio (l/d) of the fibers and the shear span ratios. Test results showed that shear and moment capacities of SFRC beams varied from 1.50 to 1.92 and 1.12 to 1.39 times, that of conventional reinforced concrete beam, respectively. Pbde of failure changed from shear mode to moment mode when SFRC was used. Steel fibers having aspect ratio of 75 or thin fibers were found to be most effective for increasing the shear capacity of SFRC beams. A design method has been suggested for analysing and designing SFRC beams. Theoretical results based on this method compare favorably with the test results.