In order to determine the torsional carrying capacity of UHPC beams reinforced with traditional (i.e. longitudinal and transverse) reinforcement in addition to steel fibers, it is essentially important to determine the steel fiber efficiency (i.e. the post cracking tensile strength) in the test beams at the cracking surface at which the failure occurs. Experimental tests on small notched UHPC prisms cast simultaneously with the test beams for torsion in order to determine the steel fiber efficiency showed that the values obtained from these tests may not necessarily reflect the actual fiber efficiency of the torsion test beams at the cracking surface. Experimental tests on notched prisms cut from the torsion test beams at the cracking surface after conducting the torsion tests showed values of fiber efficiency that range between 50 % to 65 % of the values obtained from the first series of tests. The values obtained from the second series of tests were used in an analytical and finite element models to determine the torsional carrying capacity. The comparison between the model predictions and the experimental test results showed very good agreement.
Keywords: UHPC, steel fibers, analytical modeling, torsion, finite element modeling
How to Cite:
Ismail, M. & Fehling, E., (2016) “On the Steel Fiber Efficiency of UHPC Beams subjected to pure Torsion”, International Interactive Symposium on Ultra-High Performance Concrete 1(1). doi: https://doi.org/10.21838/uhpc.2016.23