Innovative applications of fibers in concrete: Research and design methods of shear capacity

The aim of the conducted research is to determine the failure model of two-span beams with dispersed reinforcement in the form of steel and basalt fibers. Experimental studies of two-span beams with a cross-section of 120×300 mm and a length of 4150 mm focused on observing changes in the behavior of the tested elements depending on the amount of shear reinforcement and the type of fibers. The beams had varied stirrup spacing. The content of steel fibers was 78.5 kg/m3 [1.0%], and the content of basalt fibers was 5.0 kg/m3 [0.19%]. Concrete beams without fibers were also tested. To assess the impact of the presence of fibers on shear capacity, calculations of the load-bearing capacity of beams with longitudinal reinforcement and dispersed reinforcement in the form of basalt or steel fibers were carried out in accordance with the recommendations of standards PN-EN 1992-1-1 (1), fib Model Code 2010 (2,3), German Committee for Reinforced Concrete DIN 2012 (4), and RILEM TC 162-TDF 2003 (5).