Shear design of steel fiber reinforced concrete beams without stirrups: a parametric analysis

Abstract

Some standards present design recommendations for the shear of fiber reinforced concrete beams, but with there are differences between them. Thus, the aim of this article is to perform the shear design and parametric analysis of beams in steel fiber reinforced concrete (SFRC), without stirrups, based on the methods proposed by the recently released NBR 16935:2021, the FIB Model Code 2010, RILEM TC 162-TDF and the German standard. The study involved a literature review, researching publications of experimental tests involving SFRC beams, with longitudinal reinforcement and without stirrups, aiming to obtain experimental values to compare with the standards’ theoretical predictions of shear capacity. For the parametric analysis, the researchers sought studies with residual tensile strength results based on the EN 14651 test, which is similar to the test recommended by NBR 16935:2021. The parameters that varied were width (b _w ), useful height (d) and longitudinal reinforcement ratio (ρ). The results showed that NBR 16935:2021 and the FIB Model Code 2010 present, on average, characteristic values that are far from the experimental results, being more conservative than the other standards. The longitudinal reinforcement ratio had the greatest influence on the results compared with the other analysed parameters.

Keywords:
Fiber reinforced concrete; Beams without stirrups; Shear capacity; Parametric analysis; NBR 16935