Even though the structural behavior steel fiber reinforced concrete (SFRC) has been extensively researched, structural applications are still limited. One barrier to its implementation is the lack of mechanical models that describe the behaviour of SFRC members failing in shear. This paper reviews the effect of steel fibers on the different mechanisms of shear transfer and combines the observations from the literature regarding the parameters that affect the shear capacity of SFRC.Additionally, a selection of currently available expressions for the shear capacity of SFRC is presented. This paper reviews the current state-of-the-art on the shear capacity of SFRC elements without shear reinforcement, shows the lacks in our current understanding on the shear behaviour of SFRC elements without shear reinforcement, and outlines the steps necessary to address these lacks. The presented work aims to be a framework for (experimental) efforts addressing the shear capacity of SFRC members without shear reinforcement.

Adding steel fibers to concrete improves the capacity in tension-driven failure modes. An example is the shear capacity in steel fiber reinforced concrete (SFRC) beams with longitudinal reinforcement and without shear reinforcement. Since no mechanical models exist that can fully describe the behavior of SFRC beams without shear reinforcement failing in shear, a number of empirical equations have been suggested in the past. This paper compiles the existing empirical equations and code provisions for the prediction of the shear capacity of SFRC beams failing in shear as well as a database of 488 experiments reported in the literature. The experimental shear capacities from the database are then compared to the prediction equations. This comparison shows a large scatter on the ratio of experimental to predicted values. The practice of defining the tensile strength of SFRC based on different experiments internationally makes the comparison difficult. For design purposes, the code prediction methods based on the Eurocode shear expression provide reasonable results (with coefficients of variation on the ratio tested/predicted shear capacities of 27–29%). None of the currently available methods properly describe the behavior of SFRC beams failing in shear. As such, this work shows the need for studies that address the different shear-carrying mechanisms in SFRC and its crack kinematics.

Upon assessment of existing reinforced concrete short-span solid slab bridges according to the recently implemented Eurocodes that include more conservative shear capacity provisions and heavier axle loads, a number of these structures were found to be shear-critical. The results from recent experimental research on the shear capacity of slabs indicate that slabs benefit from transverse load distribution. Recommendations for the assessment of solid slab bridges in shear are developed on the basis of these experiments. A load spreading method for the concentrated loads is proposed and the applicability of superposition of loading is studied. The resulting most unfavourable position for the design trucks is provided and implemented in the so-called Dutch "Quick Scan" method (QS-EC2). Cases of existing bridges are studied with the previously used QS-VBC as well as with the QS-EC2 that includes the recommendations. As a result of the assumed transverse load distribution, the shear stress to be considered at the support based on the recommendations becomes smaller.Keywords: effective width; live loads; load distribution; reinforced concrete; slab bridges; shear.The shear capacity as prescribed by NEN 6720 3 and NEN-EN 1992-1-1 2 is determined from a statistical analysis of experiments on relatively small, heavily reinforced concrete beams loaded in four-point bending.6 When these expressions are applied to determine the shear capacity of a slab under a concentrated load, the contribution of the surrounding material, which is activated through transverse load distribution, is not taken into account. Moreover, the effective width in shear for slabs under a concentrated load needs to be determined. In practice, the effective width is based on a load spreading method:1. from the centre of the load towards the face of the support as used in Dutch practice (Fig. 1a), resulting in b eff1 ; or 2. from the far side of the load towards the face of the support as used in French practice 7 (Fig. 1b), resulting in b eff2 .To quantify the enhancement due to transverse load distribution in slabs under a concentrated load in shear, a comprehensive series of experiments was carried out. [8][9][10] In a first series of experiments, 18 slabs and 12 slab strips were tested under a concentrated load near the support. In a second series, eight additional slabs were tested under a combination of a concentrated load near the support and a line load. These experiments form the basis for new recommendations for the shear assessment of slab bridges. In sections Experiments and Recommendations, the link between these experiments and the recommendations is discussed.The large number of solid slab bridges that are identified as shear-critical require a systematic approach. In a preliminary general assessment, the database of slab bridges was screened in order to identify the particular bridges that require a more detailed analysis. For this purpose, a fast, simple and conservative tool is required: the "Quick Scan" method (QS-EC2). The fi...