A recent contest of shear tests modelling was carried out in 2019. Teams from universities and consultancies around Europe were invited to predict the shear capacity of two reinforced concrete beams. The basics of the numerical models were to be set up according the Dutch NLFEM Guideline RTD 1016–1:2017. In the contest, two reinforced concrete beams without stirrups but having large depth (1200 mm), tested at Delft University of Technology, were selected as the modelling target. Most participants in the contest did not obtain good agreement with the test results. This paper presents a postdiction study on one of the two tests: H123. Based on this study, some adaptations are made to the recommendations of RTD 1016–1:2017 in order to approach the test results better. The intention of this contribution is to improve the existing NLFEA Guideline for practical engineering structures with uncommon reinforcement layouts.

An experimental program was carried out to investigate the shear capacity of High-Performance Fiber-Reinforced Concrete (HPFRC) I-beams. The main parameters were assigned as the fiber content and presence of shear reinforcement. To study the effect of these main parameters on the shear capacity, testing of six I-beams and other control specimens was conducted. It can be observed from the results of the experimental study that the presence of fibers and shear reinforcement significantly improves the ultimate capacity and structural behavior of HPFRC members. Finally, the experimental results are discussed, and the shear capacity of HPFRC can be estimated by extending the code provisions stated in AFGC-Sétra 2013.

This paper presents a new concept to evaluate the shear capacity of reinforced concrete beams without shear reinforcement having flexural shear failure. Based on experimental observations, it is proposed that the opening of the critical inclined crack can be considered as the lower bound for the shear capacity of a structural member. It is also proposed that the unstable opening of the critical inclined crack is triggered when the shear displacement in an existing flexural crack reaches a critical value Δ_cr. Thus the critical shear displacement is used as a failure criterion, and based on that a new shear evaluation method is proposed. The method shows agreeable accuracy when compared with test results in literature.

This paper presents a new theory for the shear capacity of reinforced concrete members without shear reinforcement. While recognizing that there are multiple failure mechanisms, the theory attributes the opening of a critical flexural shear crack as the lower bound of the shear capacity. It proposes that the shear displacement of an existing flexural crack can be used as the criterion for the unstable opening of the critical flexural shear crack. Based on the theory, the paper presents a simplified shear evaluation model. Compared with the current shear provisions in the design codes, the model is characterized by good accuracy and a solid physical background. It demonstrates a great flexibility for dealing with complex design conditions. As an example, the paper discusses the possibility of extending the theory to the shear resistance of higher-strength concrete. The suggested method provides a more logical and fluent transition from normal- to high-strength concrete and shows good agreement with experimental observations.

The experimental program presented in this paper deals with the influence of the spatial variation of the concrete strength in width direction on the shear capacity of one-way slabs. Two test series are designed, in which the spatial variation of the concrete strength is exaggerated. The influence of the concrete strength variation on the inclined cracking load, failure mode, crack development and other aspects of one-way slabs is examined in the tests.