Previous research on statically loaded reinforced concrete beams has shown a clear influence of the shear span-to-depth ratio on the resulting shear failure mode. Large shear spans relative to the depth typically lead to capacities governed by the breakdown of beam action, whereas low ratios result in capacities governed by the remaining or full arch. Experimental tests with static loading have determined limits for these ratios and the corresponding failure mode. However, no corresponding limits exist for reinforced concrete beams subjected to high strain rates. This is especially true for deep and short beams, for which test data remain scarce. Impact tests were conducted to study shear span-to-depth ratio limits and corresponding shear-type failure modes at high strain rates. Deep, short, and slender beams were tested to study differences in response. Crack development and deformations were analysed using high-speed photography and digital image correlation (DIC). The series consisted of 27 scaled beams tested under static and impact loading, with varying amounts of transverse reinforcement. Results indicated similar shear failure modes for static and impact-loaded beams across the tested shear span-to-depth ratios. For slender beams, inertial forces and undamaged direct struts dominated early, resulting in higher reaction and internal forces for impact-loaded beams. As deformation developed, the response during both load types was similar, with stiffness dominating and flexural and flexural-shear capacities governing the resistance. Strut and tie models generally aligned with the experimental results, while sectional models were over-conservative. A design procedure based on strut and tie modelling was proposed to capture both early transient and quasi-static phase capacities.

Reinforced concrete (RC) is commonly used in defence and protective structures such as shelters and barriers. Such protective structures may be subjected to dynamic loads from explosions from conventional weapons. Protective structures are designed for a ductile response, thereby preventing shear-type failures. The results of this paper are based on experiments conducted on 27 reinforced concrete beams, where 18 were tested dynamically and 9 were tested statically at KTH Royal Institute of Technology. A mass was dropped onto the beams in the dynamic tests, while an MTS machine was used to perform the static tests. The load position was varied at different distances from one of the supports. The beams were designed with both compression and tensile reinforcement and three different configurations of shear reinforcement: no stirrups and stirrups with 90 mm and 45 mm spacing, respectively. The tests were instrumented with load cells and accelerometers. The recorded data were analyzed, focusing on three main factors: the effect of load position, shear reinforcement configuration, and dynamic versus static loading effects. The results indicated that compression strut failures occurred when the load was positioned closest to the support, while the failure mode transitioned to flexural shear with the load further from the support. Beams without shear reinforcement exhibited inclined cracks, with a significant shear influence and less contribution from bending. In contrast, beams with higher shear reinforcement content predominantly developed bending cracks with a diminished influence from shear.  

The infrastructure is in many countries aging and continuous maintenance is required to ensure the safety of the structures. For concrete structures, cracks are a part of the structure's life cycle. However, assessing the structural impact of cracks in reinforced concrete is a complex task. The purpose of this paper is to present a dataset that can be used to verify and compare results of the measured crack propagation in concrete with the well-known Digital Image Correlation (DIC) technique and with Crack Monitoring from Motion (CMfM), a novel photogrammetric algorithm that enables high accurate measurements with a non-fixed camera. Moreover, the data can be used to investigate how existing cracks in reinforced concrete could be implemented in a numerical model.

The first potential area to use this dataset is structural engineering. The data can be used to verify non-linear material models used in a finite element (FE) software to simulate the structural response of reinforced concrete. In particular, the data can be used to investigate how existing cracks should be modelled in a FE model. The second potential area is within image processing techniques with a focus on DIC. Until recently, DIC suffered from one major disadvantage; the camera must be fixed during the entire period of data collection. Naturally, this decreases the flexibility and potential of using DIC outside the laboratory. In a recently published paper [1], an innovative photogrammetric algorithm (CMfM) that enables the use of a moving camera, i.e. a camera that is not fixed during data acquisition, was presented. The imagery of this dataset [2] was used to verify the potential of this algorithm and could be used to validate other approach for non-fixed cameras.

The dataset presented in this paper includes data collected from a three-point bending test performed in a laboratory environment on uncracked and pre-cracked reinforced concrete beams. Structural testing was performed using a displacement-controlled set-up, which continuously recorded the force and the vertical displacement of a centric-placed loading piston. First, the response of three uncracked beams was recorded. Thereafter, photos of the resulting cracks were taken, and a detailed mapping was presented. Material properties for the concrete, e.g., compressive strength, are presented together with testing of the tensile capacity of the reinforcement and a compressive test of the soft fiber boards used at the support to ensure good contact between steel and concrete. Then, the structural response of the pre-cracked beams was tested. During this test, four fixed cameras were used to monitor the crack propagation at different locations on the beam. Images are presented at the start of the load sequences and at pre-defined load stops during the testing. Hence, the crack opening captured in the images can be correlated to the force-displacement data. Moreover, a non-fixed camera was used to capture additional imagery at the location of each fixed camera.