This study examines the behaviour of reinforced concrete (RC) slabs subjected to contact explosions through experimental investigations and numerical simulations. A contact explosive charge field experiment was conducted on a bi-directionally reinforced RC slab to characterise the resulting damage patterns. The experimental findings revealed localised perforation and substantial deformation of the reinforcement bars without bar rupture. A numerical model employing the RHT concrete and Johnson–Cook steel material models was implemented in Ansys Autodyn (v 2023 R2) to replicate the observed responses. Initial verification was carried out against data from the literature, and calibration was performed using the instantaneous geometric strain (IGS) as the erosion parameter. An optimal IGS value of 0.375 was found to reproduce the experimental damage most accurately. Subsequent parametric analyses of the validated models investigated the influence of slab thickness and reinforcement ratios on blast resistance. The results demonstrated that increasing the slab thickness substantially mitigates perforation, while higher reinforcement ratios improve overall structural integrity. This work confirms the reliability of the calibrated numerical models for predicting the response of RC slabs to contact explosions, and it offers valuable insight into the design of blast-resistant structures.

Environmental and urbanisation challenges have encouraged steady growth of mass timber structures where cross laminated timber (CLT) stands out in applications as full-size wall, floor, or beam elements. Beam elements are used mainly in situations where cross layers have a reinforcing effect on the tensile stress perpendicular to the beam axis, such as when introducing holes or notches, which is common practice in beams, due to engineering, installation, or architectural requirements. This paper presents experimental investigations of CLT beams with holes or notches for comparison and validation of an analytical model provided in the literature. Different sizes of holes and notches as well as different placements of the holes were considered in the experiments. All relevant failure modes were analysed and discussed in detail. Two predominant failure modes were indicated, i.e., bending failure and shear failure in crossing areas (mode III). Results further indicate that reduced lamination widths near the hole, notch, or element edges have a relatively small influence on the beam strength. Parametric studies indicate net shear failure (mode II) and tensile failure perpendicular to the beam axis as the critical failure modes in most of the considered cases, indicating their strong underestimation in design verifications according to the analytical model.