This paper deals with the optimization of reactive powder concrete mixtures with respect to the addition of silica fume and the type of polycarboxylate superplasticizer used. First, the properties of reactive powder concrete with eight different commercial polycarboxylate superplasticizers were tested in terms of workability, specific weight, and mechanical properties. It was found that different commercially available superplasticizers had significant effects on the slump flow, specific weight, and compressive and flexural strengths. The optimal superplasticizer (BASF ACE430) was selected for further experiments in order to evaluate the influences of silica fume and superplasticizer content on the same material properties. The results showed that the silica fume and superplasticizer content had considerable effects on the mini-cone slump flow value, specific weight, flexural and compressive strengths, and microstructure. There were clearly visible trends and local minima and maxima of the measured properties. The optimal reactive powder concrete mixture had a composition of 3.5–4.0% superplasticizer and 15–25% silica fume.

This study investigates the influence of offset vehicle impacts on the performance of anchored vehicle security barriers using finite element simulations in LS-DYNA. Increasing occurrences of terrorist attacks in public spaces have led to the deployment of both mobile and permanent protective barriers; however, current testing methodologies assume central impacts. The FEM model of an M1 vehicle was coupled with a multifunctional anchored barrier system integrated into urban infrastructure elements. Vehicle impacts at velocities of 15, 50, and 80 km/h were analysed with lateral offsets up to 1000 mm, resulting in 19 configurations for each velocity. The study evaluates barrier effectiveness through analysis of vehicle penetration, crash progression, anchorage response, and force distribution within the anchors, considering both shear and axial loading. The results demonstrate that increasing lateral offset significantly influences barrier response and vehicle penetration, highlighting the importance of considering non-central impacts in future barrier design and standard development.