This paper deals with the description, measurement, and use of electromagnetic properties of ferromagnetic fibres used as dispersed fibre reinforcement in composite mixtures. Firstly, the fibres’ magnetic properties are shown, and a method of measuring the hysteresis loop of fibres is proposed. The results from the measurements are presented and a discussion of the influence of measured parameters on the fibres’ orientation in a magnetic field is performed. Furthermore, methods of non-destructive estimation, of their amount and orientation in the composite specimens, are discussed. The main experimental goal of this paper is to show the relationship between this non-destructive method’s results and the destructive flexural strength measurements. The method is sensitive enough to provide information related to fibre reinforcement.

Research presented in this article is aimed to investigate the ability of ultra-high-performance fibre-reinforced concrete to absorb and dissipate mechanical energy at elevated strain rate loading. Specimens made of ultra-high-performance fibre-reinforced concrete were subjected to the low-velocity impact using the new testing procedure where no fixed supports that hold the sample during the impact were applied. The fibre volume fraction of the ultra-high-performance fibre-reinforced concrete was set as the main test variable in the framework of this study and the volumetric fraction of fibres was ranging from 0.125% to 2%. A high-speed camera was used to measure velocities of the impactor and the ultra-high-performance fibre-reinforced concrete specimen before and after the impact. Consequently, the energy dissipated by the ultra-high-performance fibre-reinforced concrete specimen during the impact was calculated using a simple energy balance equation. To determine the basic material properties of ultra-high-performance fibre-reinforced concrete, quasi-static loading rate was applied and conventional methods were used. A significant difference between the values of dissipated energies for different loading rates and various fibre volumetric fractions was observed. It can be noted that the new procedure shows a reasonable approach for testing the fibre-reinforced cementitious composites under localized impact loading and is worthy of further optimization.

In order to achieve better efficiency of dispersed fiber reinforcement in cementitious composites, manufacturers need to be able to directly control the fiber orientation. The magnetic orientation of fibers is an effective way to align fibers in the desired direction of the main tensile stresses and significantly improve the load-bearing capacity of the composite material. In this study, cementitious composites with different percentages of fiber reinforcement were subjected to the magnetic fiber-orienting process and their resulting mechanical parameters were examined. Also, a nondestructive method was used to evaluate the fiber orientation and volume. The flexural strengths and the capacity to dissipate mechanical energy were improved considerably compared to the reference nonoriented specimens. The nondestructive method was also reasonably accurate to predict these results.

This study aims to analyze the performance of laminated glass against ballistic loading and investigates its residual load-bearing capacity. Two groups of specimens were used in quasi-static four-point bending experiments, first without prior ballistic damage and then with it. The main objective was to compare the load-bearing capacity of these two groups to see the effect of ballistic damage. Three different layer compositions were used. The ballistic loading was conducted using an in-service 9 mm bullet fired from a semiautomatic carbine with the glass specimens hanging on steel ropes in a free boundary setup. Numerical simulation and analytical methods were used and validated against the measured response of the undamaged specimens. The simulations were in good agreement with the experimental results. All of the glass specimens were able to withstand the ballistic loading, and the subsequent performance during the quasi-static bending loading was similar to that of the undamaged specimens. The quality of the glass edges seemed to be more important than ballistic damage. The front-plate damage played a negligible role, and the back-plate damage needed to be extensive to influence subsequent performance. Provided that ballistic damage is mainly localized only to the centers of the plates, it did not affect the post-impact loading capacity.