Fiber-reinforced concrete (FRC) is widely used in structures subjected to high strain-rate loadings, such as military facilities, earthquake-resistant buildings, hydroelectric dams, and industrial and highway pavements. Despite significant advances in recent decades, certain structural behaviors remain underexplored, particularly when combining…
Fiber-reinforced concrete (FRC) is widely used in structures subjected to high strain-rate loadings, such as military facilities, earthquake-resistant buildings, hydroelectric dams, and industrial and highway pavements. Despite significant advances in recent decades, certain structural behaviors remain underexplored, particularly when combining different concretes, such as thin strengthening layers with distinct characteristics, and incorporating different fibers like strain-hardening cementi- tious composites (SHCC) or even ultra-high-performance concrete (UHPC). Additionally, the appli- cation of carbon textiles in these strengthening layers warrants further investigation. This study aims to evaluate the impact resistance of steel fiber reinforced concrete (SFRC) short beams under flex- ural impact loading, with the addition of SHCC, UHPC, and UHPC layers reinforced with carbon textiles on the tensile face of the beams. The mechanical performance of the composite specimens wasassessed through flexural impact tests at varying energy levels. A custom-built drop-weight test- ing machine, developed at the Structures and Materials Laboratory at PUC-Rio, was used for this purpose. Furthermore, Digital Image Correlation (DIC), in conjunction with high-speed cameras, wasemployedtomeasureenergyabsorption, deformation, and crack propagation in the beams under different configurations and impact energies. The results demonstrated that the SHCC layers sig- nificantly improved energy absorption and reduced crack formation. At the same time, the UHPC composites, particularly those reinforced with carbon textiles, exhibited enhanced ductility, energy absorption capacity, and crack control under impact loading. These findings suggest that the im- proved performance of these composite materials can reduce future repair and reinforcement needs for structures exposed to such demanding conditions. 1 ´ ´ Felipe R. de Souza, Julio J.B.C. Nunes, Victor N. Lima and Flavio A.