High-strain rate tension behavior of Fiber-Reinforced Rubberized Concrete

This paper investigates for the first time the high-strain rate splitting tension behavior of Fiber-Reinforced Rubberized Concrete (FRRC). Splitting tension tests were performed on Φ100-mm specimens. Quasi-static tests were carried out using conventional quasi-static loading with a compressive testing machine and dynamic high-strain rate tests with a Φ80-mm Split Hopkinson Pressure Bar (SHPB) for strain rates up to 10s−1. The experimental program comprises the characterization of Plain Concrete (PC), Fiber Reinforced Concrete (FRC), Rubberized Concrete (RuC), and FRRC with a full test matrix (a total of 240 specimens) covering fiber contents up to 1.5% and rubber volume substitution ratios up to 30%. A high-speed camera was used to capture the cracking development processes together with Digital Image Correlation (DIC). The addition of fibers enhances the deformation capacity with a marked increase in the tensile strength both for quasi-static and dynamic conditions while the substitution with rubber aggregates significantly reduces the tensile strength with a similar enhancement of the deformation capacity. For FRRC, a combination of the two effects was observed. FRC, RuC, and FRRC are characterized by marked strain rate dependency within the considered test range. Furthermore, data-driven models for compression and tension strength reduction factor (SRFc and SRFt) and tension Dynamic Increase Factor (DIF) are proposed for different types of FRRC. Finally, a discussion on the image-based damage development processes is provided based on the high-speed camera videos. This study indicates that FRRC has an excellent high-strain rate tension behavior reducing and controlling the crack propagation.