Study on Impact Response of Reactive Powder Concrete Beam and Its Analytical Model

Abstract

The aim of this study was to experimentally examine the impact response of a RPC (Reactive Powder Concrete) beam and develop an analytical model to represent its impact response. Thus, a drop hammer impact test was performed to investigate the influence of drop height of the hammer on the impact response of the RPC beam. Subsequently, a static flexural loading test was conducted to find out the residual load carrying capacity of the RPC beam after impact loading. In the impact analysis, the two degrees of freedom mass-spring-damper system model was used. The analytical results were in good agreement with the experimental results when high damping for the local response at the contact point was assumed.

A Review on Structural Behavior, Design, and Application of Ultra-High-Performance Fiber-Reinforced Concrete

“…A higher ultimate load capacity was also obtained for the beams under impact loading, compared to those under quasi-static loading, and the residual load capacity after impact damage improved by including 2 % steel fibers and using the longer steel fibers. Fujikake et al (2006a) and Yoo et al (2015a) successfully predicted the mid-span deflection versus the time response of structural UHPFRC beams by using the sectional analysis and single-(or multi-) degree-of-freedom model. Improved mechanical compressive and tensile strengths according to the strain-rate were considered in the analysis by using the equations for the dynamic increase factor (DIF) of the UHPFRC, as suggested by Fujikake et al (2006bFujikake et al ( , 2008.…”

“…The initial stiffness in the UHPFRC beams was insignificantly affected by the impact damage because of the excellent fiber bridging capacities after matrix cracking, and the residual load-deflection (or moment-curvature) curves, shifted based on the maximum deflection by impact, exhibited quite similar behaviors with those of the virgin specimens without impact damage. Hence, Fujikake et al (2006a) mentioned that the maximum deflection response can be used as the most rational index for estimating the overall flexural damage of reinforced UHPFRC beams. Yoo et al (2015a) reported that better impact resistance, i.e., lower maximum and residual deflections and higher deflection recovery, was obtained by increasing the amount of longitudinal steel rebars, and the maximum and residual deflections of reinforced UHPFRC beams decreased significantly by adding 2 % (by volume) of steel fibers, leading to a change in the damage level from severe to moderate, whereas slight decreases in the maximum and residual deflections were found by increasing the fiber length at identical volume fractions (Yoo et al 2015c).…”

“…However, based on the suggested material models in Fig. 14, the design of a UHPFRC element subjected to bending can be performed by using the sectional analysis (Fujikake et al 2006a;Yang et al 2011;Ferrier et al 2015;Yoo and Yoon 2015;Yoo et al 2016). A schematic description of a multi-layered cross-section with strain and stress distributions and an algorithm for sectional analysis are shown in Fig.…”

“…The use of longitudinal reinforcements and stirrups also obviously improved the torsional performance. 3.5 Performance of Structural UHPFRC Beams, Slabs, and Columns Under Extreme Loadings Fujikake et al (2006a) and Yoo et al (2015a, c) examined the impact resistance of reinforced or prestressed UHPFRC beams by testing a number of specimens using a drop-weight impact test machine. In their studies (Fujikake et al 2006a), an increase in the maximum deflection of UHPFRC beams was observed by increasing the drop height while maintaining the weight of the hammer, owing to the increase of kinetic energy.…”

“…3.5 Performance of Structural UHPFRC Beams, Slabs, and Columns Under Extreme Loadings Fujikake et al (2006a) and Yoo et al (2015a, c) examined the impact resistance of reinforced or prestressed UHPFRC beams by testing a number of specimens using a drop-weight impact test machine. In their studies (Fujikake et al 2006a), an increase in the maximum deflection of UHPFRC beams was observed by increasing the drop height while maintaining the weight of the hammer, owing to the increase of kinetic energy. The initial stiffness in the UHPFRC beams was insignificantly affected by the impact damage because of the excellent fiber bridging capacities after matrix cracking, and the residual load-deflection (or moment-curvature) curves, shifted based on the maximum deflection by impact, exhibited quite similar behaviors with those of the virgin specimens without impact damage.…”