Response Characteristics of a Steel Fiber-Reinforced Porosity-Free Concrete Beam Under an Impact Load

Abstract

The utilization of ultra-high-strength concrete offers a weight reduction of concrete structures and improvements in disaster protection performance. Recently, porosity-free concrete (PFC) having the world’s highest compressive strength of 400 MPa has been developed, and its basic mechanical properties were determined; however, its impact-resistant capacity is yet to be examined. In this study, investigation of the impact resistance behavior of PFC is performed using a weight dropping impact test on a fiber-reinforced PFC beam. Steel fiber-reinforced PFC is used for preventing brittle failure, and the full plastic moment of the PFC beam cross-section is determined based on material test results. Also, the estimation of maximum response deflection is attempted by a simple plastic analysis. It was demonstrated that the response deflection could be reduced by 30–50% by increasing the steel fiber mixing rate in the PFC beam from 1 to 2%. The proposed estimation method revealed that the response deflection of the PFC beam could be estimated with an accuracy of approximately 80% considering the calculated full plastic moment when the plastic hinge is clearly formed. In the future, to establish a design procedure for the impact-resistant capacity of protective structures from steel fiber-reinforced PFC, it is necessary to conduct experimental and numerical research focusing on ultimate strength, including statistical processing.