An Experimental Study on the Compressive Dynamic Performance of Polypropylene Fiber Reinforced Concrete for Retaining Structure under Automobile Collision Magnitude

Furong Li,Guoxing Chen,Guizhong Xu,Yongyi Wu

doi:10.1155/2020/8826006

Abstract

In order to examine the compressive dynamic performance of polypropylene fiber reinforced concrete to be used for the retaining structure under the automobile collision magnitude, an experimental study was carried out by using hydraulic servo on concrete specimens with 4 different polypropylene fiber contents under 6 loading strain rates. The failure modes and stress-strain curves of concrete under different loading conditions were obtained. Then, by comparatively analyzing the mechanical characteristic parameters of polypropylene fiber reinforced concrete under different loading conditions, the following conclusions are drawn: with the increase of the polypropylene fiber content, the integrity of concrete upon compressive failure is gradually improved. When the polypropylene fiber content is relatively high, the static and dynamic failure modes are basically similar. With the increase of the loading strain rate, the peak compressive stress and elastic modulus of the polypropylene fiber reinforced concrete gradually increase. The increase in the polypropylene fiber content gradually intensifies the effect of loading strain rate on the peak compressive stress dynamic improvement coefficient. The peak strain of polypropylene fiber reinforced concrete is gradually increased with the increase of polypropylene fiber content, while the effect of the loading strain rate on the peak strain shows an obvious discreteness characteristic. Meanwhile, we proposed a relationship equation for describing the peak compressive stress dynamic improvement coefficient based on the coupling effect of the polypropylene fiber content and loading strain rate and further discussed the underlying stress mechanism in detail. Our research findings are of important research significance for the application and promotion of polypropylene fiber reinforced concrete in the engineering practice of retaining structures.

Highlights

Polypropylene fiber reinforced concrete is a kind of concrete material formed by adding polypropylene fiber into ordinary concrete in accordance with a certain proportion
In accordance with the research on the influence of polypropylene fiber content on the strength eigenvalue of concrete, it was found that the compressive strength, tensile strength, and flexural strength of concrete gradually increased with the increase of the fiber content within a reasonable range; when the fiber content exceeded a certain proportion, the concrete strength would decrease to a certain extent [16,17,18]
In accordance with our analysis on the influence of the polypropylene fiber content and loading strain rate on the compressive dynamic performance of concrete, the following conclusions are drawn: (1) For the same loading strain rate, the concrete with higher polypropylene fiber content remains a better integrity upon compressive failure

Summary

Introduction

Polypropylene fiber reinforced concrete is a kind of concrete material formed by adding polypropylene fiber into ordinary concrete in accordance with a certain proportion. Zhang [25] investigated the dynamic performance of high-content polypropylene fiber reinforced concrete by applying SHPB and concluded that the polypropylene fiber could gradually increase the strain of concrete, which might play a certain role of crack resistance and energy dissipation, but could not improve the compressive strength dynamic improvement coefficient of concrete. A comprehensive study on the dynamic performance of polypropylene fiber reinforced concrete under the effect of medium-low strain rates is of great significance to an in-depth understanding of the safety performance of polypropylene fiber reinforced concrete structures under the magnitude of automobile collision and earthquake. We carried out an experimental study on the effect of strain rates at the automobile collision magnitude on the compressive dynamic performance of retaining structures that were made of concrete reinforced with different contents of polypropylene fiber. En, by comparatively examining the mechanical performance characteristic parameters under different loading conditions, we comprehensively analyzed the compressive dynamic performance of the polypropylene fiber reinforced concrete from both qualitative and quantitative perspectives and investigated the corresponding stress mechanism in detail

Experiment Overview

Analysis of Experimental Results

Eigenvalues of Mechanical Parameters

Findings

Conclusions