Dynamic Properties of Strain-Hardening Cementitious Composite Reinforced with Basalt and Steel Fibers

Na Zhang,Guo-Wei Ma,Jian Zhou

doi:10.1186/s40069-020-00415-y

Abstract

Strain-hardening cementitious composites (SHCCs) reinforced with both basalt and steel fibers are expected to possess the advantages of both fiber materials and exhibit desirable mechanical properties. In this study, we experimentally investigated the dynamic mechanical properties of an SHCC reinforced with inorganic fibers of basalt and steel for different strain rates (101 to 102 s−1) using a 50-mm-diameter Split-Hopkinson pressure bar. The effects of the strain rate on the dynamic compressive strength and dynamic splitting strength as well as the dynamic increase factor and energy absorption characteristics of the SHCC were analyzed. The results showed that all the mechanical indices increased with an increase in the strain rate. The dynamic increase factors of the compressive strength and splitting strength increased linearly with the decimal logarithm of the strain rate. Further, the addition of the basalt and steel fibers resulted in a significant increase in the strain-rate sensitivity of the dynamic mechanical behavior of the SHCC, with the effect of the steel fibers being more pronounced than that of the basalt fibers. Although the basalt and steel fibers had varying effects on the strain-rate sensitivity of the dynamic mechanical behavior of the SHCC based on the fiber content, there were significant positive correlations between the type and content of the fibers used and the strain-rate sensitivity.

Highlights

Cementitious materials are inherently brittle and easy to crack and exhibit poor mechanical properties and long-term durability problems
It can be seen that the specimens with the basalt fibers (BFs) and steel fibers (SFs) fibers exhibited different strain-hardening behaviors from those of engineered cementitious composites (ECCs) with polyvinyl alcohol (PVA), PE, or PP fibers
It has been reported that, in the case of composites with PVA-SF fibers, the dynamic compressive strength increases with the SF content (Li et al 2016)

Summary

Introduction

Cementitious materials are inherently brittle and easy to crack and exhibit poor mechanical properties and long-term durability problems. (2005) concluded that ECCs with steel and polyethylene (PE) fibers show higher tensile strength as the strain rate is increased. Soe et al (2013) studied the dynamic tensile properties of hybrid fiber ECCs for increasing strain rates (from 10−5 to 10−1 s−1). Compared with an ECC reinforced only with PE fibers, an ECC reinforced with both PE and steel fibers showed higher tensile strength and tensile strain capacity. Li et al (2016) concluded that the addition of steel fibers improves the dynamic behavior of ultrahigh-toughness cementitious composites, even when the volume content of polyvinyl alcohol (PVA) fibers is kept constant at 2%. The static and dynamic mechanical properties of concrete reinforced with basalt fibers (BFs) and PP fibers have been studied (Fu et al 2018; Wang et al 2019). It was found the combined use of both BFs and PP fibers is effective in enhancing the mechanical properties of concrete

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