Dynamic Compression Behavior and a Damage Constitutive Model of Steel Fibre Reinforced Self-Compacting Concrete

Liang Bian,Ping Li,Jie Zhang,Jian Ma,José António Fonseca De Oliveira Correia

doi:10.1155/2021/8085949

Abstract

The dynamic behavior of steel fibre reinforced self-compacting concrete (SFRSCC) was investigated by using a split Hopkinson pressure bar (SHPB). SFRSCC specimens with two strength classes of about 40 MPa and 60 MPa were prepared. Different steel fibre volume fractions were used varying from 0.5% to 2.0%. The tested strain rate ranged from about 50 to 240 s−1. Signiﬁcant rate dependence was observed, and dynamic increase factor (DIF) was used to quantify the rate sensitivity. The results showed that both the matrix strength and fibre content had effect on the strain rate sensitivity of SFRSCC. A DIF formula was proposed for describing the dynamic strength of SFRSCC at high strain rates, and a dynamic damage constitutive model was derived to describe the stress-strain relationship of SFRSCC. The parameters in the model were determined by fitting the experimental data. Good consistency between theoretical curves and experimental data was obtained.

Highlights

Concrete structures may be exposed to impact loading conditions during their functional life, such as moving vehicles impacts, violent earthquakes, bomb blasts, and missile attacks [1,2,3]
Significant rate dependence was observed for all types of steel fibre reinforced self-compacting concrete (SFRSCC). e compressive strength increased with strain rate, and the dynamic strength was much higher than the static value. e maximum peak stress achieved in the tests was up to 220 MPa for HC-F1.5, which was more than three times the static strength (64.9 MPa)
For high strength SFRSCC, the dynamic increase factor (DIF) values were close to the CEB-FIP curve in the strain rate range of 50 s−1–240 s−1, as shown in Figure 9, and the strain rate sensitivity was lower than that of medium strength SFRSCC. e DIF values increased with the increase of strain rate, but the strain rate sensitivity tended to decrease when the fibre content was more than 1.5%

Summary

Introduction

Concrete structures may be exposed to impact loading conditions during their functional life, such as moving vehicles impacts, violent earthquakes, bomb blasts, and missile attacks [1,2,3]. Plain concrete exhibits insufficient capacity to resist impact loads due to its low tensile strength and poor resistance to cracking. Adding fibres can improve the energy absorption capacity of the matrix and enhancing the mechanical properties and ductility of concrete [4,5,6]. The most commonly used are the steel fibres which provide reinforcement by bridging the cracks in concrete under various loads. It was found that concrete reinforced with steel fibres showed better impact resistance than other fibres such as polypropylene (PP) fibres or polyethylene (PE) fibres [7, 8]. Steel fibre reinforced concrete is being widely used in civil and military structural applications including road pavements, bridges, channel lining, offshore structures, and military infrastructures [9, 10]

Methods

Results

Conclusion