Flexural response of steel-fiber-reinforced concrete beams: Effects of strength, fiber content, and strain-rate

Abstract This study aims to investigate the flexural behavior of steel-fiber-reinforced concrete (SFRC) beams under quasi-static and impact loads. For this, a number of SFRC beams with three different compressive strengths ( f c ' of approximately 49, 90, and 180 MPa) and four different fiber volume contents (vf of 0, 0.5, 1.0, and 2.0%) were fabricated and tested. The quasi-static tests were carried out according to ASTM standards, while the impact tests were performed using a drop-weight impact test machine for two different incident potential energies of 40 and 100 J. For the case of quasi-static load, enhancements in the flexural strength and deflection capacity were obtained by increasing the fiber content and strength, and higher toughness was observed with an increase in the fiber content. For the case of impact load, an increase in the load carrying capacity was obtained by increasing the potential energy and strength, and an improvement in the post-peak behavior was observed by increasing the fiber content. The increases in fiber content and strength also led to enhancements in residual flexural performance after impact damage. Finally, the flexural strength became less sensitive to the strain-rate (or stress-rate) as the strength of concrete increased.

[1]  Andrew S. Whittaker,et al.  Blast testing of ultra-high performance fibre and FRP-retrofitted concrete slabs , 2009 .

[2]  N. Banthia,et al.  Impact resistance of fiber reinforced wet-mix shotcrete Part 2: plate tests , 1999 .

[3]  Ezio Cadoni,et al.  Tensile behaviour of high performance fibre-reinforced cementitious composites at high strain rates , 2012 .

[4]  L. Hsu,et al.  Stress-strain behavior of steel-fiber high-strength concrete under compression , 1994 .

[5]  Nemkumar Banthia,et al.  Polymer and Steel Fiber-Reinforced Cementitious Composites under Impact Loading—Part 2: Flexural Toughness , 2001 .

[6]  S. Shah,et al.  A modified instrumented charpy test for cement-based composites , 1984 .

[7]  Nemkumar Banthia,et al.  Impact resistance of fiber reinforced concrete at subnorma temperatures , 1998 .

[8]  S H Perry,et al.  Impact Behavior of Plain Concrete Loaded in Uniaxial Compression , 1995 .

[9]  Y. Yoon,et al.  Influence of steel fibers and fiber-reinforced polymers on the impact resistance of one-way concrete slabs , 2014 .

[10]  M. C. Nataraja,et al.  STRESS-STRAIN CURVES FOR STEEL-FIBER REINFORCED CONCRETE UNDER COMPRESSION , 1999 .

[11]  P. Land.  Strain rates for three- and four-point flexure tests , 1979 .

[12]  G. Zi,et al.  Effect of shrinkage-reducing admixture on biaxial flexural behavior of ultra-high-performance fiber-reinforced concrete , 2015 .

[13]  Young Soo Yoon,et al.  Response of ultra-high-performance fiber-reinforced concrete beams with continuous steel reinforcement subjected to low-velocity impact loading , 2015 .

[14]  Nemkumar Banthia,et al.  Test Methods for Fexural Toughness Characterization of Fiber Reinforced Concrete: Some Concerns and a Proposition , 1995 .

[15]  Young Soo Yoon,et al.  Local bond-slip response of GFRP rebar in ultra-high-performance fiber-reinforced concrete , 2015 .

[16]  François Toutlemonde,et al.  VISCOUS HARDENING PLASTICITY FOR CONCRETE IN HIGH-RATE DYNAMICS , 1998 .

[17]  Nemkumar Banthia,et al.  Concrete Reinforced with Deformed Steel Fibers, Part I: Bond-Slip Mechanisms , 1994 .

[18]  Surendra P. Shah,et al.  Fiber-Reinforced Cement Composites , 1992 .

[19]  Nemkumar Banthia,et al.  Impact Response of Ultra-High-Strength Fiber-Reinforced Cement Composite , 2002 .

[20]  B. Mobasher,et al.  Low-velocity flexural impact response of fiber-reinforced aerated concrete , 2014 .