Compression specific toughness of normal strength steel fiber reinforced concrete (NSSFRC) and high strength steel fiber reinforced concrete (HSSFRC)

Abstract

Compression toughness tests were carried out on concrete cylinders reinforced with three different aspect ratios of hooked-end steel fibers 60, 75, and 83 and six different percentages of steel fibers 0.5, 1.0, 1.25, 1.5, 1.75, and 2.0% by volume of concrete. The w/c ratio used for the normal strength steel fiber reinforced concrete mixes (NSSFRC) was 0.55, and the water-cementitious ratio (w/c+s) for the high strength fiber reinforced concrete mixes (HSSFRC) was 0.31. For each mix, three test cylinders were tested for compression specific toughness. The effect of fiber reinforcement index: volume of fibers × length/diameter ratio on compression specific toughness and also on the relationship between these two properties is presented in this paper. As a result, (a) equations are proposed to quantify the effect of fibers on compression toughness ratio of concrete in terms of FRI, (b) equations obtained in terms of FRI and compression specific toughness of plain concrete to estimate both compression specific toughness of NSSFRC and HSSFRC (N.m), (c) equations obtained which represent the relationship between compression toughness index and FRI for NSSFRC and HSSFRC, respectively, and (d) equations obtained to quantify the relationship between compression specific toughness index and fiber reinforcement index for NSSFRC and HSSFRC, respectively. The proposed equations give good correlation with the experimental values.

Fracture behavior of polymeric fiber reinforced lightweight structural concrete

“…This is attributed to the fact that polypropylene fibers are much less rigid than the cement mortar, which, in an isostrain compressive loading mode, should lead to a degradation of the concrete strength level. More rigid fibers, such as steel for example, are expected, as reported by a number of authors 1,[14][15][16][17] , to enhance the concrete compressive strength. Another important factor that should be taken into account refers to the presence of pores, and hence the higher porosity index associated with the incorporation of polypropylene fibers also contributes to lowering the fiber reinforced concrete strength.…”

High temperature material properties of calcium aluminate cement concrete

“…It is calculated as the area under the stress-strain curve up to specified strain value [43,44]. The energy absorbing capacity of NSC and CACC in compression is recorded up to the peak strain at failure for all the cylinder specimens as observed by Marar et al [45,46]. The performance of CACC and NSC in terms of energy absorbed up to failure in compression for unstressed and unstressed residual test procedure is shown in Fig.…”

A plastic-damage constitutive model for the finite element analysis of fibre reinforced concrete

“…In the present work, the original plasticity model was adopted and modified to account for the changes in the characteristic compressive behaviour that occur with the addition of fibres, in particular steel fibres. Experiments on steel fibre reinforced concrete specimens subjected to uniaxial compression [15,44] indicate several characteristic features such as:…”

“…To reflect this, c c2 is assumed to have the following nonlinear variation with respect to the volume fractions of fibres V f : It is further assumed that the compressive strength (f c ) and the strain at peak stress (ε c ) in Eq. (29) are functions of fibre content and aspect ratio [15,44] …”