Evaluation of Crack Propagation and Post-cracking Hinge-type Behavior in the Flexural Response of Steel Fiber Reinforced Concrete

Abstract

An experimental evaluation of crack propagation and post-cracking behavior in steel fiber reinforced concrete (SFRC) beams, using full-field displacements obtained from the digital image correlation technique is presented. Surface displacements and strains during the fracture test of notched SFRC beams with volume fractions (V f ) of steel fibers equal to 0.5 and 0.75% are analyzed. An analysis procedure for determining the crack opening width over the depth of the beam during crack propagation in the flexure test is presented. The crack opening width is established as a function of the crack tip opening displacement and the residual flexural strength of SFRC beams. The softening in the post-peak load response is associated with the rapid surface crack propagation for small increases in crack tip opening displacement. The load recovery in the flexural response of SFRC is associated with a hinge-type behavior in the beam. For the stress gradient produced by flexure, the hinge is established before load recovery is initiated. The resistance provided by the fibers to the opening of the hinge produces the load recovery in the flexural response.

Probabilistic Analysis for Strain-Hardening Behavior of High-Performance Fiber-Reinforced Concrete

“…Typically, concrete under tension exhibits brittle failure with initial cracking when there is no reinforcement. In an effort to improve the post-cracking tensile behavior, many researchers have investigated fiber-reinforced concrete that exhibits post-cracking tensile behavior by adding fiber into the concrete mixture, and as a result, increases ductility of concrete after the crack formation [2,3,4,5,6,7,8,9,10]. Lee et al [2] developed an analysis procedure for steel-fiber-reinforced concrete (SFRC) elements subjected to shear by implementing constitutive models which are derived from the diverse embedment model (DEM).…”

“…Li et al [4] investigated shear performance of SFRC beams without web reinforcement. Gali and Subramaniam as well as Husain et al [5,6] evaluated the improved ductile responses of SFRC beams and flat slabs, respectively. The cyclic response of SFRC slender beams was investigated by Chalioris et al [7].…”

Pukotine od savijanja u gredama od betona ojačanog vlaknima s armaturnim šipkama od vlaknima ojačanog polimera

“…The approximation happens only in the pre-cracking phase, while in the following phases it differs from reference values. An increase in fibre ratio affects the pre-cracking behavior but the ratio taken for this experiment did not achieve the nominal fibre content in order to influence the post-cracking behaviour [19]. Adding small fraction of fibres did not influence the post-crack behavior.…”

Crack Detection and Localisation in Steel-Fibre-Reinforced Self-Compacting Concrete Using Triaxial Accelerometers

“…However, fibres in SCC offer beneficial improvements in terms of ductility, toughness, and energy absorption capacity [ 16 , 17 , 18 ]. Fibres also control the crack propagation in concrete, contributing to better post-cracking behaviour [ 16 , 19 ]. In some specific applications, fibres can partially or completely replace conventional reinforcement [ 20 ].…”