Shear Deformation of Steel Fiber-Reinforced Prestressed Concrete Beams

Abstract

Steel fiber-reinforced prestressed concrete (SFRPSC) members typically have high shear strength and deformation capability, compared to conventional prestressed concrete (PSC) members, due to the resistance provided by steel fibers at the crack surface after the onset of diagonal cracking. In this study, shear tests were conducted on the SFRPSC members with the test variables of concrete compressive strength, fiber volume fraction, and prestressing force level. Their localized behavior around the critical shear cracks was measured by a non-contact image-based displacement measurement system, and thus their shear deformation was thoroughly investigated. The tested SFRPSC members showed higher shear strengths as the concrete compressive strength or the level of prestress increased, and their stiffnesses did not change significantly, even after diagonal cracking due to the resistance of steel fibers. As the level of prestress increased, the shear deformation was contributed by the crack opening displacement more than the slip displacement. In addition, the local displacements around the shear crack progressed toward directions that differ from those expected by the principal strain angles that can be typically obtained from the average strains of the concrete element. Thus, this localized deformation characteristics around the shear cracks should be considered when measuring the local deformation of concrete elements near discrete cracks or when calculating the local stresses.

Pull-Out Behaviour of Hooked End Steel Fibres Embedded in Ultra-high Performance Mortar with Various W/B Ratios

“…The addition of randomised short fibres into mortar has shown to be capable of controlling crack progression as well as resisting tensile stresses (Adjrad et al 2016;Hwang et al 2016;El-Mal et al 2015;Sorensen et al 2014;Islam and Alam 2013a, b;Romualdi et al 1968). The efficiency of fibres in transferring applied stresses is greatly dependent on the fibre-matrix interface properties of fibre reinforced concrete (FRC) (Abdallah et al 2016;Dinh et al 2016;Lu et al 2016;Tadepalli et al 2015).…”

Experimental Study on Shear Capacity of Reinforced Concrete Beams with Corroded Longitudinal Reinforcement

“…As shown in Figure 3a, the specimens were subjected to one-point loading at the center of the span, and the mid-span deflections of the specimens were measured using a linear variable differential transformer (LVDT) installed on the bottom of the section located at the loading point. In addition, an image-based displacement measurement system [23,24] was used to measure the shear strain distribution of the concrete web, as shown in Figure 3b.…”

“…To closely examine the effects of corrosion occurring in longitudinal reinforcement on the shear capacities of RC members, the accelerated corrosion technique was used so as to introduce corrosion into the longitudinal reinforcement without any corrosion of the shear reinforcement. Strain gauges were attached to the shear reinforcements of all specimens to measure the strains of transverse reinforcement, and the shear strain distributions of the concrete web were measured using an image-based displacement measurement system [23,24]. In addition, the crack patterns, failure modes, and shear responses of the specimens were analyzed in detail according to the corrosion rate in longitudinal reinforcement.…”

Characterization of Titanium Nanotube Reinforced Cementitious Composites: Mechanical Properties, Microstructure, and Hydration

“…However, cementitious composites have major drawbacks such as a brittle nature and poor resistance to crack formation under tensile load even though they possess excellent compressive strength. As viable solutions to overcome these problems, reinforcement techniques in the macro-scale using steel reinforcing bars or various fibers (i.e., steel fiber, synthetic fiber, and carbon glass fiber) [2,3,4,5] have been effectively employed in the cementitious materials. The incorporated fibers shared a part of the tensile force applied to the cementitious matrix, and, after crack occurrence, the fibers continuously resisted the tensile force, which contributed to the improvement of tensile strength and strain capacities [6].…”