Direct assessment of tensile stress-crack opening behavior of Strain Hardening Cementitious Composites (SHCC)

Abstract

The process of designing Strain Hardening Cementitious Composites (SHCC) is driven by the need to achieve certain performance parameters in tension. These are typically the pseudo-strain hardening behavior and the ability to develop multiple cracks. The assessment of the tensile load-deformation of these materials is therefore of great importance and is frequently carried out by characterizing the material tensile stress-strain behavior. In this paper an alternative approach to evaluate the tensile performance of SHCC is investigated. The behavior of the material in tension is studied at the level of a single crack and the tensile performance is evaluated in terms of the tensile stress-crack opening behavior. The experimental procedure and test setup used are discussed. The derived tensile stress-crack opening behavior is utilized to analyze and compare the influence of various composite parameters on the resulting tensile behavior. The deformations occurring during tensile

A model to simulate the moment–rotation and crack width of FRC members reinforced with longitudinal bars

“…The shape of the r-w diagram can be determined by performing uniaxial tensile tests with notched FRC specimens [15,16], or by inverse analysis by fitting with a target accuracy the force-crack mouth opening displacement (CMOD) registered in notched FRC beam bending tests [15,17]. Available experimental and numerical research evidence that a r-w diagram formed by four branches is capable of simulating with enough accuracy the post cracking behavior of the types of FRC being used in structural applications [13].…”

Particle image velocimetry (PIV) to evaluate fresh and hardened state properties of self compacting fiber-reinforced cementitious composites (SC-FRCCs)

“…Detection of cracks with non-contact measurement techniques, such as analyzing images of concrete surfaces has been explored by many researchers [13][14][15][16] using a variety of methods. Some of these image based methods are, Digital Image Correlation (DIC), photogrammetry and video extensometers.…”

Cracking and load-deformation behavior of fiber reinforced concrete: Influence of testing method

“…To isolate a single crack and to avoid multiple cracking, an alternative test method for tension softening as well as strain hardening FRC was developed by Pereira et.al. [2], where the formation of a single, localized crack was consistently verified and a relationship between applied tensile load and crack opening was established.…”

“…The first cracking strength of ECC is smaller (2.5 -3.4 MPa) than the maximum stress that fibers can bridge across the crack (3.4 -4.4 MPa). As the first cracking strength is lower than the ultimate stress that the fibers can carry over the crack, the multiple cracking and strain hardening behaviors under uni-axial tension in the un-notched ECC material can occur [2,23]. The ultimate stress that the fibers can carry over the crack can correspond to the smallest value of the sum of pullout strength of all fibers in the cross section or fiber rupture strength, depending on the actual material.…”

“…In the first group of test methods, the single-crack notched [2] coupon test and the dog-bone test [3,4] are intended to determine the local and global tensile behavior of a FRCC material with special emphasis on strain-hardening materials. In the second group of tests, among many different beam types and loading configurations, the most common are the three or four-point bending test, with or without notch.…”