Distributed cracking and stiffness degradation in fabric-cement composites

Abstract

Formation of distributed cracking and the associated degradation in the stiffness of fabric-cement composites under tensile loading were studied. Composites made from low modulus woven polyethylene fabric and bonded Alkali Resistant (AR) glass mesh were manufactured by means of pultrusion technique. The influence of fabric type, matrix modification and curing as well as the pressure applied after pultrusion were studied using tensile stress strain response. Three distinct measures of damage including quantitative crack spacing by image analysis, stiffness degradation, and microstructural observation by optical and scanning electron microscopy are evaluated. The evolution of crack spacing as a function of applied strain was correlated with the tensile response as well as with the stiffness degradation for various composites. Also, the microstructure of the different composites was characterized and correlated with their mechanical properties using optical and scanning electron microscopy. It was observed that the mechanical properties as well as crack spacing and composite stiffness were significantly affected by the matrix formulation, curing procedure, and the intensity of the pressure applied after the pultrusion

Tensile behaviour of mortar-based composites for externally bonded reinforcement systems

“…In glass-aramid composites, e II is between 40% and 50% of the peak strain for G-M and G-P series and about 90% for G-ML and G-L, indicating the predominance of the crack development stage. Conversely, e II is 29% of the peak strain for S4-C, 2% and 5% for S4-ML and S12-C and, finally, not even detectable for S12-ML, in which the contribution of the reinforcement fabric is largely prevalent with respect to that of the matrix, as already found in [30] for TRC.…”

“…15b), which are not directly connected to the matrix. Such telescopic failure is likely to be due to the weaker bond between filaments than that between outer filaments and mortar [30]. Differently, in steel composites, no sliding of the cords within the matrix occurs (Fig.…”

Low velocity flexural impact behavior of AR glass fabric reinforced cement composites

“…The nature of multiple cracking and the resulting stress-strain curve, toughness, and strength, are dependent on the properties of the reinforcing fabrics, the cement matrix, as well as the interface bond and the anchorage of the fabrics developed [15]. Microstructural features such as crack spacing, width, and density allow formulation of the damage evolution as a function of macroscopically applied strain [16,17].…”

Correlation of constitutive response of hybrid textile reinforced concrete from tensile and flexural tests

“…TRC composites utilize innovative fabrics, matrices, and manufacturing processes and have as much as one order of magnitude higher strength, and as much as two orders of magnitude higher in ductility than fiber reinforced concrete [2,3]. Uniaxial tensile strength as high as 25 MPa, and strain capacity of 1-8% are routinely obtained [4,5].…”

“…Uniaxial tensile strength as high as 25 MPa, and strain capacity of 1-8% are routinely obtained [4,5]. A variety of fiber and fabric systems such as alkali resistant glass fibers (G), polypropylene (P), PVA, aramid (A), and carbon (C) have been utilized [2,6,7]. In order to fully utilize these materials.…”