Distributed cracking and stiffness degradation in fabric-cement composites

Abstract

� RILEM 2006 Abstract Formation of distributed cracking and the as- sociated degradation in the stiffness of fabric-cement composites under tensile loading were studied. Com- posites 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 pultru- sion were studied using tensile stress strain response. Three distinct measures of damage including quantita- tive crack spacing by image analysis, stiffness degra- dation, and microstructural observation by optical and scanning electron microscopy are evaluated. The evolu- tion 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 charac- terized 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 af- fected by the matrix formulation, curing procedure, and the intensity of the pressure applied after the pultrusion