MODELING TEXTILE REINFORCED CEMENTITIOUS COMPOSITES - EFFECT OF ELEVATED TEMPERATURES

摘要

The textile reinforced cementitious composites (TRC) used in this study are a combination of inorganic phosphate cement (IPC) with a glass fibre chopped strand mat reinforcement. IPC has been developed at the "Vrije Universiteit Brussel". One of the major benefits of IPC compared to other cementitious materials is the non-alkaline environment of IPC after hardening. For this reason, ordinary E-glass fibres are not attacked by the matrix and can be used as reinforcement. By using a fibre volume fraction which exceeds a critical value, the fibres can ensure strength and stiffness at applied loads much higher than the range in which matrix multiple cracking occurs. This results in a strain hardening behaviour in tension. Since the combination of IPC and E-glass fibres leads to a relatively low cost composite, which is entirely made of inorganic materials, it is well suited for utilization in constructions that are exposed to high temperatures. The material itself is characterized by a linear behaviour in compression and a highly nonlinear tensile behaviour. Over the years many efforts have been concentrating on the modelling of this tensile and bending behaviour without taking the effect of temperature loading into account [1][2][3]. This paper presents an analytical and FEM based method in order to model the behaviour of a beam under tension, compression and bending. The analytical model is based on theory of Aveston, Cooper and Kelly (ACK)[4][5][6] and a method proposed by Soranakom and Mobasher. [2] These models will be calibrated by using experimental data from tensile tests. In FEM software (Abaqus) two material models will be evaluated, an elastic-plastic and a hyperelastic "Marlow" model. The effect on the modelling of exposing textile reinforced cementitious composite beams to high temperature (300°C) is included in this paper.