Effects of transient creep strain on post-tensioned concrete slabs in fire

Abstract

Effects of transient creep strain of concrete on post-tensioned (PT) concrete slabs in fire are investigated by the approach of numerical modelling. Three-dimensional (3D) nonlinear finite element (FE) models were established employing the commercial package ABAQUS. Thermal creep strain of prestressing steel tendons was explicitly incorporated into the FE models. Three concrete constitutive models were considered including (a) the Basic Model without considering transient creep strain, (b) the Transient Model explicitly considering transient creep strain, and (c) the EC2 Model implicitly considering transient creep strain taken from BS EN 1992-1-2 (2004). Through comparing the numerical results with those obtained from available tests in the literature, excellent agreement was achieved, based on which the FE model with the Basic Model was verified at ambient temperature, and those with both the EC2 Model and Transient Model were verified as well in test fire scenarios. Conclusions are finally drawn with the emphasis that transient creep strain should be considered either explicitly or implicitly in numerical modelling for its positive contribution to the fire resistance of slabs.