Abstract
This study investigates the effect of a heatโtreatment upon the thermoโmechanical behaviour of a model cementโbased material, i.e. a normalized mortar, with a (w/c) ratio of 0.5. First, a whole set of varied experimental results is provided, in order to either identify or validate a thermoโmechanical constitutive model, presented in the second paper part. Experimental responses of both hydraulic and mechanical behaviour are given after different heating/cooling cycling levels (105, 200, 300, 400^โ^C). The reference state, used for comparison purposes, is taken after mass stabilization at 60^โ^C. Typical uniaxial compression tests are provided, and original triaxial deviatoric compressive test responses are also given. Hydraulic behaviour is identified simultaneously to triaxial deviatoric compressive loading through gas permeability K~gas~ assessment. K~gas~ is well correlated with volumetric strain evolution: gas permeability increases hugely when ฮต~v~ testifies of a dilatant material behaviour, instead of contractile from the test start. Finally, the thermoโmechanical model, based on a thermodynamics approach, is identified using the experimental results on uniaxial and triaxial deviatoric compression. It is also positively validated at residual state for triaxial deviatoric compression, but also by using a different stress path in lateral extension, which is at the origin of noticeable plasticity. Copyright ยฉ 2009 John Wiley & Sons, Ltd.