Delayed ettringite formation (DEF) is a pathology that induces concrete swelling and cracking. Factors contributing to DEF have been identified experimentally, but on the modelling side the link between DEF-inducedexpansionandtheevolutionofconcreteandmortarphysicalproperties hasbeenlessstudied. Amulti-scaleporomechanicalmodelisintroducedwhichfeaturesadescription of DEF induced mortar damage by progression of…
Delayed ettringite formation (DEF) is a pathology that induces concrete swelling and cracking. Factors contributing to DEF have been identified experimentally, but on the modelling side the link between DEF-inducedexpansionandtheevolutionofconcreteandmortarphysicalproperties hasbeenlessstudied. Amulti-scaleporomechanicalmodelisintroducedwhichfeaturesadescription of DEF induced mortar damage by progression of microcracking. The model considers mortar as a three phases material that is constituted of cement paste, sand and micro-cracks. The Mori-Tanaka scheme is used to homogenise the poroelastic properties of the mortar. The loading parameters are a macroscopicstrainandanexpansivefreestraininducedbyDEFincementpaste. Damageprogression by micro cracking is accounted for by a Griffith-like energy criterion. The model allows to link the DEF-inducedexpansion at both the microscopic and macroscopic scales to the loss of stiffness of the mortar. A comparison of the model to experimental data on mortars formulated with CEM I cement and natural silica sand is carried out.