Methodology for numerical analysis of structures affected by delayed ettringite formation Available to Purchase

Delayed ettringite formation (DEF) is an origin of concrete degradation and can cause serious damage to major engineering structures. A methodology for carrying out a numerical analysis of DEF-affected structures is proposed in order to offer diagnosis and prognosis and thus optimise their maintenance. A methodology in two phases, calibration and validation, was developed and applied to laboratory beams presented in the literature, with different reinforcement ratios, uniformly heated at young age and subjected to water gradients. At present, few numerical models are capable of faithfully reproducing the behaviour of structures damaged by DEF at this scale because of the diversity of phenomena to be considered (shrinkage, creep, temperature, alkali leaching, pressure generated by the DEF, anisotropic cracking). A thermo-hydro-chemo-mechanical model was applied. The modelling results showed good accordance with observations. However, multiphysics parametric analyses are necessary to obtain relevant calibration owing to the high non-linearity of the phenomena. A methodology applicable to field work was also developed, taking into account the heterogeneity in the temperature reached at young age and the probable lack of calibration data.