Two-phase damage modeling of concrete affected by alkali–silica reaction under variable temperature and humidity conditions

Multiscale hydro-thermo-chemo-mechanical coupling: Application to alkali–silica reaction

“…Moreover, the volumetric expansion of the gel was evaluated as a function of the reaction kinetics, which is influenced by the temperature. Comi et al [31] developed the model based on [3], where not only temperature but also relative humidity contribute to the extent of the reaction. In addition, the investigation on ASR at the macroscale of the concrete was developed by Bangert et al [30], where the concrete was treated as a mixture of three superimposed constituents through the theory of porous media: skeleton, pore liquid and pore gas.…”

“…The work [40] proposed that the dissolution stage can be described by a first-order kinetic law, which was widely adopted -see [3,29,31,41]. In addition, Larive [41] verified the dependence of the chemical reaction kinetics on the temperature and the relative humidity.…”

“…Macroscale Mechanical [19][20][21][22][23] Extensive work has been carried out to identify the expansion strain as a function of the stress tensor Macroscale Chemo-mechanical [24][25][26]15,27] A nonlinear relation between the expansion strain of concrete and the chemical extent was adopted to construct a model at the structural level Macroscale Hydro-thermochemo-mechanical [3,[28][29][30][31][32] Temperature and relative humidity contributed to the chemical extent of ASR and the expansion strain, leading to the failure of the concrete structure Mesoscale Chemo-mechanical [16,[33][34][35][36][37] Randomly distributed aggregates were embedded in the matrix to represent the mesoscale of the concrete. The formation and expansion of ASR gel are described at the level of each individual aggregate.…”

Lithuanian Quarry Aggregates Concrete Effects of Alkaline Corrosion Tests / Lietuvos Karjerų Užpildų Poveikio Betono Šarminei Korozijai Tyrimai

“…Alkali silica reaction ASR) yra viena iš cheminių reakcijų, kurios turi didelę įtaką betono ilgaamžiškumui. Vykstant šarmų ir silicio reakcijai tam tikros silicio formos, esančios betono užpilduose, reaguoja su dideliu šarmų kiekiu, taip betono mikroporose susidaro higroskopinis gelis, kuris, esant drėgnai aplinkai, plečiasi ir lėtai, bet stipriai ardo betonines konstrukcijas (Comi et al 2012;Martin et al 2012;Pacheco-Torgal et al 2011).…”

“…Bendruoju požiūriu vanduo atlieka iš esmės labai svarbų vaidmenį šarminėje korozijoje dėl šių priežasčių (Comi et al 2012): tai sudaro pernašos terpę hidroksilo ir šarminių jonų difuzijai per poras; vanduo sudaro palankias sąlygas nutraukti siloksano ryšiams, taigi kartu ir geliui formuotis; gelio plėtimosi procesas yra reglamentuojamas atsižvelgiant į vandens absorbciją ir vandens judėjimą porėta betono struktūra (makrodifuzija).…”