Virtual MEchanics GAthering -MEGA- Seminar: What makes dams move: mechanics of alkali-silica reaction through modelling

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Event details

Date and time 04.03.2021 16:1517:30  
Place and room
https://epfl.zoom.us/s/84678428267 Passcode: 174387
Online https://epfl.zoom.us/s/84678428267
Speaker Emil Gallyamov (LSMS, EPFL)
Category Conferences - Seminars
Abstract Alkali-silica reaction (ASR) in concrete occurs between alkalis of mortar and silica contained in aggregates. It results in growth of either amorphous or crystalline product that imposes internal pressure upon concrete. This leads to expansion and cracks development. High water saturation and elevated temperatures trigger ASR and accelerate material deterioration.

ASR activated massive concrete structures, such as hydraulic dams, bridge piers and sea walls, deserve special attention due to their elevated safety requirements. To predict their behaviour, numerical modelling is widely used. However, the scale of the driving process (ASR) is separated from the scale of interest (macroscopic displacements and stresses) by few orders of magnitude.

We have proposed a multi-scale approach that models ASR evolution at the concrete meso-scale and updates deformations and expansion at the macro-scale. A distinguishing feature of this multi-scale model is the combination of macro-scale loads (water pressure, self-weight, etc.) and the internal meso-scale loading (ASR product pressure). In response to both types of load, meso-scopic representative volume element (RVE) can develop cracks that are modelled by orthotropic continuum damage with stiffness recovery upon closure.

The proposed model is applied to a cross-section of a middle-sized ASR-affected concrete gravity dam in Alps region of Switzerland. Simulation results are compared with the field measurements and observations.

Bio Emil Gallyamov is a PhD student in the Computational Solid Mechanics Laboratory, under the scientific supervision of Prof. J.-F. Molinari. He first graduated as a civil engineer in the Ufa State Petroleum Technological University (Russia) in 2010. Five following years he had spent working in the upstream oil & gas industry around the globe. Before coming to Lausanne, he obtained his M.Sc. in Geotechnics in the Technical University of Delft (Netherlands) in 2017. During his studies, he got interested in numerical methods in mechanics, which brought him to his PhD devoted to numerical modelling of concrete.
 

Practical information

  • General public
  • Free

Organizer

  • MEGA.Seminar Organizing Committee

Tags

Solids Structures Fluids

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