9. September 2021, 13:00 15:00
Webinar via Zoom
Alkali-silica reaction (ASR) causes cracking and with it substantial damages in concrete structures worldwide causing substantial costs due to repair or replacement. Although ASR is one of the major focal points of concrete research since the first cases were reported in the 1940's, our knowledge is still not sufficient to understand various aspects of the reaction. This includes the understanding about various steps in the mechanisms of the reaction, the products formed and damage development. In an ASR-project funded by the Swiss National Science Foundation (SNF CRSII5_171018) multidisciplinary approach was used to study ASR from the nano to the metre scale using dissolution experiments, thermodynamic modelling, structural analysis, 2-D characterization, 3D imaging and computational modelling. Six subprojects were conducted at four different institutes benefiting from the synergistic effects provided by a close collaboration.
In the webinar we will present selected highlights of the project:
Aggregate dissolution, Mahsa Bagheri
Dissolution experiments and pore solution analysis provide insight on ions affecting SiO2 dissolution.
Initially formed products, Solène Barbotin
Using a combination of focus ion beam and transmission electron microscopy the composition and structure of the initially formed ASR products are analyzed with a resolution down to the sub-micrometer range.
Atomic structure of ASR products, Guoqing Geng and Francesco Marafatto
The atomic structure of naturally formed and synthesized ASR products are identified by using spectroscopic techniques at synchrotrons.
Synthetic ASR products, Zhenguo Shi
The synthesis of amorphous and crystalline ASR products shows the effect of temperature on their structure and provides the base for a comparison with naturally formed products.
ASR products and cracking: a 4D view, Mahdieh Shakoorioskooie
The formation of ASR products and crack propagation are followed by high-resolution X-ray micro-tomography providing a 4D-view of the reaction.
Numerical modelling of mechanics, Emil Gallyamov
The numerical modelling of mechanics is based on realistic microstructure provided by 3D-analysis of crack formation.