Reference number : GC-2017-Q1-03377, amendment number : , agreement type : G, recipient legal name : COLLINS, MICHAEL (University of Toronto), recipient country : CA, recipient province : nan, recipient city : Ontario, recipient postal code : nan, program name english : Discovery Grants Program - Individual, program name french : Programme de subventions à la découverte - individuelles, program purpose english : The objectives of this long-term research program are to improve understanding of the mechanisms by which cracked reinforced concrete transmits shear stresses and use this understanding to develop analytical tools which structural engineers can use to design new structures and evaluate the safety of existing concrete structures. Shear failures can cause concrete structures to collapse without warning and, hence, are of critical concern for public safety. It is now known that older North American shear and torsion design procedures used for a significant portion of existing concrete infrastructure can result in buildings, bridges, silos and nuclear power plants which may have inadequate margins of safety against such failures. Such structures are particularly prone to collapse during earthquakes. 
One of the major objectives of the next five years is to improve the understanding of combined torsion and shear and develop the tools to decide which structures must be repaired. This will be done by conducting experiments on intensely instrumented elements of reinforced concrete subjected to loading that simulate the actual conditions encountered in practice. Recently developed techniques will be improved to enable the formation, propagation and sliding of critical cracks to be recorded so that the characteristics of crack patterns of impending shear collapse can be accurately defined. The influence of reversed cyclic loading on crack propagation and bond deterioration for members containing reinforcement details representative of those in older existing structures will be studied and the effects of restraint of shrinkage and thermal movement will be simulated. The experimental studies will be supplemented with extensive nonlinear 2D and 3D finite element analysis. Finally, simple analytical models suitable for use by practicing engineers to evaluate existing structures for shear safety will be developed. The research will be conducted by graduate students who will develop a deep understanding of the shear behaviour of reinforced concrete structures under extreme loads. After such research they will be equipped to contribute to the safety assessment of Canada&rsquo;s critical concrete infrastructure., program purpose french : The objectives of this long-term research program are to improve understanding of the mechanisms by which cracked reinforced concrete transmits shear stresses and use this understanding to develop analytical tools which structural engineers can use to design new structures and evaluate the safety of existing concrete structures. Shear failures can cause concrete structures to collapse without warning and, hence, are of critical concern for public safety. It is now known that older North American shear and torsion design procedures used for a significant portion of existing concrete infrastructure can result in buildings, bridges, silos and nuclear power plants which may have inadequate margins of safety against such failures. Such structures are particularly prone to collapse during earthquakes. 
One of the major objectives of the next five years is to improve the understanding of combined torsion and shear and develop the tools to decide which structures must be repaired. This will be done by conducting experiments on intensely instrumented elements of reinforced concrete subjected to loading that simulate the actual conditions encountered in practice. Recently developed techniques will be improved to enable the formation, propagation and sliding of critical cracks to be recorded so that the characteristics of crack patterns of impending shear collapse can be accurately defined. The influence of reversed cyclic loading on crack propagation and bond deterioration for members containing reinforcement details representative of those in older existing structures will be studied and the effects of restraint of shrinkage and thermal movement will be simulated. The experimental studies will be supplemented with extensive nonlinear 2D and 3D finite element analysis. Finally, simple analytical models suitable for use by practicing engineers to evaluate existing structures for shear safety will be developed. The research will be conducted by graduate students who will develop a deep understanding of the shear behaviour of reinforced concrete structures under extreme loads. After such research they will be equipped to contribute to the safety assessment of Canada&rsquo;s critical concrete infrastructure., agreement title english : Shear and Torsion Response of Reinforced Concrete Structures, agreement title french : Shear and Torsion Response of Reinforced Concrete Structures, agreement number : RGPIN, agreement value : 255000.0, agreement start date : 2017-05-10, agreement end date : nan, description english : nan, description french : nan, expected results english : nan, expected results french : nan, additional information english : Grant or Award spanning more than one fiscal year. (2017-2018 to 2022-2023), additional information french : Subvention ou bourse octroyée s'appliquant à plus d'un exercice financier. (2017-2018 à 2022-2023), owner organization : nserc-crsng, owner organization title : Natural Sciences and Engineering Research Council of Canada | Conseil de recherches en sciences naturelles et en génie du Canada