Numerical Modeling of AAR


Book Description

This reference book presents the theory and methodology to conduct a finite element assessment of concrete structures subjected to chemically induced volumetric expansion in general and alkali aggregate reaction in particular. It is limited to models developed by the author, and focuses on how to best address a simple question: if a structure suffers from AAR, how is its structural integrity jeopardized, and when would the reaction end. Subjects treated are: • Brief overview of AAR: nature of the chemical reactions, AAR in both dams and nuclear power plants, and how does it impact the mechanical properties of concrete. • Constitutive model for both the AAR expansion, and concrete nonlinearities (both smeared and discrete crack models). • Validation of the model along with a parametric study to assess what are the critical parameters in a study. • Selection of material properties for an AAR finite element simulation, followed by applications in dams and massive reinforced concrete structures. • Micro Model for improved understanding of the essence of the reaction, along with a newly proposed mathematical model for the kinetics of the reaction. • Review of relevant procedures to estimate the residual expansion of a structure suffering from AAR, along with a proposed approach to determine when the reaction will end. The book is extensively illustrated with numerous figures and provides guidance to engineers confronted with swelling in concrete infrastructures.




Numerical Modeling Strategies for Sustainable Concrete Structures


Book Description

This volume highlights the latest advances, innovations, and applications in the field of sustainable concrete structures, as presented by scientists and engineers at the RILEM International Conference on Numerical Modeling Strategies for Sustainable Concrete Structures (SSCS), held in Marseille, France, on July 4-6, 2022. It demonstrates that numerical methods (finite elements, finite volumes, finite differences) are a relevant response to the challenge to optimize the utilization of cement in concrete constructions while checking that these constructions have a lifespan compatible with the stakes of sustainable development. They are indeed accurate tools for an optimized design of concrete constructions, and allow us to consider all types of complexities: for example, those linked to rheological, physicochemical and mechanical properties of concrete, those linked to the geometry of the structures or even to the environmental boundary conditions. This optimization must also respect constraints of time, money, security, energy, CO2 emissions, and, more generally, life cycle more reliably than the codes and analytical approaches currently used. Numerical methods are, undoubtedly, the best calculation tools at the service of concrete eco-construction. The contributions present traditional and new ideas that will open novel research directions and foster multidisciplinary collaboration between different specialists.







Alkali-Aggregate Reaction in Concrete


Book Description

Alkali-Aggregate Reaction in Concrete: A World Review is unique in providing authoritative and up to date expert information on the causes and effects of Alkali-Aggregate Reaction (AAR) in concrete structures worldwide. In 1992 a first edition entitled The Alkali-Silica Reaction in Concrete, edited by Professor Narayan Swamy, was published in a first attempt to cover this concrete problem from a global perspective, but the coverage was incomplete. This completely new edition offers a fully updated and more universal coverage of the world situation concerning AAR and includes a wealth of new evidence and research information that has accumulated in the intervening years. Although there are various textbooks offering readers sections that deal with AAR deterioration and damage to concrete, no other single book brings together the views of recognised international experts in the field, and the wealth of scattered research information that is available. It provides a ‘state of the art’ review and deals authoritatively with the mechanisms of AAR, its diagnosis and how to treat concrete affected by AAR. It is illustrated by numerous actual examples from around the world, and comprises specialist contributions provided by senior engineers and scientists from many parts of the world. The book is divided into two distinct but complementary parts. The first five chapters deal with the most recent findings concerning the mechanisms involved in the reaction, methods concerning its diagnosis, testing and evaluation, together with an appraisal of current methods used in its avoidance and in the remediation of affected concrete structures. The second part is divided into eleven chapters covering each region of the world in turn. These chapters have been written by experts with specialist knowledge of AAR in the countries involved and include an authoritative appraisal of the problem and its solution as it affects concrete structures in the region. Such an authoritative compilation of information on AAR has not been attempted previously on this scale and this work is therefore an essential source for practising and research civil engineers, consultant engineers and materials scientists, as well as aggregate and cement producers, designers and concrete suppliers, especially regarding projects outside their own region.




Numerical Models in Geomechanics


Book Description

In this volume a number of developments on a variety of topics have been reported. These topics include: partially saturated soil; instabilities in soil behaviour; environmental geomechanics; parallel computing; and applications to tunnels, embankments, slopes, foundations and anchors.




Dam Maintenance and Rehabilitation


Book Description

During the life of a dam, changes in safety standards, legislation and land use will inevitably occur, and functional deterioration may also appear. To meet these challenges, these Proceedings from a panel of international experts assess, define and re-evaluate the design criteria for the construction of dams and the many attendant issues in on-going maintenance and management. Authors include international specialists: academics, professionals and those in local government, utilities and suppliers. Practitioners from these same fields will find the book a useful tool in acquiring a comprehensive knowledge of managing and retrofitting dams, so that they can continue to meet society's needs.




Exhumation Processes


Book Description




Swelling Concrete in Dams and Hydraulic Structures


Book Description

The swelling of concrete is a major concern for the owners and operators of dams and hydraulic structures. Faced with irreversible movement of their dams or with observations of cracking processes, operators need to explain the phenomena observed in order to justify safety conditions and in some cases to plan remedial works. Over the last 20 years, active research has been carried out in the field, resulting in practical results in phenomena interpretation and dam modeling. At the same time, an increasing number of affected dams have undergone safety re-evaluations and in some cases remedial work. Several of them have been removed altogether. Although it remains difficult to establish a “state of the art” in this domain due to the rapidly changing context, regular international exchanges in the field appear fruitful and necessary. Following on from previous conferences in the field organized by Robin Charlwood, former President of the ICOLD Concrete Committee, the initiative was taken by EDF and Toulouse University-LMDC to organize a workshop to provide a new opportunity for sharing experience. The aim of this workshop is to assemble active researchers, leading engineers, and experts from the practicing community and administration interested directly or indirectly in concrete swelling effects in dams and hydraulic structures. All types of chemical expansion phenomena, including those due to alkali aggregate reactions and those due to ettringite formation, are addressed. These proceedings include 24 papers written by experts renowned in their field, illustrating the need to progress with interdisciplinary approaches.




Dam-break Problems, Solutions and Case Studies


Book Description

The aim of the book is to give an up-to-date review on dam-break problems, along with the main theoretical background and the practical aspects involved in dam failures, design of flood defense structures, prevention measures and the environmental social, economic and forensic aspects related to the topic. Moreover, an exhaustive range of laboratory tests and modeling techniques is explored to deal effectively with shock waves and other disasters caused by dam failures. Disaster management refers to programs and strategies designed to prevent, mitigate, prepare for, respond to and recover from the effects of these phenomena.To manage and minimize these risks, it is necessary to identify hazards and vulnerability by means of a deep knowledge of the causes which drive to dam failures, and to understand the flow propagation process.Knowledge and advanced scientific tools play a role of paramount importance of coping with flooding and other dam-break problems along with capacity building in the context of political and administrative frameworks. All these aspects are featured in the book, which is a comprehensive treaty that covers the most theoretical and advanced aspects of structural and hydraulic engineering, together with the hazard assessment and mitigation measures and the social economic and forensic aspects related to subject.




Dam Maintenance and Rehabilitation


Book Description

During the life of a dam, changes in safety standards, legislation and land use will inevitably occur, and functional deterioration may also appear. To meet these challenges, these Proceedings from a panel of international experts assess, define and re-evaluate the design criteria for the construction of dams and the many attendant issues in on-going maintenance and management. Authors include international specialists: academics, professionals and those in local government, utilities and suppliers. Practitioners from these same fields will find the book a useful tool in acquiring a comprehensive knowledge of managing and retrofitting dams, so that they can continue to meet society's needs.