State of the Art for Fabricating and Emplacing Concrete Containers Into Large Horizontal Disposal Caverns in the French Geological Repository

2011 ◽  
Author(s):  
Jean-Michel Bosgiraud ◽  
Maurice Guariso ◽  
Franc¸ois Pineau
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
State Of The Art ◽  
Gantry Crane ◽  
Deep Geological Repository ◽  
Initial Development ◽  
The Public ◽  
Building Process ◽  
License Application ◽  
Geological Repository

The research and development work presented in this paper was initialized by Andra in 2007. The work necessary for manufacturing and testing a full scale demonstrator is presently implemented. The case story is twofold. The first part is related to the initial development of a high performance concrete formulation used for fabricating concrete storage containers (containing Intermediate Level and Long Lived Waste primary canisters) to be stacked and emplaced into 400-m long concrete lined horizontal disposal vaults (also called cavern), excavated in the Callovo-Oxfordian clay host formation at a 550 to 600-m depth, with an inside diameter of approximately 8-m. The fabrication of the concrete boxes is illustrated. The second part presents the outcome at the end of the detailed design phase, for a system which is now being manufactured (for further test and assembly), for the emplacement of the concrete containers inside the vault. The application was engineered for remote emplacing a pile of 2 concrete containers (the containers are preliminarily stacked in a pile of 2, inside a hot cell, thanks to a ground travelling gantry crane). The emplacement process is justified and the related emplacement synoptic is illustrated. The test campaign is scheduled in 2011–2012. The successful completion of the technical trials is mandatory to confirm the mechanical feasibility of remotely emplacing concrete containers into large horizontal disposal caverns over long distances. The later display of the machinery at work in Andra’s showroom will be instrumental for the confidence building process involving the various stakeholders concerned by the public enquiry period (mid-2013) preceding the deep geological repository license application (2014–2015).

Retrievability: A False Positive?!?

2001 ◽  
Author(s):  
Leif G. Eriksson
Keyword(s):  
False Positive ◽  
Future Generations ◽  
Public Acceptance ◽  
Public Confidence ◽  
Deep Geological Repository ◽  
Preliminary Conclusion ◽  
The Public ◽  
Geological Repository ◽  
Deep Geological Repositories

Abstract Retrieval (and various permutations of this term) of long-lived radioactive wastes/materials (LLRMs) from deep geological repositories is a “concept” currently believed to increase public confidence in, and acceptance of, national LLRM-repository programs. If the “retrievability concept” provides the missing link to increased public acceptance, which is imperative in a democratic society for the siting and development of a deep LLRM repository, then the understanding and expectations of the terms used must be clearly defined, and the associated benefits and shortcomings clearly explained, to the public. To quote the Danish mathematician and philosopher Piet Hein: Knowing what you knowest not is in a sense omniscience. Based on more than 20 years of involvement in the development of deep geological repositories for LLRMs in the United Sates of America and abroad, it is the preliminary conclusion of this author that retrievability conveys a false positive because it: 1. Does not add any appreciable post-closure physical safety to current and future generations and environments. 2. Could compromise (but does not necessarily have to) the long-term integrity of the disposal system. 3. Conveys the erroneous message that this generation does not have confidence in its ability to design, construct, decommission, and close a deep geological repository for LLRMs, in a manner that provides long-term containment and isolation of the emplaced LLRMs.

scholarly journals State of the Art: Mechanical Properties of Ultra-High Performance Concrete

2017 ◽  
Vol 3 (3) ◽  
pp. 190-198 ◽  
Author(s):  
Mohamadtaqi Baqersad ◽  
Ehsan Amir Sayyafi ◽  
Hamid Mortazavi Bak
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
High Performance Concrete ◽  
State Of The Art ◽  
High Strength ◽  
Structural Members ◽  
Ultra High Performance Concrete ◽  
Conventional Concrete ◽  
The Past ◽  
Very High

During the past decades, there has been an extensive attention in using Ultra-High Performance Concrete (UHPC) in the buildings and infrastructures construction. Due to that, defining comprehensive mechanical properties of UHPC required to design structural members is worthwhile. The main difference of UHPC with the conventional concrete is the very high strength of UHPC, resulting designing elements with less weight and smaller sizes.  However, there have been no globally accepted UHPC properties to be implemented in the designing process. Therefore, in the current study, the UHPC mechanical properties such as compressive and tensile strength, modulus of elasticity and development length for designing purposes are provided based on the reviewed literature. According to that, the best-recommended properties of UHPC that can be used in designing of UHPC members are summarized. Finally, different topics for future works and researches on UHPC’s mechanical properties are suggested.

Cable-Stayed Footbridge with UHPC Segmental Deck

2014 ◽  
Vol 629-630 ◽  
pp. 64-70 ◽  
Author(s):  
Milan Kalný ◽  
Vaclav Kvasnička ◽  
Jan Komanec ◽  
Jan L. Vítek ◽  
Robert Broz ◽  
...  
Keyword(s):  
Life Cycle Cost ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Light Weight ◽  
Ultra High Performance Concrete ◽  
Ongoing Research ◽  
The Czech Republic ◽  
The Public ◽  
Design And Implementation

Ongoing research and development of ultra-high performance concrete (UHPC) in the Czech Republic has been utilized in design and implementation of light-weight segmental deck of the cable-stayed footbridge over the Labe River in Celakovice with main span of 156 m. Detailing, design issues, construction method and efficiency of using UHPC on this large span lightweight bridge is described in the paper. The superstructure of the Celakovice footbridge was completed in the December 2013 and the bridge was opened for the public in April 2014. Main advantages of this project is not only low maintenance and reasonable life cycle cost but also favourable tender price which was achieved by the contractor Metrostav a.s. due to combination of high-strength modern materials steel and UHPC.

scholarly journals Review on the research progress of cement-based and geopolymer materials modified by graphene and graphene oxide

2020 ◽  
Vol 9 (1) ◽  
pp. 155-169 ◽  
Author(s):  
Changjiang Liu ◽  
Xiaochuan Huang ◽  
Yu-You Wu ◽  
Xiaowei Deng ◽  
Jian Liu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Environmental Protection ◽  
High Performance ◽  
High Performance Concrete ◽  
Research Progress ◽  
Large Specific Surface Area ◽  
New Materials ◽  
The Public ◽  
Cement Based Materials ◽  
Development Prospects

AbstractIn recent years, with the higher requirements for the performance of cement-based materials and the call for energy conservation and environmental protection, a wave of research on new materials has set off, and various high-performance concrete and more environmentally friendly geopolymers have appeared in the public. With a view to solving the defects of energy consumption, environmental protection and low toughness of traditional cement-based materials. At the same time, nanomaterials have become a focus of current research. Therefore, the research on the properties of cement-based materials and geopolymers modified by graphene and its derivatives has aroused extensive interest of researchers. Graphene-based nanomaterials are one of them. Because of their large specific surface area, excellent physical properties have been favored by many researchers. This paper reviews the research progress of graphene-based nanomaterials in improving the properties of cement-based materials and geopolymer materials, and points out the main challenges and development prospects of such materials in the construction field in the future.

scholarly journals Behaviour of high-performance concrete at high temperatures: some highlights

2017 ◽  
Vol 2 ◽  
pp. 45-52 ◽  
Author(s):  
Pierre Pimienta ◽  
Maria Cruz Alonso ◽  
Robert Jansson McNamee ◽  
Jean-Christophe Mindeguia
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
High Performance ◽  
High Performance Concrete ◽  
State Of The Art ◽  
Technical Committee ◽  
Rilem Technical Committee ◽  
Civil Structures ◽  
Physicochemical Changes ◽  
Materials Used

High-performance concrete (HPC) is one of the most recent types of concrete among the materials used routinely in building and civil structures. Their development in structures applications and the growing need for the justification of their fire resistance has led several laboratories to carry out research on their properties at high temperature. This letter presents some main aspects related to their physicochemical changes, thermal properties and mechanical properties at high temperature. It introduces a State of The Art prepared by the RILEM Technical Committee 227-HPB (Physical properties and behaviour of High-Performance Concrete at high temperature) and untitled “Behaviour of High-Performance Concrete at high temperatures”. This State of the Art will be publish in a next future.

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