High Performance Concrete Recommended Extensions To The Model Code 90 Research Needs

"In 1993, the CEB Commission 2 Material and Behavior Modelling established the Task Group 2.5 Bond Models. It's terms of reference were ... to write a state-of-art report concerning bond of reinforcement in concrete and later recommend how the knowledge could be applied in practice (Model Code like text proposal)... {This work} covers the first part ... the state-of-art report."--Pref.

fib Model Code 2010 represents the state-of-the-art of code-type models for structural behaviour of concrete. It comprises constitutive relations and material models together with the most important explanatory notes. However the underlying normative work, i.e. the fundamental data as well as the considerations and discussions behind the formulas could not be given within the Model Code text. Based on various experiences gained after the publication of Model Code 1990 this lacking background information will lead in the following to numerous questions arising from Model Code users. Consequently the present bulletin claims to conquer this general weakness of codes in a way to guard against any future misunderstandings of the Model Code 2010 related to its chapter 5.1 (Concrete). It discusses the given formulas in connection with experimental data and the most important international literature. The constitutive relations or material models, being included in MC1990 and forming the basis and point of origin of the Task Group’s work, were critically evaluated, if necessary and possible adjusted, or replaced by completely new approaches. Major criteria have been the physical and thermodynamical soundness as well as practical considerations like simplicity and operationality. This state-of-the-art report is intended for practicizing engineers as well as for researchers and represents a comprehensible summary of the relevant knowledge available to the members of the fib Task Group 8.7 at the time of its drafting. Besides the fact that the bulletin is a background document for Chapter 5.1 of MC2010, it will provide an important foundation for the development of future generations of code-type models related to the characteristics and the behaviour of structural concrete. Further it will offer insights into the complexity of the normative work related to concrete modelling, leading to a better understanding and adequate appreciation of MC2010.

High Strength/High Performance Concrete (HSC/HPC) continues to be the object of particular interest and extensive research, and its use in construction is increasing continuously. fib Bulletin 42 summarises the available information on the material behaviour of HSC/HPC, and develops a set of code-type constitutive relations as an extension of CEB-FIP Model Code 1990. Literature on experimental data and international guidelines, standards and recommendations were reviewed, and already-existing constitutive relations and models were evaluated. In addition to a number of material laws chosen and adjusted for this report, some new constitutive relations were developed based on the collected data. The criteria for the choice of the existing relations as well as the development of the new constitutive relations involved their simplicity and operationality (code-type mathematical formulations). Furthermore, they had to be physically sound and if possible describe the behaviour of both high-performance and normal strength concretes by a unique relation. Finally, compliance with the specifications given in the CEB-FIP Model Code 1990 was examined. This State-of-art report is intended for engineers and represents a summary of the relevant knowledge available to and possessed by the members of the Task Group at the time of its drafting.

Developments in the Formulation and Reinforcement of Concrete, Second Edition, presents the latest developments on topics covered in the first edition. In addition, it includes new chapters on supplementary cementitious materials, mass concrete, the sustainably of concrete, service life prediction, limestone cements, the corrosion of steel in concrete, alkali-aggregate reactions, and concrete as a multiscale material. The book's chapters introduce the reader to some of the most important issues facing today's concrete industry. With its distinguished editor and international team of contributors, users will find this to be a must-have reference for civil and structural engineers. Summarizes a wealth of recent research on structural concrete, including material microstructure, concrete types, and variation and construction techniques Emphasizes concrete mixture design and applications in civil and structural engineering Reviews modern concrete materials and novel construction systems, such as the precast industry and structures requiring high-performance concrete

Part 1 – Recommended extensions to Model Code 90 Starting in 1995 as a Joint CEB/FIP Working Group on Lightweight Aggregate Concrete (LWAC), the group was after the merger of CEB and FIP attached to the new fib Commission 8 Concrete. As a background for an extension of the CEB/FIP Model Code 1990 (MC 90) it delivered firstly Bulletin 4. Similarly to what has been done before in the field of High Strength / High Performance Concrete the present guide identifies the lacunae in the existing MC90 and proposes supplementary or alternative solutions to be applied for lightweight aggregate concretes. In order to facilitate its use the report is edited in two columns following the numbering of the CEB-FIP Model Code 1990. The group has given preference to topics of practical importance for LWAC structures, and for which reliable information is available. Justifications of the proposed extensions are to be found in the references to each section. Part 2 – Identification of research needs The technical report identifies the research needs resulting from those clauses of MC 90 which need amendment, and for which more basic research should provide a better understanding of mechanical, physical and chemical processes. Part 3 – Application of lightweight aggregate concrete The state-of-art report documents 33 application examples of projects world-wide. Twenty-eight two-page and five one-page presentations aim to explain the motivation for adopting this technology and report on the design considerations and codes applied, the practical experience during design and construction, the results obtained and the infield performance; for each example references list the literature where more detailed information can be found.

Over 150 papers representing the most recent international research findings on steel and composite structures. Including steel constructions; buckling and stability; codes; composite; control; fatigue and fracture; fire; impact; joints; maintenance; plates and shells; retrofitting; seismic; space structures; steel; structural analysis; structural components and assemblies; thin-walled structures; vibrations, and wind. A special session is dedicated on codification. A valuable source of information to researchers and practitioners in the field of steel and composite structures.