Update on the journey to fib MC2020
Find out about fib MC2020's progress in this update!
Discussions during 2014 and 2015 on potential ways of advancing the fib Model Code for Concrete Structures resulted in a workshop being held in The Hague (the Netherlands) in June 2015 and the formation of the MC2020 Core Group in December 2015. These activities established that there was a need for a single structural code dealing with both new and existing concrete structures; that is concerned with both the design of new structures and all the activities associated with the assessment, interventions and the through-life management of existing concrete structures.
In February 2016 the MC2020 Core Group presented a roadmap for advancing the fib Model Code for Concrete Structures which included a recommendation that fib Commission 10 should be established, with its main purpose being to have a permanent focus on steering development of the fib Model Code (and that of any other supporting Codes or Specifications which might be found to be required). This recommendation was endorsed by the following fib Technical Council (TC) meeting in Madrid in June 2016. Task Group 10.1 – Model Code 2020 was created at the first meeting of Commission 10 held in Lausanne in October 2016.
Since its inauguration TG10.1 has held six MC2020 project meetings in Lausanne, Switzerland (October 2016, 2 days); Delft, the Netherlands (March 2017, 2 days); Barcelona, Spain (December 2017, 2 days); Lausanne, Switzerland (April 2018, 2 days); Melbourne, Australia (October 2018, 1 day) and Karlsruhe, Germany (December 2018, 2 days).
Scope of the technical work
The vision for the fib MC2020 goes beyond the point reached by fib MC2010, recent ISO codes (such as ISO 16311) and the current activities to extend the application of Eurocodes and other national/international standards dealing with existing concrete structures. It is clear from discussions at the fib Technical Council that both Commission 10 and TG10.1 should seek wide international involvement.
The fib MC2020 is taking sustainability as a fundamental requirement, based upon a holistic treatment of societal needs and impacts, life-cycle cost and environmental impacts, with these being aligned with the United Nations Sustainable Development Goals defined in 2015.
MC2020 provides an important opportunity to further advance current approaches to the sustainable design, construction and through-life management of concrete structures. Central to this will be how we formulate and verify performance requirements for concrete structures within a holistic sustainability framework utilising the widely-accepted ‘three pillars of sustainability’ of social, environmental and economic performance. Such an approach provides a way to recognise the great benefits concrete structures provide to humankind’s global society, along with their impacts on that society and the wider environment, as well as their economic cost and return.
Adopting this integrated life-cycle approach, the requirements for social performance will have defining implications for subsidiary performance requirements critical to structural design and assessment procedures. These are matters such as human and environmental safety, structural reliability, design service life, durability, serviceability and other social aspects, such as aesthetics, adaptability, maintenance, etc.
Based upon the wider social context, there may be requirements for specific performances such as the robustness of the structure, the resilience of its functionality, etc.
The MC2020 discussions have highlighted the rapid pace of technical development in many areas, including those relating to materials, design, numerical analysis, structural assessment, monitoring, construction, and interventions, to mention just a few. It is anticipated that the pace at which such technical developments occur will continue to increase. MC2020 needs to be future looking so that it can accommodate and not hinder future technological progress, thereby facilitating the ongoing evolution of concrete and reinforcing materials, associated technologies, and the structural forms which could potentially be created using them.
New concrete materials and technologies will be critical components for reducing the environmental impacts of concrete construction. The simple substitution of additions, such as fly ash and blast-furnace slag powders for cement, will not be enough. New binders, together with new admixtures and processing technologies, will be needed. With their different chemistry, these pose new challenges but also offer new opportunities. Important considerations include their long-term performance and durability of concretes made with them in demanding service environments.
Also, we cannot forget the implications of potential developments in intervention materials and associated technologies for protection, repair, rehabilitation and enhancement of the current condition/performance of existing structures. These are fertile areas of technological advance.
Of course, the inclusion in MC2020 of activities associated with the through-life management and care of existing concrete structures also poses substantial challenges, especially when the potential ramifications of damage and material deterioration are considered. The inclusion of these aspects has necessitated some restructuring of the code document and will involve the introduction of significantly more information about the processes and procedures involved. In order to keep MC2020 to a manageable size, it is proposed that valuable background material be contained in supporting fib Bulletins. This principle will also apply to other topics addressed in MC2020.
In terms of specific points to be addressed in MC2020, many of these relate to the following:
- Revision and/or extension of basic principles and concepts
- Revision and/or development of principles of structural design and assessment
- Extension of the provisions on materials and their modelling
- Extension of the provisions on interface characteristics between different materials
- Revision of the provisions for the design and the development of provisions for assessment
- Extension of the provisions relating to construction and interventions
- Updating the provisions relating to conservation and through-life management & care, and
- Updating / extending the provisions on recycling, dismantlement and end of life aspects
Model Code 2020 has adopted a through-life management approach, for both new and existing structures, which involves addressing:
- Sustainability objectives that balance environment, social and cost perspectives,
- Promotion of structural safety, serviceability and durability,
- Use of advanced life-cycle cost methods,
- Reliability concepts that take account of uncertainties and risk,
- Use of performance-based concepts to remove inappropriate constraints on the use of novel types materials and approaches,
- Use of improved models for assessment of initiation and propagation phases that consider the structural, risk and reliability implications,
- Provision of generalised models allowing for implementation of the level of approximation approach,
- Attention to new types of concrete and new techniques for construction and interventions,
- Definition of test methods, and performance evaluation of concrete,
- Worldwide knowledge of materials and structural behaviour, and recognises the differing needs of engineering communities around the world,
- Recognition of the importance of robustness and redundancy in the behaviour of structures,
- Paying particular attention to the effect of material degradation,
- Guidance on dealing with structural arrangements which are not recognised in contemporary codes,
- Treatment of the end-of-service-life issues such as demolition and disposal including safety and structural aspects, and
- Guidelines to practitioners when provisions in other standards are deficient or lacking.
All commissions within the fib are contributing to the development, drafting and promotion of MC2020. Cooperation with international organisations is being sought via various mechanisms including the holding of joint events, such as the joint fib, JCSS and RILEM Durability Workshop held in November 2017 in Delft, the Netherlands. Such events provide an important focus and stimulus for participation in the work on technical topics and give a basis for the exploration of the range of technical practice employed in various regions of the world and by different professional groups. Another component of the activities to take the Model Code work forward are the MC2020 Action Groups which have been established to focus on specific technical topics. Currently, there are the following twelve Action Groups:
AG1 Action Group: Databases
AG2 Action Group: Shear and punching
AG3 Action Group: Bond
AG4 Action Group: Durability & service life design
AG5 Action Group: Detailing
AG6 Action Group: Fire
AG7 Action Group: Seismic design & assessment
AG8 Action Group: Non-linear finite element modelling (AG: NLFEM)
AG9 Action Group: Structural health monitoring and testing (AG: SHM and testing)
AG10 Action Group: Robustness
AG11 Action Group: Fatigue
AG12 Action Group: Impact and explosion
The vision for the MC2020 Action Groups is that they will draw together knowledge and expertise in their respective technical topic areas, both within and outside fib, as is appropriate in order to bring forward relevant contributions to MC2020.
Finally, consideration will need to be given to new ways of delivering MC2020, with digital delivery being foreseen alongside the traditional hardbound book format. A digital delivery format will facilitate the periodic maintenance of MC2020 by a standing committee, as well as its subsequent evolution.
Progress with the technical work and related activities
Good progress was made since TG10.1 was inaugurated over two years ago. Importantly we now have a well-defined Table of Contents (TOC) for MC2020, which is a critical item in facilitating and coordinating the preparation of draft text for MC2020. In this period the MC2020 TOC has evolved from a slightly enhanced version of the existing MC2010 TOC, to become the skeleton for the significantly extended and more complex MC2020 document which has a greatly extended technical scope and coverage. This progression reflects the process whereby TG10.1 has gradually come to terms with the many implications of the aspirations for MC2020 and the associated changes and developments. This evolution is illustrated by the following headline details:
- MC2010: 5Nr Parts and 10Nr Chapters
- MC2020: 9Nr Parts and 34Nr Chapters
Details of the 9Nr Parts and 34Nr Chapters forming the current MC2020 TOC proposal are presented below. Draft text for MC2020 is currently being prepared by fib Commission Task Groups, MC2020 Action Groups and individual authors based upon this version of the MC2020 TOC.
An important consideration is to make all this material as accessible and easy to use as possible for the target audience of practitioners and researchers involved in the design of new concrete structures and the though-life management and care of existing concrete structures, as well as those involved in national and international code committee activities.
Over the last two years a series of international MC2020 workshops and events, generally lasting one day, has been held as follows:
- September 2016: MC2020 regional workshop in Tokyo, Japan (in association with the fib PhD Symposium)
- November 2016: MC2020 regional workshop in Cape Town, South Africa (in association with the fib Symposium)
- June 2017: Special session on MC2020 in the fib Symposium in Maastricht, the Netherlands
- October 2017: MC2020 regional workshop in Sao Paulo, Brazil
- October 2017: MC2020 regional workshop in Adelaide, Australia (in association with the 3rd International Congress on Durability of Concrete (ICDC 2017))
- October 2017: The Gvozdev's Readings, Moscow
- November 2017: MC2020 workshop in association with JCSS and RILEM to discuss durability design and assessment issues, modelling and matters relating to the service life design of concrete structures (2 days).
- February 2018: MC2020 regional workshop in Denver, Colorado, USA (in association with the PCI convention in Denver)
- October 2018: MC2020 regional workshop in Shanghai, China
These produced wide-ranging discussions which touched upon many topics including the following.
- General concepts for sustainability and future model code advancement
- Fundamental principles and reliability concepts for new and existing structures
- Models and material characterisation for existing structures
- Inspection, maintenance and retrofitting of existing structures, and
- Evaluation of, decision-making about and management and care of existing structures.
General information on the vision for MC2020 and news updates have been published in Structural Concrete and the fib website or via other fib communications routes. These include:
- fib Model Code 2020—A new development in structural codes, Editorial in the fib journal Structural Concrete, Oct 2017.
In 2018 a number of supporting technical papers have been published in the fib journal Structural Concrete and in the proceedings of various international conferences. These publications and the associated presentations, which have helped inform a wider audience about various aspect of the vision for MC2020, include:
- fib MC2020 – Durability design and through life management of new and existing structures, paper given at ICDCS2018, Leeds, UK, July 2018.
- fib Model Code 2020: Towards a general code for both new and existing concrete structures, Overview paper in Structural Concrete, Aug 2018.
- fib MC2020 & structural models for existing concrete structures, paper given at the fib Congress in Melbourne, Oct 2018.
- fib MC2020 & existing concrete structures - Assessment, through-life management & interventions, paper given at BE2018 Conference, Lisbon, Nov 2018.
- fib MC2020: Forensic engineering and existing structures, paper given at ICCRRR 2018 Conference, Cape Town, Nov 2018.
As the MC2020 project moves into a period intensive working in 2019 and 2020, a number of future two-day TG10.1 meetings have been scheduled. The outline details are as follows:
April 2019: Lausanne, Switzerland;
May 2019: Krakow, Poland, in association with the fib Symposium;
October 2019: Lausanne, Switzerland;
December 2019: Tokyo, Japan; and
April 2020: Shanghai, China, in association with the fib Symposium.
It is recognised that the scale of the ambition of the MC2020 project, building on the achievements of fib MC2010, poses very significant challenges for those involved in this endeavour.
Further progress reports will appear from time to time in media such as fib-news, the Structural Concrete journal and the fib-website.
Stuart Matthews (Convener of TG10.1), Agnieszka Bigaj-van Vliet (Deputy-Convener of TG10.1), and Gerrie Dieteren (Technical Secretary of TG10.1)
MC2020 TOC Proposal - Version 12 November 2018
PART I SCOPE AND TERMINOLOGY
PART II BASIC PRINCIPLES
3. Sustainability perspective
4. Through-life management and care
5. Performance-based approach
6. Principles of structural design and assessment
7. Principles of execution
8. Principles of conservation
9. Principles of dismantlement and reuse
10. Principles of quality and information management
PART III ACTIONS ON STRUCTURES
11. Actions on structures
PART IV INPUT DATA FOR MATERIALS
13. Reinforcing steel
14. Prestressing steel & prestressing systems
15. Non-metallic reinforcement
16. Fibre reinforced concrete & UHPC
17. Protective materials & systems
PART V INPUT DATA FOR INTERFACES
18. Bond of embedded steel reinforcement
19. Bond of embedded non-metallic reinforcement
20. Bond of externally applied reinforcement
21. Concrete to concrete
22. Concrete to steel by mechanical interlock
23. Anchorages in concrete
PART VI DESIGN AND ASSESSMENT
24. Conceptual design
25. Approach to assessment
26. Structural analysis
27. Evaluation of structural performance
28. Evaluation of environmental performance
29. Evaluation of economic performance
30. Sustainability evaluation
PART VII EXECUTION
31. Execution management
32. Construction works
33. Execution of interventions
PART VIII CONSERVATION
PART IX DISMANTLEMENT AND REUSE
35. Dismantlement and reuse