fib Model Code 2020: Towards a general code for both new and existing concrete structures

Abstract

Discussions have been underway in fib (Fédération Internationale du Béton) about advancing the fib Model Code for concrete structures. These include the fib international workshop in The Hague (June 2015), the fib MC2020 Core Group meeting in Madrid (December 2015), and a series of follow‐up worldwide consultations on the fib ambition regarding the new developments in structural codes, including the special session on Model Code in the fib Symposium in Maastricht (June 2017). This paper discusses the main aspects of the development of fib MC2020, which is envisaged as a single‐merged general code fully integrating the provisions for the design of new concrete structures with matters relating to existing concrete structure. It needs to deal effectively with both the design of structures and all the activities associated with the through‐life management of existing concrete structures, including matters such as their in‐service assessment and interventions upon them. To that end, MC2020 will take sustainability as a fundamental requirement, based upon a holistic treatment of societal needs and impacts, life‐cycle cost and environmental impacts. This paper discusses the main aspects of the development of fib MC2020. As part of this, the envisaged contribution of fib T10.1: Model Code 2020 is reviewed. However, recognizing the overall ambition of the fib MC2020 project, it is clear that all fib commissions, along with other bodies able to make contributions on relevant topics, will need to work together to assemble the breadth of knowledge and expertise which will be required for the fib MC2020 project.

Reliability Approaches Affecting the Sustainability of Concrete Structures

“…In comparison to structural design, the basis of the assessment of existing structures assumes lower target reliabilities and reduced uncertainties when tests and measurements are taken on the existing structure. For further information on MC 2020, see ref [17].…”

“…It is broadly recognised that concrete has a leading role in construction; for instance, the calibrations of partial factors in Eurocodes [18] assumed a weight of concrete structures of 45%, while 25% was considered for steel structures and the remaining 30% for structures from other materials and for geotechnical structures. Contemporary developments of concretes with improved durability and mechanical properties suggest that concrete will retain its leading role in the near and mid-term future [17]. It is obvious that enhanced technologies and approaches to designing and/or assessing concrete structures need to be sought and developed.…”

A levels‐of‐approximation approach to seismic design or assessment of beam‐column joints in shear

“…For instance, in seismic design or assessment the shear capacity of joints should be determined with models and rules consistent with the general ones in the code concerning ultimate limit state design of one‐ or two‐dimensional elements in shear 11 . Concerning the emerging fib Model Code 2020 in particular, 12 shear strength models for seismic design of joints should follow the example of proposals for seismic design of prismatic members in shear, in a way consistent with the general design approach of the Model Code or Eurocode 8 for static actions and monotonic loading 13,14 . Such an attempt for joints is made here, following the Levels‐of‐Approximation approach 15 …”

Cyclic shear resistance for seismic design, based on monotonic shear models in fib Model Code 2010 and in the 2018 draft of Eurocode 2

“…Its results may be used in the upcoming Model Code 2020 of fib for seismic design or assessment of prismatic members in shear.…”