Event report: Developments in Structural Concrete, 6 November 2013
Inaugural fibUK seminar hailed a success, covering off-site manufacture, service life design, shear in beams and concrete cable stayed bridges.
fibUK held a seminar on 6 Nov 2013 at the Institution of Structural Engineers HQ in London. This inaugural seminar provided practitioners and academics with a valuable update on developments in the design and construction of structural concrete. The event featured eminent practitioners speaking on subjects from off-site manufacture to service life design, and recent technical developments to practical case studies.
Prof. Steve Denton, fibUK chairman and Engineering Director at Parsons Brinckerhoff, opened the afternoon with an explanation of fib’s contribution to the practising engineers, especially on Model Code 2010 which is the latest updated edition to the Eurocodes. He welcomed the new members and extended his invitation to others including universities, consultants and contractors reiterating the benefits of being a member of the UK group.
Laing O’Rourke’s Dr. John Stehle discussed the off-site manufacturing processes at its factories in Worksop (Explore Industrial Park) and Swadlincote (Bison) and showed examples of hollow core slabs, load bearing facade panels, twin walls, lattice slabs, platforms, bridge beams and shell beams. He presented two case studies: one of water retaining twin walls in water tanks and the other of light weight concrete planks at the Leadenhall Building in London. The complexities in design and construction issues were overcome by Laing O’Rourke’s one team approach with their own design guides in-line with relevant codes.
Professor Tom Harrison, consultant and visiting professor at Dundee University, described the challenges and limitations on serviceability design to corrosion by carbonation, chloride induced and chemical attacks. He showed the differences from comparing the current requirements from the fib model code, ISO16204 and Eurocodes. EN206 and EN1992-1-1 may include new conformity requirements for exposure classification in the proposed new revision in 2020.
The current fib president, Gordon Clark (director at Ramboll) briefed the audience on fib activities including the publications, congresses and symposia, PhD symposium, proceedings and international events across the globe. He also summarised the history of the formation of fib and its achievements in the past.
Prof. Steve Denton summarised the first half of the seminar followed by Q&A session with the audience.
The second session began with the proposed improvements to the 'Ease of use of Eurocodes – a vision for the future' by Prof. Steve Denton. He demonstrated the structure and the committee details of the new CEN/TC250 commission which formed to work 'towards the second generation of Eurocodes' by 2020. He has also mentioned that the fib model code 2010 will be the primary reference for EN1992 and greater harmonisation (i.e. reduced NDPs) in the new set of revisions.
'Shear – Common sense or shear nonsense' was presented by Dr. Tony Jones of Arup, and he covered the recent changes in beam design and its impact on designs with his own view on areas for improvement. He illustrated the shear reinforcement against shear stress for variable strut inclinations and compared this against traditional Vc+Vs. He discussed the effect of pre-stress on shear (benefit/loss) comparing EN1991-1-1 to the model code and identified this as one of the areas for improvement along with shear for circular sections.
David MacKenzie from Flint & Neil argued that the recent developments in concrete cable stayed bridges would be an economic alternative to other materials, e.g. steel. He described the pros and cons for different types of solutions with real examples and explained the contribution by the model code in bridge designs.
Questions and discussions followed at the end of second half. Over 70 delegates from various sectors of the industry attended and the seminar was well received by everyone. Every guest received fib’s complementary pack which contained a copy of the presentations, an extract from the draft model code 2010, bulletin 34 and the June 2013 fib journal. The chairman closed the seminar by leading a warm round of applause.