The British Standard for the structural use of concrete is to be replaced with Eurocode 2 in March 2008. But there’s no need to worry, says The Concrete Centre’s Charles Goodchild
It could cost the typical 16-man consulting practice £250,000 to change from British Standards to Eurocodes. So says a report by the Institution of Structural engineers, which underlines the need for the construction materials sectors to help with the transition to the new codes.
The report, National Strategy for Implementation of the Structural Codes: Design, found that the greatest cost will be a 10% loss of productivity during the first year, as staff get used to the new codes. This could cost the firm as much as £128,000.
Despite the initial costs, however, there will be economic benefits to be derived from using the codes. In concrete design, it is expected that there will be material cost savings of 5% compared with BS 8110. Furthermore, Eurocodes are less restrictive than British Standards: they are logical and organised to avoid repetition, are technically advanced and should provide more opportunities for UK designers to work in Europe – and for Europeans to work in the UK.
In common with all European Union countries, public authorities will have to accept Eurocode 2 (EC2) as a valid method of design on large works. In the UK, the concrete sector is one of those leading the way in the transition, with the publication of its UK national annexe in December 2005. This means that, with the exception of bridges and water-retaining structures, it is now possible to design structures to EC2.
The Concrete Centre is working with the construction industry to provide a range of resources that will make the transition to EC2 as simple as possible. A website, www.eurocode2.info, provides advice and assistance on the introduction, interpretation and implementation of EC2. And the centre is also putting on a series of seminars and courses on EC2 across the UK, as well as publishing a series of guides under the banner How to Design Concrete Structures Using Eurocode 2.
The guides aim to make the transition as easy as possible by drawing together the key information and commentary necessary for the design of typical concrete elements, such as slabs, beams, columns and so on. The Concrete Centre has also published a Concise Eurocode 2, which cuts through all the relevant Eurocodes and UK national annexes to give simple guidance on how to design concrete building structures to Eurocode 2. A book of worked examples and publications on civil engineering subjects such as integral bridges will follow.
The main thrust of Concise Eurocode 2 is to put the requirements of Parts 1-1 and 1-2 of Eurocode 2 into plain English and a logical order. It starts by explaining the basis of design, materials and analysis, before dealing with the phenomena of bending, axial force, shear, punching shear, torsion and serviceability, as per the code. Detailing, tying and plain concrete are also covered, and the guide contains an extensive section of design aids (including tables and charts for shear, deflection and column design).
The guide explains the relevant parts of Eurocode (basis of design), Eurocode 1 (actions) and Eurocode 7 (geotechnical). In addition, Concise Eurocode 2 offers derived data that provides significant assistance to those designing to the new code.The other parts of Eurocode 2 work as a set of exceptions to the clauses in Parts 1-1 and 1-2, so a thorough understanding of Parts 1-1 and 1-2 will be prerequisite for designing concrete bridges and liquid retaining structures.
As a sector, the concrete industry welcomes the new code. They are the culmination of more than 40 years of development and will offer a rational and reliable basis for design. Furthermore, the concrete Eurocodes are relatively simple to digest and use, as they consist of only four parts and four national annexes; steel has 21 parts and as many as 59 national annexes.
There is already a comprehensive range of resources to help designers and engineers familiarise themselves with the new concrete code. Their availability, plus that of the concrete national annexes, begs the question, why not do it in concrete first?