ITAtech publishes new segment guidance

1 September 2015


GLOBAL – The ITA Committee for Technology (ITAtech) has recently published a ‘draft’ guideline for the design of precast fibre reinforced concrete segments. Tunnels and Tunnelling understands that some internal politics is responsible for the draft label, but that it is in effect a finalised guideline.

The document provides an overview of the recommended design of tunnel segments with either steel or macro synthetic fibres. The introduction to the document adds: "The first draft document has been written to assist tunnel designers, contractors and owners in understanding the benefits of and limitations in the use of fibre reinforcement for precast concrete segments for tunnel linings, installed using tunnel boring machines. Guidance is also provided on specifications and testing.

"Further information will become available in 2016 when ITA Working Group 2 « Research will issue a publication titled 'Twenty Years of FRC Tunnel Segments Practice: Lessons Learnt and Proposed Design Procedure'."

ITAtech also said it hoped to receive feedback on the document to help keep it up to date and demonstrate what constitute good practice in the field of FRC.

Elasto Plastic Concrete's Geoff Sedgman said: "Personally I think the official recognition of both steel and macro synthetic fibres as approved reinforcement systems was a strong step forward for the industry as a whole. It would make an excellent feature in any magazine."

Lead author, Mott MacDonald's Christoph Eberle added: "We are delighted to present the outcome of several years of work by fibre reinforced concrete (FRC) practitioners to the engineering public. Over the last few years, FRC has become the standard material for pre-cast concrete (PCC) segments in several regions of the world, despite the absence of a design standard. This design guide is intended to contribute to a common understanding between the mechanical behaviour of FRC and the appropriate design of PCC segments made from this material. It is to be used concurrently with design standards or reference documents, of which the fib Model Code 2010 is a very prominent source.

"Naturally, the document represents a snapshot in time whereas a great amount of research and committee work leading to new design standards is currently ongoing. We therefore consciously took the decision to go ahead issuing a draft revision of this document to invite comments from the wider FRC design community, which we hope will lead to the document reflecting the latest understanding of the concepts behind FRC design and specification. This comment process will lead to an updated final revision of the document, while concurrently we will start drafting the complimentary production part of the guideline."