tunnelling-journal (1)
tunnelling-journal (1)
  • Home
  • Print
    • Subscribe
    • Tunnelling Journal
    • Breakthrough
    • ITA Activity Report
    • A&NZ Journal
    • WTC Preview
    • Media Kit
  • Digital
    • Newsletter
    • E-Shots
    • TJ Digital edition
    • Products Page
    • Media Kit
  • Conferences
    • BTS Conference and Exhibition
    • Cutting Edge 2023
  • Buyer’s Guide
  • Events Diary
  • Jobs
  • About Us
  • Contact Us
  • Podcast

Home > Ultra-high strength sprayed concrete challenged

Ultra-high strength sprayed concrete challenged

Tris Thomas

Written by Tris Thomas on 14/09/2017 in News

Tagged: underground

Some projects in the Middle East are using ultra-high strength sprayed concrete which reaches strengths of 80 to 90 MPa after 28 days, according to Benoit de Rivaz, global tunnelling manager at Bekaert Maccaferri Underground Solutions. The high-strength concrete, selected for its durability and early demoulding performance, requires higher and higher strength fibres.

De Rivaz was speaking at Bekaert Maccaferri’s third UK Underground Solutions seminar, which was held at the Institute of Mechanical Engineering in London’s Westminster. Ross Dimmock, technical director – Global GCCT at Normet and an attendee at the seminar, challenged the idea that higher strength was better, pointing out that harder concrete creates more rebound, more wastage and potentially more problems with banding and lamination.

Very high early strength concrete is being specified in a bid to reduce the risk of concrete falls which is leading to high 28-day strengths. But there was general agreement that there are many reasons for concrete falls and a suggestion that the requirement for very high early strengths may be counter-productive.

The day-long seminar included an explanation of the American Concrete Institute’s latest guidance on fibre-reinforced concrete segments, ACI 544.7R-16 Report on Design and Construction of Fiber-Reiforced Precast Concrete Tunnel Segments from Mehdi Bakhshi, senior tunnel engineer at Aecom. Attendees also heard the latest on SMUTI (strength measurement using thermal imaging) from Inbye MD Benoit Jones, and learnt about the use of TIM (tunnel information management) on London Underground Station upgrades from Ken Spiby and Matthew Breeze of London Bridge Associates.

Richard Foord, project manager for underground construction UK & Ireland at BASF, took the audience through lessons learned about sprayed waterproofing and Rene Wollmuth, sales manager at VMT explained his company’s semi-automated lasertracker system for checking mould and segment dimensions

Comments:

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

  1. Jaco Molenaar says:
    14/09/2017 at 3:31 pm

    we can deliver the concrete spacers in requestet stronght where thay need

    Reply

Search

Digital Edition

More Like This

31/07/2023

HS2 London tunnelling passes one mile mark

HS2 London tunnelling passes one mile mark

HS2’s first two TBMs in London, Sushila and Caroline, have completed the first mile (1.6km) of twin bored tunnel in…

22/08/2023

PUB completes tunnelling on DTSS Phase 2

PUB completes tunnelling on DTSS Phase 2

PUB, Singapore’s National Water Agency, has concluded tunnelling works on the second phase of the Deep Tunnel Sewerage System (DTSS)….

18/08/2023

Robbins Single Shield completes Turkish Rail tunnel

Robbins Single Shield completes Turkish Rail tunnel

June 2023 saw an 8m diameter Robbins Single Shield complete its second tunnel on Turkey’s Bahçe-Nurdaği Railway. The machine completed…

  • Contact Us
  • Media Kit
  • Magazine Archive

Newsletter

The latest from the Tunneling Journal direct to your inbox.

Social



Enquiries

TGS Media Ltd
The Old Library
Webster House
Dudley Road
Tunbridge Wells
TN1 1LE
United Kingdom

© Tunnelling Journal. All Rights Reserved. Privacy Policy / Terms & Conditions. Admin

We use cookies to ensure that we give you the best experience on our website. If you continue to use this site we will assume that you are happy with it.OkRead more