Canterbury Technical Forum Meeting
5.30pm – 7.30pm, Wednesday 3 April 2013
Lecture Theatre E8, College of Engineering, University of Canterbury
The Forum meeting was chaired and summariesed by Bruce Deam on behalf of the NZ Society for Earthquake Engineering. Click on contributor's names to send them an email message.
Steve Gerrard (Concrete Connect) provided an excellent overview of the techniques used to repair cracks in concrete using epoxy injection. Steve's presentation outlined the key aspects required to design and implement a repair, based on both European guidelines and 30 years of practical experience. The first part compared capabilities and limitations of the low pressure equipment and hardware and high pressure epoxy injection. Steve then described the surface preparation, injection packer placement and epoxy viscosities required to balance resin penetration and overflow in various crack widths, indicating that the controlled (high) pressure injection equipment provides the best quality control with proven results. He outlined many practical details, many from his post-earthquake repair and international training experience, techniques to repair failed injection. He concluded that in the absence of both standards and approved procedures, core testing provides the only practical quality assurance giving immediate visible proof of the success of the repair.
Steve answered several questions and can be contacted by email (steve@concreteconnect.co.nz) to learn more about concrete injection and repair. Steve's Presentation
Dave Brunsdon (MBIE Engineering Advisory Group) outlined how the EAG focus had been on training since the release of the revised guidance in January, but there is further technical information being prepared for both the residential and light commercial/industrial sectors. He indicated that with a focus on consenting, the standard of documentation still needs to be improved, especially for residential work, with clear summaries of the key design features needing particular attention. He outlined the contents of a typical Design Features Report that provides for both current consenting needs and future work on the property. Dave's Presentation
John Hare (SESOC) announced that the EAG had updated the Standardised report form on the SESOC web site. He outlined a methodology being developed to assess the strain elongation capacity remaining in reinforcing steel after seismic deformation. He also outlined the DEE method being developed to evaluate the out-of-plane capacity of tilt panels based on the development of their yield line patterns. He concluded by indicating that the RC Frames guidance is due out soon and that (as always) all work should be on the basis of understanding how a building responded to the ground motion and is likely to respond to future motion.
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