Holdfast Training Services Trial Blog

Sadly E&Ms this is one for the Civils but feel free to read if you want.

This week I was asked to assess a contractor’s proposed concrete repair procedure for precast concrete road barriers (similar to the central reservation barriers on the M25 or M6).

A repair procedure was required because the end stops had slipped during the pour resulting in 10-15mm excess cover at the ends of the barriers. The contractor’s proposal was to saw-cut or grind the concrete back to the design cover so the barriers met the precast dimensional tollerances. Having seen this done on phase 2 site for in-situ patch and crack repairs, I thought it was a reasonable proposal providing adequate H&S measures are employed.

After checking the project specifications for concreting and precasting I found no reason to reject their method. Prior to approving the Contractor’s RFI, a senior engineer reviewed my work and insisted that 3mm (min) of Megapoxy P1 mortar repair grout must applied to any cut or ground surfaces. He explained this is done to the ends of precast super T beams when they cut the prestress strands as 3mm of Magapoxy P1 equates to 50mm of cover.

I can understand why this is done on the super Ts however the road barriers have standard reinforcement (no strand) so is there really a need to apply Megapoxy in this case? I challenged the decision on the basis that it may not be required as that the original design cover would be maintained. In my view the Megapoxy P1 requirement is a potentially unnecessary cost (time and money) to the contractor. I was told if the contractor doesn’t like it they will let us know…

Megapoxy P1 TDS

Does anyone have any previous experience of this? Is this another case of ‘this is what we’ve always done’ or is there another good reason to apply a layer of repair mortar?