The Brew Cabin

have to do underpinning with above strength concrete, one or two pins every 48 hours, to small for ready mix
any help please, looked at your tables for C 30, 1 1 2 figures did not seem to divide right.

I'm not preparaed to give you a 'recipe' for a 35 Newton concrete, because you should be using ready mix from a quality assured supplier (QSRMC) for something as critical as underpinning.

I would be shocked to find that any insurer or building control officer was prepared to accept site-mixed concrete, unless the concrete could be shown to meet the requirements for the work in hand by means of cube tests and the rest of the gamut of materials testing that is carried out as part of QSRMC.

My problem is that, if I give you a recipe and owt goes wrong with the mix, then I'm partly liable, and, as they say around these parts, bugger that!

Thanks Tony for such a quick reply even if what you said was not what I wanted to hear. Had a very big job done by Allied Pilling and they mixed all the concrete for the pins on site, when I asked about the quality, boo just said you can tell by how green they are. They gave us a gaurentee. our pins are to small quantities, and would be 3 trips for ready mix. Thanks again great site will give it a lot of study. I am only foreman and have to do what boss tells me.