I was amused to read your article 'non toxic concrete treatment trialled' (NCE 1 July). The Department of Transport selected 'silane' for use more than 15 years ago.
This decision was strongly influenced by a major exhaustive study, carried out in the USA, (National Cooperative Highway Research Report 244).
Silane was selected, because it is cost effective, and has a proven, long term, effectiveness.
Pavix, the product type referred to in your article, was also included in this study. It proved to be nothing more than a solution of 'water glass'.
Long ago my grandmother used 'water glass' to preserve eggs, but the report 244 does not recommended it for the preservation of concrete.
So called 'non toxic' silanes have been available for several years, but they do not penetrate deeply into the concrete. It will be interesting to hear the results of these M60 trials.
Bryan Kennedy, manager, Silanes, Degussa UK, bryan. kennedy@degussa. com