Determination of the reactive silicon dioxide (SiO2 react) of fly ash
With the introduction of the European Standards EN 450-1 and EN 450-2 for fly ash for concrete in January 2007 the reactive silicon dioxide (SiO2 react.) of fly ash from co-combustion has to be investigated regularly. This ensures the reactivity of fly ash and the positive influence of the puzzolanic reaction on the concrete strength.
To define the reactive silicon dioxide content EN 450-1 refers to EN 197-1. The methods of testing are described in EN 196-2. As some problems appeared to identify the correct procedure the attached guideline was prepared and should be used from all parties.