PFA exchange wins on paper
THE CONSTRUCTION industry should make better use of the 5Mt of wet pulverised fly ash wasted each year in the UK, according to Dundee University student Stuart Menzies.
He was this years winner of the Dundee branch papers competition, held earlier this month. Menzies claimed that up to 15% of the sand used in concrete manufacture could be replaced with PFA.
Although BS3892 Part 1 1997 does not allow the use of PFA as a replacement for cement, Menzies said that Part 2 1996 allows the use of wet PFA as an inert fill if it has a moisture content greater than 0.5%.
Research by Menzies for his honours project had demonstrated that substituting 15% of the sand in concrete test cubes resulted in an increase in strength at 90 days and a reduction in permeability, with only a small loss of work-