Ann: CDOT Central 70 Project Update, page-115

From my experience with working with fibres in concrete (and we use a lot of different ones: stainless melt extract, polypropylene macro, polypropylene micro, AR fibreglass), the macro fibres disperse readily whilst the micro ones take a lot more mixing. Presumably the smaller and finer the fibres the greater the dispersion problem so nano fibres take even longer than the micro fibres. EDE recommend 70 revolutions of the mixer after Edencrete addition as well as some minor agitation of the concentrate before decanting the measured dose, no doubt to ensure adequate dispersion that I'm sure they would have tested adequately..