Influence of mechanical activation of fly ash in presence of polynaphthalene sulfonate superplasticizer on rheology and hydration kinetics of cement – fly ash pastes

•Fly ash is milled in two modes: with PNS superplasticizer and apart of it.•Presence of PNS prevents adverse agglomeration of the fly ash particles.•Pastes consisting fly ash milled with PNS exhibit enhanced rheological properies.•Evaluated influence of PNS and fly ash on hydration kinetics of the blended binder.