Influence of Power Ultrasound on the hydration of C3S

• 作 者: PetersS.;R(o)βlerC.;LudwigH.-M.;
• 机 构: FA.Finger Institute, Bauhaus-Universit(a)t, D 99421 Weimar, Germany
• 出 处: The 14th International Congress on the Chemistry of Cement (
• 发表日期: 2015年期

　　Power Ultrasound is widely used in various technical processes (from pharmaceutics to ceramic and tuel industry) to disperse suspensions and to control crystallization processes.The authors of the present study have shown before that by PUS application early strength development of concrete is accelerated and thus PUS can be used to replace heat treatment in precast concrete production.The present study discusses the origin of the hydration accelerating effect of PUS.Therefore also the effect of PUS on C3S hydration is investigated.Thus precipitation of strength determining C-S-H phases under conditions of homogeneous and heterogeneous nucleation in dependence of PUS application is studied.Precipitation processes of C-S-H are followed by measuring electric conductivity of aqueous phase, ion concentration in aqueous phase and by imaging microstructural development using high resolution Scanning Electron Microscopy (SEM).The results of the present study clearly show that PUS is only effectively promoting crystallization in the case of heterogeneous nucleation.That indicates that the accelerating effect of PUS is connected to the presence of particle surfaces.