Adsorption kinetics of retarding admixtures on cement with time controlled addition

For sodium gluconate, an interaction with ferrite containing clinker phases and a calcium complexing mechanism were suggested. In contrast, EDTMP seemed to have no significant influence on the calcium concentration. With regard to the sodium concentration a fast adsorption of sodium gluconate was determined. Furthermore, a competitive adsorption between dissolved sulfate and retarder molecules or a complex formation mechanism is supposed.