Influence of cationic polymer on the floccule size of cement pastes containing polycarboxylate superplasticizer and Na-bentonite

Influence of cationic polymer (KN) on the floccule size of cement pastes containing plycarboxylate superplasticizer (PCE) and Na-bentonite was studied. The proportion of floccule size and grain size \({d}_{f}/{d}_{g}\) was obtained from a rheological analysis with the application of Herschel–Bulkley model and modified Krieger–Dougherty model. Herschel–Bulkley model was used to gain the yield stress according to our previous study. Cement pastes were investigated both at the beginning and after one hour. The results showed that a high value of \({d}_{f}/{d}_{g}\) was noticed under low shear rate range and then the proportion decreased with the increase of shear rate. For cement paste containing PCE and Na-bentonite in the absence of KN, larger floccule was formed due to the intercalation of polyethylene glycol branch chain of PCE into the interlayer space of Na-bentonite. However, the floccule size of cement pastes obviously decreased with the increasing addition amount of KN. Thus, KN will restrain the formation of floccules in cement pastes containing PCE and Na-bentonite to a certain extent.