Liran Zhang;Dongmin Wang;Weili Zhang;
<正>The changes of free water amount,rheological properties and electrokinetics of cement paste were examined by varying superplasticizers added to the cement paste,while different types of grinding aids were used in the cements production mentioned above. The flocculation-dispersion situation of cement particles and hydrated cement particles in fresh cement paste was explained with the theory of multi-level flocculation structure of fresh cement paste.The alteration of free water amount and electrokinetics,as well as their effect on the rheological characteristics of fresh cement paste was studied The results show that the grinding acids have great influence on the compatibility of cement-superplasticizer system,including the thixotropy,the fluidity and the time-depended fluidity loss of cement paste.The grinding aids added(the powder grinding aids,traditional liquid ones and novel ones) lead to the changes of charge distribution of cement particle surface or cement hydration process,including the modification of the multi-level flocculation structures.These changes directly effect the effectiveness of superplasticizers,which leads to different compatibilities of the superplasticizers-cements system. Originality: In the paper,the compatibilities of the superplasticizers-cements system were analysed by the theory of multi-level flocculation structure.The theory established the organic connection between the microscopic structures and macroscopic properties,and opened up a kind of new research methods and ideas for superplasticizer - cement field.The influence of grinding aids on the compatibility of superplasticizer - cement system were examined from free water amount,rheological properties and electrokinetics of cement paste.And then the interaction among cement particles and the charge properties of the particle surface were studied in detail.The paper elaborated the mechanism of influence of grinding aids on the compatibility of superplasticizer - cement system.
compatibility;;superplasticizer;;rheology;;grinding aid;;multi-level flocculation structure
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