Study On The Electrical Resistivity Of The Hardened Cement Paste During Cement Hydration

As the most major component of concrete, the hydration extent of cement isdirectly related to the durability of concrete and the safety of the constructionstructure. Due to the different hydration reaction rates of various components incement, the contents of the hydration products change greatly which creats greatinfluence on the microstrcuture and mcro-performance of the cement. In this paper,the electrical resistivity variation of hardened cement pastes in different hydrationages of clinker was studied, and then to investgate the process of the selectivehydration of cement, in order to find out the relationship between the electricalproperties, compressive strength and microstructure of the cement.In this paper, in the first place, the electrical resistivity variation of hardenedcement pastes in different hydration ages of clinker was studied. In the second place,the feasibility of different test methods, such as DTA, IR, XRD, compressivestrength, to investigate the hydration extent was verified through experiments.Because the type and content of gypsum are different, the electrochemical andmechanical properties are various in different hydration ages. Moreover? thedissolution rate of the gypsum is connected with the rate of cement hydration.Therefore, it is concluded that there is a optimal dosage for each kind of gypsumwhich can contribute to the process of the cement hydration. Except for the singlefactor, the influence of the compound gypsum is further studied. Compared withformer conclus ion, the reaction rate of cement hydration is faster in the compoundgypsum system.The effect of fixed amount dihydrate gypsum coupled with different mineraladmixtures has also been studied. The results indicate that on one hand, there is aconnection between the electrical resistivity and the compresive strength of thecement paste. On the other hand, there is an optimal dosage in cement-mineraladmixture system.In this paper, the relationship between the electrical properties, compressivestrength and microstructure of the cement is established. Therefore, there is asignificant meaning in the improvement and application of cement hydration inconstuctions.