The Effect Of Nanomaterials On The Hydration And Properties Of Cement-Based Materials

The properties of cement-based materials is closely related with its microstructure.Micron grade of admixture can only optimize the composition of micron grade in cementbased materials.Nanomaterials can largely improve the innernal pore and nano gel structure of the cement-based materials.For nanomaterials,Nano silicon dioxide(NS)is with pozzolanic effect,Nano titanium dioxide(NT)is not pozzolanic effect,both of two will be benefit to the macroscopic properties of cement-based materials.Large dosage of nanomaterials may be negative influence on cement-based materials.In this paper,how NS and NT influence the mechanical property in the case of small dosage of nanomaterials will be studied,the role of nanomaterials in the process of cement hydration will be studied.The main researches of this article can be as follows.Firstly,the selected NS and NT were represented,and chosing a way to disperse nanomaterials.The effect of nanomaterials on the workability of cement paste was explored.Then the effects of nanomaterials on the mechanical properties of cement paste and cement mortar were studied in different ratio of water to binder and different dosage,the optimal amount of nanomaterials was found.The results showed that,the content of nanomaterials could increase the apparent viscosity of cement.The higher the dosage,the greater the apparent viscosity.The apparent viscosity of cement paste with NS was greater than that with NT.The results of compressive strength of cement paste and cement mortar showed that the optimal dosage of NS was 1wt% and the optimal dosage of NT was 0.1wt%.Secondly,the microstructure of cement-based materials was studied with two kinds of nano materials by the method of XRD,scanning electron microscope,EDS,TG-DSC,MIP and the experiment of heat of hydration.The results showed that,the XRD experiment showed that nanomaterials could not generate new hydrated products.The results of scanning electron microscopy showed that the nanomaterials could dense the microstructure of C-S-H.The results of TG-DSC demonstrated the nanomaterials could improve the hydration of cement-based materials,NS would reduce the amount of the calcium hydroxide(CH),and NT would increase the amount of the CH.The MIP tests indicated that the pore size distribution of the cement paste was optimized by adding nanomaterials.The results of heat of hydration showed that the application of nanomaterials could improve the hydrated reaction of the cementLastly,the rate of cement hydration was observed through the optical microscope.The appearance of the early products of the cement was studied by scanning electron microscopy.The effect of nanomaterials to the dissolution of ions in the process of cement hydration was investigated through ICP experiment.The results showed that,the rate of cement hydration could be increased by nanomaterials.And the nanomaterials could change the products of cement hydration to a certain extent.At the same time,nanomaterials could improve the ability of calcium ions to solve.