Study On Engineering Properties Of Nano CaO Cement-stabilized Soil

Cement-stabilized soil is widely applied to all kinds of soft soil reinforcementengineering because of the convenience, less influence on the surroundingenvironment, low price and notable strengthening effects.Mixing the soft soil andcement will get the cement-stabilized soil, it has integrity, low compressibility andwater stability. But later proved that the cement soil strength is not high and the largedeformation so in many applications it will be limited. If simply increase the quantityof cement is unreasonable in terms of economy and construction technology, so thechoice of suitable additives has important significance to improve the strength ofcement soil.In this paper, based on the excellent performance of nano materials, the nanoCaO is mixed into cement soil, through orthogonal test and comprehensive testanalysis the of unconfined compressive strength ratio change with nano CaO cementsoil in different cement ratio and different nano CaO doped. After different agecuring, through the acoustic test to observe the changes of velocity. Based on theanalysis of SEM, the microstructure characteristics of cement soil and nanoCaO cement soil can be get. Through the analysis of stress strain curve nanoCaO cement soil Intensity change can be understood. After all the tests, conclusionscan be gained as follows:(1)In the orthogonal design tests found that the cement content is20%, the nanoCaO mixing ratio is10‰, the water cement ratio is0.35when the cement soilunconfined compressive strength is the highest, this combination is the best ratioof orthogonal design.(2)Through comprehensive experiments on four cement ratio when the content ofnano CaO was10per1000in the same curing age the maximum unconfinedcompressive strength is the highest, reliability is also verified that the design oforthogonal test results. (3) By means of scanning electron microscope，large pores of the cement soiland nano CaO cement soil are less than undisturbed soil, the structure is compact. Asthe same time, the small pore in nanometer CaO cement-soil is less than purecement-soil.(4) The stress-strain relationship of soil cement mixed with nano CaO rise timelike curve slope elastic deformation stage and the curing time and cement mixingratio of the slope.(5)Through the fitting relationship between deformation modulus andcompressive strength the formula of cement soil is:E50=64qu,while nano CaOCement-stabilized Soil is: E50=73qu.