Study On The Effect Of Adding Cellulose Ether And Calcium Stearate On Chinese Traditonal Lime

There are rich cultural values and historical significance behind every ancient city wall,which is of great significance for inheriting the 5,000-year historical civilization of our country,and even related to the inheritance of national culture.However,mortar in a large number of existing masonry structures is seriously damaged.Therefore,the mortar repair work has important historical and practical significance.Nowadays,Portland cement replaces lime-based cementitious materials for repair work,causing many problems: different chemical composition from original lime-based cementitious materials,high brittleness,low permeability and high elastic modulus.Therefore,it is necessary to use the original pure white lime for repair work.First of all,this paper modified the white lime commonly used in ancient China,aiming at improving its deformability,strength ductility and water resistance..In this paper,hydroxypropyl methylcellulose(HPMC),calcium stearate(CS)and glutinous rice pulp(SR)were added to the white lime commonly used in ancient China to explore their effects on the physical and mechanical properties of lime.At the same time,the influence of different dosage and calcium hydroxide content on lime is considered.The experimental results show that when the content of HPMC and CS is 0.3%,the physical properties of lime with high calcium hydroxide content are good,and the flexural strength,water resistance and strength ductility of lime after immersion are improved.In the lime with low calcium hydroxide content,the comprehensive properties of lime with hydroxypropyl methylcellulose are poor,and when calcium stearate(CS)is 0.3%,the physical properties are good,and the flexural strength and water resistance,strength ductility after immersion,and flexural strength and toughness of lime after immersion are improved.Then,multivariate statistical method(factor analysis method)is used to analyze the experimental results,thus simplifying the analysis process of lime performance.By constructing a few factors to describe various properties of lime,the performance differences of different lime groups are visualized,which is beneficial to the performance comparison among different limes.Finally,a multivariate regression model is established,and a bivariate model is established considering the dummy variables such as lime admixture types.The composition of lime is related to the performance of lime,and the correlation between different factors can be quantified.The established compressive strength model after immersion identifies and quantifies the relationship between lime weight loss rate,water retention,admixture,cementitious material and compressive strength after immersion.The relationship between consistency value,admixture,cementitious material and the ratio of compression to fold after immersion is identified and quantified by the strength model of ratio of compression to fold after immersion.