Effect Of Redispersible Latex Powder And Fly Ash On Mortar Performance

With the development of science and technology,admixtures and mineral admixtures play an increasingly important role in cement mortar,It significantly improved the related defects of the mortar.To determine a certain proportion of cement mortar,making it less in strength,and has good workability,cohesiveness,shrinkage,frost resistance,etc,experiment on the joint action of fly ash and dispersible polymer powder in cement mortar,fly ash is mixed with cement by equal mass,and the dispersible polymer powder is incorporated as a percentage of the mass of the cementitious material,study on the effect of its influence on the properties of mortar mixture and mechanical properties of cement mortar,combined test results,analysis of the influence mechanism on the properties of mortar mixture and mechanical properties of cement mortar,the results show:(1)20%fly ash in cement mortar,improved the consistency and water retention rate of cement mortar,increased the setting time of the mortar,positive effect on the water absorption rate of the mortar,increased tensile bond strength,conducive to the development of cement mortar late strength.(2)20%fly ash in cement mortar,it reduces the frost resistance of the pre-production cement mortar specimens,and is mainly beneficial to the frost resistance of cement mortar specimens in the late maintenance.Simultaneously,reduced shrinkage of cement mortar,the shrinkage rate tends to be stable in the late maintenance.(3)With the increase of the amount of redispersible latex powder,consistency,water retention rate,condensation time are increased,increased flexural strength and tensile bond strength,water absorption rate,compressive strength,and compression ratio are reduced,relative to cement mortar mixed with 20%fly ash,when the amount of redispersible latex powder is 3%,its consistency,water retention rate,and setting time are increased by 34.21%,9.76%,and 57.89%.,28 days of flexural strength and tensile bond strength are increased by10.06%and 74.89%,28 days of water absorption rate,compressive strength,compression ratio,thermal conductivity are decreased by 13.02%,31.17%,37.54%,15.15%.(4)With the increase of the amount of redispersible latex powder,improved the frost resistance of cement mortar.Simultaneously,to some extent,the shrinkage rate of cement mortar is inhibited,and with the growth of maintenance age,the polymer film formed by dispersing the latex powder particles in the cement mortar is substantially completely formed,shrinkage tends to be stable.(5)In order to explore the mechanism of dispersible polymer powder on cement mortar,establish a basic model for its reaction stage in cement mortar,and a model of the adhesive interface,at the same time,in order to reflect the change of compressive strength with the freeze-thaw cycle of cement mortar,established a calculation model:f~/=f[1-(0.01N-0.22)].