Experimental Study On Mechanical,Shrinkage And Durability Of Fly Ash Ceramsite Mortar

The research of fly-ash ceramsite mortar is very important in the field of lightweight concrete.Scholars at home and abroad have carried out many related researches on fly-ash ceramsite mortar,but there are still deficiencies in the adjustment,such as the research content is not comprehensive enough,the performance optimization of fly-ash ceramsite mortar is not perfect,the recycling of fly-ash is not sufficient,etc.In order to study the properties of fly-ash ceramsite mortar,promote the development of lightweight fly-ash ceramsite mortar and recycle fly-ash,firstly,different amount of fly-ash ceramsite is used as aggregate to replace river sand to prepare lightweight fly-ash ceramsite mortar,and the mechanical strength,self shrinkage,dry shrinkage,durability and high temperature resistance of the specimens under different ages are tested The influence of the content of fly ash ceramisite on the performance of mortar is studied.Then,the content of fly ash ceramisite is controlled to be the same,and different content of silica fume is added to prepare the fly ash ceramisite mortar.Through the test and analysis of the mechanical strength,shrinkage,durability,high temperature resistance,SEM and other indicators of the mortar at different ages,the improvement effect of silica fume on the performance of fly ash ceramisite mortar is studied.The conclusions are as follows:1)Adding fly ash ceramsite into mortar can reduce the dry shrinkage and self shrinkage of mortar,enhance the anti CL erosion performance of mortar,and improve the high temperature resistance of mortar,and the greater the content of fly ash ceramsite,the better the effect2)The apparent density of mortar can be greatly reduced by adding fly ash ceramsite into mortar,and the higher the content of fly ash ceramsite is,the smaller the density of mortar is.3)The compressive strength and flexural strength of mortar are reduced by adding fly ash ceramsite into the mortar,and the larger the content of fly ash ceramsite is,the greater the degree of strength reduction is,but the overall reduction of strength is smaller.When the content of fly ash ceramsite is 40%and 100%,the compressive strength of 28 day old test block is 43.23mpa and 37.25mpa respectively,which can still meet certain engineering requirements.4)Adding silica fume into the fly ash ceramsite mortar can further improve its mechanical strength,anti CL erosion performance,microstructure,reduce porosity and water absorption,and determine the best content of silica fume is 10%.5)The addition of silica fume makes the dry shrinkage and self shrinkage of fly ash ceramsite mortar increase,the larger the silica fume content is,the more obvious the shrinkage is;silica fume can reduce the mass loss rate of fly ash ceramsite mortar,the greater the silica fume content is,the more obvious the effect is.The results show that fly ash ceramsite can be used as green environmental protection material instead of natural river sand to prepare mortar with light weight,high temperature resistance,salt corrosion resistance and small shrinkage.Under certain conditions,the replacement rate can reach 100%.At the same time,the strength,Cl-corrosion resistance and microstructure of fly ash ceramsite mortar can be modified by adding appropriate amount of silica fume Good to meet specific engineering requirements.The research results of this paper are of great significance to promote the development of lightweight concrete.Figure[44]Table[10]Reference[82].