Study Of Dry Mixing Ordinary Mortar Admixtures

Dry mortar quality depends mainly on chemical additives and inorganic mineraladmixture, which we are currently focusing are difficult. At present, the dry mixedmortar additives are widely used in high range water reducing agent, water-solublestarch and cellulose derivatives, dispersible polymer powder, these additives atpresent levels of study, while not as well-known foreign companies, but has been abreakthrough on the key technologies, to meet the requirements of industrialproduction. And also, dry mixed mortar additives have been widely used mineraladmixture of fly ash, slag powder, limestone powder, silica fume and perlite.The cement mortar as a cementing material, to be used of diatomaceous earthand hydroxypropyl methyl cellulose as water retention thickening admixture,selection of fly ash, granulated blast furnace slag, zeolite powder three differentmineral admixture single doped and blending, in order to get the best content andratio, based on national regulatory requirements, further reducing costs.Test for diatomaceous earth and hydroxypropyl methyl cellulose (HPMC) aswater retention thickening admixture of cement mortar were studied. The results areshowing that diatomaceous earth or cellulose ether as water retention thickenerrespectively mixed with dry mixed mortar, the workability of the sample showedsignificant improvement, but there are also have some disadvantages, those aredoping diatomaceous earth, diatomaceous earth dosage of unilateral waterconsumption, water retention lower than HPMC; doping HPMC, the mortar can beoperational performance, but higher dosage of air-entraining serious greatly reducethe strength of mortar, and the price more expensive, to some extent increasedmaterial costs. Therefore, to ensure that mortar various aspects of performanceindicators can meet the specification and construction requirements, to mixeddiatomaceous earth and HPMC within a certain percentage will be much better.The fly ash, granulated blast furnace slag, zeolite powder on the mechanicalproperties and durability of cement mortar impact. Fly ash mortar specimenscompared with the unincorporated mineral admixtures blank group specimen agestrength is low, and the strength index shows a linear trend with increasing fly ash content, durable in terms of the incorporation of fly ash effectively improve the frostresistance of mortar specimens, but impermeability test results are not perfect. Mixedwith granulated blast furnace slag mortar early strength of the sample were lowerthan the incorporation of mineral admixtures blank samples of group, and itsintensity linearly downward trend with increasing dosage, but late strength generallyhigher; durability, the incorporation of granulated blast furnace slag are greatlyimproved frost resistance and impermeability of mortar specimens. Mixed withzeolite powder mortar early strength of the sample is slightly reduced, but onlyslightly, with the growth of the age, with different contents of the zeolite powdermortar28d strength more than blank group mortar unincorporated mineraladmixtures; in terms of durability, the zeolite powder mortar poor specimen frostresistance, impermeability of mortar samples mixed with zeolite powder slightincrease the seepage height slightly lower.Re-mixed cement mortar performance of fly ash and granulated blast furnaceslag two mineral admixtures, analysis of different proportions of the complex dopedmortar in each performance are better than not mixed with mineral additives thematerial blank group as well as the single-doped mineral admixtures mortar sample.Fly ash and granulated blast furnace slag Two admixtures in the process of mixingthe morphology complementary, during hydration process complementary, fullyembodies the advantages of "super-additive effect".By very poor analysis of orthogonal design discusses the marking of cement andmineral admixture dosage, water-retention and thickening agent volume three factorson compressive strength of mortar specimen for impact.By scanning electron microscopy group of fly ash and ground granulated blastfurnace slag admixture ratio analysis the micro-structure of the specimen, fly ash andground granulated blast furnace slag particles are covering a lot of needles hydrationproducts, and that they showed good gradation between the particles, their strengthhas been greatly improved in the end.