Modified Research On Vitrified Beads Insulation Mortar

The volume of vitrified beads insulation mortar bibulous rate was far lower thanthe perlite insulation mortar, fire resistance was much higher than polystyrene particlesinsulation mortar, the compressive strength of the products was relatively high, thermalconductivity was relatively low, so the market was occupied by vitrified beadsinsulation mortar quickly. Ordinary vitrified beads insulation mortar in exteriorinsulation construction process existed to some problem, such as, the product qualitywas uneven, operation was not standard, site supervision was difficult, leading to newbuildings energy saving effect was not ideal, therefore in Chongqing, Beijing and othercities vitrified beads insulation mortar had been banned from use. In view of this, on thebasis of normal vitrified beads insulation mortar, we mixed with18-20%of lime for itsmodification research, and providing the reference for making cement calcium basevitrified beads insulation mortar composite board products.By shaping curing test, the influence of mixing time, water consumption andmaintenance conditions to the properties of cement calcium base vitrified beadsinsulation mortar was determined. Through the orthogonal test, the initial mixture ratiowas determined, further optimized analysis by single factor experiment, determining theamount of120kg/m3vitrified beads was about44.5%, corresponding the best dosage ofcement (not including the dosage of fly ash) was30%~34%, the fly ash or drift beads,the optimal dosage of equivalent replacing cement was10%, the mixing amount ofwater repellent was0.1%, the content of latex powder was1.8~2.0%, the optimumcontent of hydroxypropyl methyl cellulose ether was0.2%, the best dosage ofpolypropylene fiber was0.4%, the best dosage of polystyrene particles instead ofvitrified microsphere was3%. Finally, by the optimized mix proportion test block ofinsulation mortar was made, and the test of the dry density, compressive strength,insulation, shrinkage, crack resistance, fire resistance analysis was carried on.By artificial carbonization test, mixing18-20%of lime to the special effects andfunctions of vitrified beads insulation mortar was analyzed. After preliminarycarbonization test, scanning electron microscope (SEM) was used to carry outmicrostructure scanning of the specimen, we found that the use of calcium hydroxideproducing calcium carbonate crystals to increase the density and intensity of heatpreservation mortar, the concentration of carbon dioxide must be controlled. Through changing the concentration of carbon dioxide of specimen carbonization, we found thatlow carbon dioxide concentration was conducive to the growth of calcium carbonatecrystal which could be packed by cement hydration product to densify the structure ofinsulation mortar, ultimately the favorable carbon dioxide concentrations weredetermined to be20000PPM. By XRD and EDS energy spectrum analysis, weconfirmed that cement calcium base insulation mortar carbonization generated a largeamount of calcium carbonate crystal, the calcium carbonate crystal deposition in thethermal insulation mortar of wool stoma which made wool stoma refinement and wasadvantageous to the later strength growth significantly.