Research On The Mechanics And Durability Of Vitrified Beads Insulation Mortar

With the development of society, people attach more importance to the issue of the building energy efficiency. The building insulation materials and system are come to the fore. The glass bead is a kind of inorganic insulation materials with excellent performance. Although it more applied to the construction, it also has some defect to improve. This thesis mainly talks about cement-based glass bead thermal mortar. This thesis researches the components’ effects on it and its durability and improvement measures by orthogonal test and single factor experiment.The experiments indicate as below: Four elements have the great influences on glass bead thermal mortar, which are aggregate, the amount of re-dispersible powder,the rate of the cement changing to fly ash and the water cement ratio. According to the different property of thermal mortar, their influences are different. In order to get its best mix ratio, we must synthesize the relevance between each element and then find out the main element.As the additive, the re-dispersible powder and cellulose ether can make great improvement on glass bead thermal mortar. The former can increase the consistence of mortar, the compressive strength and its dry density. The latter has good function on water retention and air entraining. It can increase the workability of thermal mortar and decrease the dry density. It is good for construction. But these can work only when adding the appropriate quantity of cellulose ether. If it’s not, when the consistence is oversize, it will get bad impacts on construction.We get the best mix ratio of glass bead thermal mortar by the two experiments.The amount of glass bead takes up 28.5 percent, the re-dispersible powder 2 percent,the cellulose ether 0.5 percent, polypropylene fiber 0.45 percent, the rate of the cement changing to fly ash 20 percent and the water cement ratio 1.7 percent.We tried to add different kind fiber in glass bead thermal mortar, and investigated their different influence. The fiber can promote the flexural strength. It can also decrease the air shrinkage and the ratio of bending strength to compressive strength,which are beneficial to the durability of thermal mortar. The fiberglass gets good effect on improving the compressive strength and linear shrinkage. The polypropylene fiber gets more effect on flexural strength. When we add different length fiberglass inthermal mortar, the fiberglass in 3 mm are better than those in 6mm. The fiber can promote the impact resistance. With the increase of the fiber’s amount, the mortar will be broken and then it will result in “Brittleness”. When the amount of polypropylene fiber gets to 0.15 percent, the impact resistance becomes the best.On the condition of the heat raining cycle and the freeze-thaw cycle, it will bring great quality reduction and strength reduction to glass bead thermal mortar. The bad effects caused by the latter one are more than the former one. When we took the hydrophobic treatment on the glass bead thermal mortar, the quality reduction and strength reduction will decrease a little when compared with general thermal mortar,but the impact was not very obvious.