| With its excellent performance, thermal insulation with expanded and vitrifiedbeads represented by inorganic lightweight aggregate thermal insulation, has becomea new direction in the building insulation material development. However, due to itsporous structure and its main ingredient which are inorganic hydrophilic material, thewater resistance of thermal insulation with expanded and vitrified beads is bad. Thusimproving the water resistance of thermal insulation with expanded and vitrifiedbeads is propitious to enhance the stability and durability of its thermal insulationproperties in humid surroundings.Firstly, we studied how the quantity of aggregate affected the performance ofthermal insulation by experiments. The results showed that cementitious materialcould be sufficient to completely coat the aggregate and fill the gap among that whenthe quantity of aggregate was below40percent, which showed waterproofoptimization potential. Furthermore, the basic mix proportion of that potential wasconfirmed on the basis of the available literature and existing research results.(Cementitious material: Insulation aggregate: Redispersible powder: Cellulose ethers:Organic fibers: Water=1:0.65:0.03:0.007:0.003:1.4)Secondly, we adopted two ways to improve the water resistance of thermalinsulation with expanded and vitrified beads. One was modification insulationaggregate to hydrophobic. The other was modification cementitious material tohydrophobic. The experimental results suggested that both of the modified schemecan effectively improve the water resistance of mortar. But the way of modificationcementitious material to hydrophobic had a better performance.Finally, we made orthogonal experiment to research how the four factorsincluding cement types, aggregate species, blowing agent content and hydrophobicmodifier content impacted the water resistance and basic performance of thermalinsulation with expanded and vitrified beads. In terms of basic properties, blowingagent content and cement types had greater influence while aggregate species andhydrophobic modifier content had little effect. Specifically, the order of factorswhich influenced the water resistance of thermal insulation with expanded andvitrified beads was Blowing agent content→Hydrophobic modifier content≈Cementtypes→Aggregate species. Moreover, thermal insulation with expanded and vitrified beads had the best overall performance when the mix proportion is3%of thecomposite cement, ordinary expanded and vitrified beads and blowing agent contentand1.8%hydrophobic modifier content. |
