Preparation And Properties Of Modified Vitrified Microsphere Thermal Insulation Mortar

With the continuous reduction of fossil energy materials and the deterioration of the environment,all countries have begun to pay attention to energy conservation and environmental protection.Under this background,China has put forward the goals of "carbon peak" and "carbon neutrality".At present,building energy consumption has become a large energy consumption,to complete the "double carbon goal" must be strictly controlled building energy consumption,to find good thermal insulation performance of wall materials is imminent.The existing organic thermal insulation materials for the wall have the disadvantages of poor fire performance,short aging resistance time and low strength.The inorganic thermal insulation materials represented by vitrified microbeads thermal insulation mortar have better durability and fire resistance,but their thermal conductivity is worse than that of organic thermal insulation materials.Based on this,this paper prepared a new modified vitrified microbead insulation mortar by adding microcapsule phase change paraffin to the existing ordinary vitrified microbead insulation mortar,and focused on the influence of the specific gravity of vitrified microbeads,the amount of vitrified microbeads,the amount of microcapsule phase change paraffin wax and the ratio of water to glue on the physical,mechanical,fire resistance and thermal conductivity of the mortar.Based on the response surface method,the optimal mix ratio of modified vitrified microbead insulation mortar is given.Specific research contents and results are as follows:(1)The influence of the specific gravity and dosage of glass bubbles on the physical,mechanical,thermal conductivity and fire resistance of ordinary glass beads thermal insulation mortar is explored.Through dry density test,compressive strength test,flexural strength test,linear shrinkage test,thermal conductivity test and fire resistance grade test,it is concluded that the dry density,compressive strength,flexural strength and thermal conductivity of thermal insulation mortar prepared by glass bubbles with small specific gravity are relatively small,while the linear shrinkage rate is relatively large.The dry density,compressive strength,flexural strength,linear shrinkage and thermal conductivity of thermal insulation mortar gradually decrease with the increase of glass bubbles amount.The specific gravity and amount of vitrified beads have little effect on the fire resistance.(2)A new type of modified vitrified microbeads thermal insulation mortar was prepared by adding microcapsule phase change paraffin wax into ordinary vitrified microbeads thermal insulation mortar.The influence of the amount of microcapsule phase change paraffin wax on the physical,mechanical,fire resistance and thermal conductivity of modified vitrified microbeads thermal insulation mortar was studied by using single factor method.When the amount of microcapsule phase change paraffin wax is between 0-20%,with the increase of the amount of microcapsule phase change paraffin wax,the dry density and linear shrinkage of modified vitrified microbead thermal insulation mortar first increase and then decrease,the compressive strength and flexural strength first remain unchanged and then increase,the thermal conductivity gradually decreases and the fire resistance gradually deteriorates.(3)Based on the response surface method,the influences of the mixture amount of vitrified microbeads,the mixture amount of microcapsule phase change paraffin and the water-binder ratio on the physical,mechanical and thermal conductivity of the modified vitrified microbeads thermal insulation mortar were studied.The results show that the amount of glass bubbles has the most significant influence on compressive strength,flexographic strength,linear shrinkage and thermal conductivity,and the water-binder ratio has the most significant influence on dry density.The dry density,compressive strength,flexural strength,linear shrinkage and thermal conductivity of modified vitrified microbeads thermal insulation mortar gradually decrease with the increase of the mixture amount of vitrified microbeads and water-binder ratio.With the increase of microcapsule phase change paraffin amount,the dry density,compressive strength and flexural strength of modified vitrified microbeads thermal insulation mortar gradually increased,the linear shrinkage first increased and then decreased,and the thermal conductivity gradually decreased.Considering the performance requirements and economy of various insulation mortar,the optimum mix ratio of modified vitrified microbeads insulation mortar is given as follows: The amount of glass beads is 44%,the amount of microcapsule phase change paraffin is 4%,the amount of cement is 49.3%,the amount of cellulose ether is0.3%,the amount of basalt fiber is 0.6%,the amount of dispersible emulsion powder is 1.2%,and the amount of hydrophobic agent is 0.6%.In view of the poor thermal insulation performance of ordinary vitrified microbeads thermal insulation mortar,a new type of microcapsule phase change material with latent thermal properties was added to the thermal insulation mortar to prepare modified vitrified microbeads thermal insulation mortar.Then,the physical,mechanical,fire resistance and thermal conductivity properties of the modified vitrified microbead thermal insulation mortar were studied,and the main factors affecting the properties of mortar were analyzed by response surface method.Finally,the optimum mix ratio of modified vitrification microbead insulation mortar is recommended,which provides reference for engineering practice.