Research On The Performance Of Autoclaved Aerated Concrete Self-insulation Wall Used In Cold Regions

With the rapid development of the Chinese economy,construction has become a major source of energy consumption,which is dramatically increasing in recent years.For this reason,energy conservation is considered as a major issue.Improvement of external wall enclosure structure to save energy consumption is important for our society.Autoclaved aerated concrete(AAC)is the only material that can satisfy the requirement of 65% energy saving of buildings in cold regions.Therefore,the self-insulation wall made based on AAC has also received extensive research attention.This article is based on the application of AAC in cold regions.Based on the former results reported in the literature,we explored the mix ratio and the technique for industrial applications regarding AAC,and the insulation masonry used for AAC self-insulation wall.Then,according to the climate conditions of cold regions,numerical simulation method was applied to analyze the temperature distribution,thermal stress and total wall deformation of AAC self-insulation wall.Based on the previously investigated fundamental results,different air-entrainment mode and air-entraining agents were used to explore the optimal performance of AAC.The result showed that a 0.08% dosage of aluminite powder could effectively improve the performance of AAC,and the inclusion of ferrosilicon alloy powder(1/5 of aluminite powder)could properly enhance the pore structure of AAC.Moreover,calcium chloride could be added appropriately to improve early strength of AAC.By regulating the manufacturing technique,a B05 grade AAC with excellent performance can be fabricated.The special thermal insulation mortar for AAC self-insulation wall was tested.The proportion of masonry thermal insulation mortar was determined as cement: fly ash: vitrified microbeads: re-dispersible polymer powder: HPMC: air-entraining agent: water reducing agent = 70:30:60:1:0.8:0.02:0.3;the ratio of plastering thermal insulation mortar was cement: fly ash: vitrified microbeads: fiber: re-dispersible polymer powder: HPMC: water reducing agent: air-entraining agent= 85:15:70:0.6:1.5:0.6:0.3:0.02.The performance of these two special insulation mortars is closer to that of AAC blocks,which can effectively prevent the formation of hot bridges and empty drums.The result indicated that the special thermal insulation mortars are suitable for practical usages.Based on calculation of the thermal performance,an AAC self-insulation wall structure for cold area is developed.By means of numerical analysis,temperature distribution,stress distribution and wall deformation in different seasons were analyzed in ANSYS software.The results showed that the temperature stress and deformation in wall mortar layer are always greater than that in AAC layer;the maximum thermal stress and deformation are within the allowed range of the material,which can effectively avoid the cracking of the wall.