| Building facing layer is a comprehensive structural system including building external thermal insulation system and building external facing.It has good thermal insulation capacity and decorative effect.At present,it has been widely used in the reconstruction projects of new residential buildings and old residential areas.However,under the influence of many factors such as temperature,humidity,load,material property degradation and service life,different degrees of cracking,hollowing and spalling will occur in the use of building facing layer,which will cause different degrees of casualties and economic losses.It is necessary to study the safety performance of building facing layer under the condition of temperature load coupling.Firstly,the pull-out test of anchor bolt used in building facing layer is carried out,and the pull-out bearing capacity of anchor bolt under different working conditions is obtained by taking the anchorage mode and anchorage depth(50mm,60 mm,70mm,80mm)as control variables.The refined model of bearing capacity is established by ABAQUS finite element software.The deviation between simulation and test data is4.82%,which is in good agreement with the test results.The results show that the anchoring force of the anchor bolt for external wall insulation is related to the anchoring depth of the anchor bolt.Under the same conditions,the anchoring force of the anchor bolt increases with the increase of the anchoring depth.Secondly,according to the classification of architectural facing layer,it is divided into rigid facing layer,semi-rigid facing layer and flexible facing layer.Based on the bolt pull-out test data and modeling data fitting results,the structural system of facing layer is modeled and analyzed,and the damage evolution process and failure mechanism of facing layer are obtained.The results show that: the thermal insulationeffect of the building facing layer is remarkable,and the anchor bolt for external wall insulation has thermal bridge effect in the facing layer.Under the same surface load,the temperature has significant influence on the Mises principal stress and normal bonding stress of the facing layer,and the stress of the facing layer under the temperature load coupling is higher than that under the single load.Low temperature has a significant impact on the building facing layer,and the building facing layer is more prone to cracking,hollowing,spalling and other damage in the low temperature environment in winter.Finally,in view of the lack of scientific methods for the safety evaluation of the facing layer,this paper analyzes the influencing factors of the facing layer based on the appearance and structure detection index,material performance detection index and bearing capacity detection index,determines the weight and membership relationship of the relevant influencing factors,and establishes a more systematic evaluation index system of the facing layer,so as to effectively evaluate the facing layer Systematic evaluation.Combined with the structural characteristics of perforated brick,hollow brick and other hollow masonry walls,the anchoring method of mechanical bite force as the main force and friction force as the auxiliary force is adopted,and the technical scheme of new anchor bolt is put forward. |
