Research On Hysteretic And Crack Resistance Of Steel Frame-ALC Wallboard Structure System

Autoclaved Aerated Concrete(ALC)slab is widely used in prefabricated buildings in China because of its advantages of light weight,heat preservation,sound insulation and convenient construction.However,its impact on structural stiffness,energy consumption coefficient and other seismic performance still needs to be further studied in order to make better use of wallboard performance and ensure structural safety.At the same time,in the process of construction and normal use,cracks often appear at the intersection of ALC wallboard and steel beam,steel column,wallboard and wallboard,which affect the waterproof,weather resistance and use effect of the wall,especially under horizontal loads such as wind and earthquake.However,there is a lack of relevant research on the occurrence and development law of cracks in steel frame ALC wall.Therefore,based on the relevant research results of domestic and foreign scholars,the hysteretic performance and crack resistance of ALC wallboard are studied as follows:(1)In order to study the performance of ALC wallboard,three full-scale singlelayer hinged steel frame ALC wallboard specimens were tested by low cycle reciprocating test.The ALC wallboard used pipe clip connector,right angle rigid connector and Ushaped clip connector,and four kinds of finishing methods were set on the wall surface.The results show that: the greater the stiffness of the joint,the higher the stiffness and energy dissipation capacity of ALC wallboard,reflecting better hysteretic performance,and the more serious the failure of the joint.In the early stage of loading,the cracks of decorative surface mainly appear around the joints between ALC board and frame.With the increase of horizontal displacement,the cracks develop continuously.The cracks of pipe clamp and U-clamp specimens appear only when they are close to the elastic-plastic interlaminar displacement angle.The elastic putty joint has not cracked after loading,which indicates that this method is beneficial to the crack resistance of wall panel joint;(2)In order to study the performance of ALC wallboard frame system,three fullscale double-layer single span rigid steel frames embedded with ALC wallboard were tested by low cycle reciprocating test.The ALC wallboard was equipped with built-in anchor connector,hook bolt connector and sliding bolt connector,and eight finishing methods were set on the wall surface.The results show that the lateral bearing capacity and stiffness of the rigid steel frame embedded with ALC wallboard system are 100% and90% higher than those of the empty frame;The stiffness of sliding bolt is 24.4% and 16.2%higher than that of built-in anchor and hook bolt,respectively;The results show that there is no cracking on the surface of the board joint in the method of elastic putty,common caulking mortar and caulking paste,but only cracking on the surface of the board joint in the method of single component sealant,which indicates that the single component sealant is not conducive to the cracking resistance of the surface;The crack resistance of wall panel frame gap is significantly better than that of ordinary caulking mortar;(3)The finite element simulation analysis of rigid steel frame embedded / external ALC wallboard system is carried out.The width,thickness,span height ratio and axial compression ratio of wallboard are selected as parameter variables to analyze their influence on the stiffness and energy dissipation coefficient of the system.The results show that the influence of external ALC wallboard on the lateral performance of the system is negligible,the axial compression ratio increases from 0 to 0.6,and the bearing capacity decreases by 9.9%;With the increase of the thickness,width,span height ratio and axial compression ratio,the stiffness and energy dissipation coefficient of the system increase,and the width has a great influence on the performance of the embedded wallboard system.The stiffness and energy dissipation coefficient of the embedded wallboard system increase by 40.2% and 70% respectively from 300 mm to 700 mm.