建筑外墙外保温系统锚栓变幅疲劳性能试验研究

Experimental study on variable amplitude fatigue performance of anchor bolts of external thermal insulation system of building exterior wall

分别对不同基材、不同锚入深度和不同循环荷载下的锚栓进行抗拉试验、常幅疲劳试验和变幅疲劳试验,研究锚栓的抗拉承载力标准值F和疲劳性能。结果表明,锚栓在不同基材上的抗拉承载力标准值由大到小为:C40混凝土、C30混凝土、A5.0砌块、A3.5砌块、A2.0砌块。锚栓的常幅疲劳次数与抗拉承载力标准值不完全成正比,会受到循环荷载与锚入深度的共同影响。A3.5砌体基材上锚栓的常幅疲劳性能最好,当锚入深度为75 mm时最经济。通过锚栓变幅疲劳试验发现,在A3.5砌体基材中,前期0.3F的初始循环荷载对锚栓疲劳性能造成的损伤随初始循环荷载的增加而增大,应力等级损失Di最高可达0.40810。

The tensile test,constant amplitude fatigue test and variable amplitude fatigue test are carried out for anchor bolts under different base materials,different anchoring depth and different cyclic load peaks to study the standard value of tensile bearing capacity and fatigue performance of anchor bolts.The test results show that the standard values of tensile bearing capacity of anchor bolts on different base materials are from large to small:C40 concrete,C30 concrete,A5.0 block,A3.5 block,A2.0 block.However,the number of constant amplitude fatigue of anchor bolt is not completely proportional to the standard value of bearing capacity,and it will be affected by the combination of cyclic load and anchor depth.The constant amplitude fatigue of anchor bolt on A3.5 block masonry substrate is the best,and is the most economical when the anchoring depth is 75 mm.Through the variable amplitude fatigue test of anchor bolt,it is found that in the A3.5 masonry base material,the damage caused by the initial cyclic load of 0.3F in the early stage to the fatigue performance of anchor bolt increases with the increase of the initial cyclic load,and the maximum loss of stress grade can reach 0.40810.