钢筋混凝土平屋面的楼房两端顶层纵墙斜开裂,多发生在房屋长宽比比较大的砖混结构。这种裂缝均呈正八字形,沿纵墙斜对角,有窗的沿窗口两对角方向裂开,中间大两头小,白天大夜间小,白天呈拉开形,夜间呈挤压形。这种裂缝一经出现,往往很难处理,严重危及房屋使用安全,特别对于纵墙承重体系及纵横墙承重体系影响尤烈。为防 In the reinforced concrete flat roof, the vertical walls of the two top floors of the building are inclined and cracked, which mostly occurs in the brick-concrete structure with a large ratio of length to width of the house. The cracks are of a figure eight, diagonally diagonally along the vertical wall, and are split in two diagonal directions along the window with a window. The middle two are small, small during the day, small during the day, stretched during the day, and extruded at night. Once this type of crack has appeared, it is often difficult to handle, which seriously jeopardizes the safety of the use of the house, especially for the vertical wall bearing system and vertical and horizontal wall bearing system. For prevention