帽型薄壁钢梁-轻骨料混凝土组合楼板受力性能试验研究

Experimental study on mechanical property of composite slabs of cap type thin-walled steel beams and lightweight aggregate concrete

由帽型冷弯薄壁钢梁作为组合楼板的承重骨架,与轻骨料混凝土预制板块经后浇水泥砂浆而形成轻质组合楼板。为研究其受力性能,设计并制作了5块具有不同构造特征的组合楼板试件,对其进行了简支条件下的静载试验。结果表明:该组合楼板具有较大的整体刚度和承载能力,当等效均布荷载达到正常使用状态的荷载标准值3.2 kN/m^2时,跨中挠度远小于L/500。当组合楼板的整体变形较大时,帽型钢梁内部的外伸腹板对提高组合楼板的整体刚度产生明显作用,极限状态下割线刚度是帽型钢梁内部无外伸腹板时的2.5倍;当次梁截面高度由20 mm增至50 mm时,组合板的极限荷载增幅为87.5%。

The lightweight composite floors consisting of a set of cap type thin-walled steel beams as load-bearing skeleton and prefabricated lightweight aggregate concrete plates are presented,which is assembled by post-pouring cement mortar. In order to study the mechanical properties of the composite floors,five composite slab specimens were designed and made,and static loading tests were finished. It is shown that the composite floor specimens have better overall stiffness and bearing capacity. The deflection of mid-span of the specimens is much less than L /500 as for the equivalent uniform load is 3. 2 kN/m2 which is the standard value in normal service condition. The effect of the construction of the extension web for the cap-type steel beam on increasing the whole stiffness of the composite slabs is evident for larger deformation of the composite slabs. The secant stiffness of the composite slab with the extension web for the cap-type steel beam at the limit state is 2. 5 times of that of the composite slab without the extension web. When the height of the secondary beam increases from 20mm to 50mm,the ultimate load of the composite plate increases by 87. 5%.