不同构造形式绿色混凝土叠合板受弯性能试验

Experiment on Flexural Behavior of Green Concrete Composite Slab with Different Structural Forms

为推动绿色再生类材料在叠合楼板中的应用,将不同性能要求的钢纤维增强绿色混凝土材料应用于叠合板中,研究不同构造形式所组成的钢纤维绿色混凝土叠合板受弯性能差异.开展了6块钢纤维增强绿色混凝土叠合板和2块普通混凝土叠合板足尺试件的抗弯性能对比试验.得到了其破坏形态、荷载-跨中挠度曲线、荷载-跨中板底受力钢筋应变曲线及荷载-跨中板顶面混凝土压应变曲线等特征参数,对比分析了各试件的破坏机理、变形特征、裂缝分布规律.研究结果表明,钢纤维增强绿色混凝土叠合板与普通混凝土叠合板相比受弯破坏过程类似,均经历了弹性阶段、弹塑性阶段及破坏阶段,且裂缝、挠度发展均较为充分,未有突然断裂或沿叠合面出现水平裂缝等破坏现象,均具有较好的延性;同时,不同的预制底板构造形式对叠合楼板的受弯性能也有较大影响,其中配置钢筋桁架的叠合板,尤其是附肋钢筋桁架对叠合板的受力性能有较为显著的提高;开裂荷载及极限承载力计算应考虑构造形式及不同混凝土材料预制底板对所组成叠合板受弯性能的影响.

Steel fiber reinforced green concrete was applied to the composite slab in order to promote the application of green ecological materials in the composite slab. The flexural behavior of the steel fiber reinforced green concrete composite slab with different structural forms were studied. Full-scale comparative test of six steel fiber reinforced green concrete composite slabs and two ordinary concrete composite slabs were carried out. The characteristic parameters, such as failure mode, load-deflection curves, load-rebar strain curves, and load-concrete strain curves, were obtained. Further, the failure mechanism, deformation characteristics, and crack distribution were comparatively analyzed. The results show that the flexural processes of eight specimens are similar, which experienced elastic stage, elastic-plastic stage and failure stage. All specimens are bonded well on the connection interface,with out any break-off and other phenomenon but with good cooperative work performance. Meanwhile, different structure forms of prefabricated base slabs have significant influence on the flexural behavior of the composite slab. It is noted that steel bar truss with ribs improves the flexural behavior of the composite slab significantly. In addition, the cracking strength and ultimate load-carrying capacity of the composite slab were affected by the effects of different structural forms and different material on flexural behaviour of prefabricated base slab.