大尺寸大开间页岩陶粒混凝土双向叠合板足尺试验研究

针对目前装配式建筑中常用的钢筋混凝土叠合楼板自重较大、工厂标准化生产的预制底板规格尺寸较小的问题,提出了一种由两块预制普通混凝土大板通过一条整体式接缝拼装,并后浇轻质页岩陶粒混凝土而成的大开间叠合楼板,页岩陶粒混凝土后浇层可有效减小楼板自重,提高楼板的保温、隔热和隔声性能。通过进行叠合板足尺试件的堆载试验,研究其在竖向荷载作用下的承载力、变形特征、破坏形态及整体式接缝的传力性能。结果表明,该大开间叠合板试件在正常使用极限状态下的跨中挠度和裂缝宽度均满足相关规范要求,且表现出明显的双向板裂缝分布特征,所采用的整体式接缝具有良好的传力性能,可以作为结构楼板使用。此外,有限元模型所选取的材料本构模型和接触面设定较为合理,计算结果与试验结果吻合良好,可用于轻质混凝土叠合楼板受力性能及影响参数分析。

Full-scale experimental study on large-size and large-span shale ceramsite concrete two-way composite slab

In order to solve the problems of large self-weight of reinforced concrete composite floor slabs commonly used in prefabricated buildings and the small size of the prefabricated bottom plate produced by the factory standardization, a kind of large-span composite floor slab consisted of two prefabricated ordinary concrete slabs assembled through an integral joint and post-poured lightweight shale ceramsite concrete was proposed. The post-pouring layer of shale ceramsite concrete can effectively reduce the self-weight of the floor slab and improve thermal insulation, heat insulation and sound insulation performance of the floor slab. The field surcharge test of full-scale composite slab specimen was carried out to study the bearing capacity, deformation characteristics, failure modes and the force transmission performance of integral joint under the action of vertical loads. The results show that mid-span deflection and crack width of the large-span composite slab specimen under serviceability limit state meet the requirements of the relative codes, crack distribution obviously in accordance with the characteristic of two-way slab. The integral joints used have good transmission performance and can be used as structural floor slabs. In addition, the material constitutive model and laminated surface setting selected by the finite element model are more reasonable, and the simulation results are in good agreement with the experimental results, the model can be used to analyze the mechanical performance and parameters analysis of lightweight concrete composite slabs.