预制再生块体混凝土板-梁连接的受弯性能研究及其工程应用

Flexural behavior of prefabricated recycled lump concrete slab-beam assembly and its engineering application

为提高装配式混凝土结构中预制板、梁的现场施工效率,提出了带外伸齿条的预制板。开展了4个预制装配再生块体混凝土板-梁试件和2个整浇再生块体混凝土板-梁试件的受弯试验,考察了制作方式、板厚及外伸齿条数量对板-梁连接负弯矩区受弯行为的影响,并在某办公楼建筑中对该板-梁连接技术进行了试点应用。试验结果及工程实践表明:预制装配板-梁试件的最大裂缝出现位置与整浇板-梁试件不同;预制装配板-梁试件的极限荷载要高于整浇板-梁试件,但板端外伸齿条数量对极限荷载影响很小;相比于整浇板-梁试件,板厚增加对预制装配板-梁试件极限荷载的提高幅度偏小;与传统预制板、梁的现场拼装相比,带外伸齿条的预制板与预制梁拼装时无需板下临时支撑,可提高施工效率,节省施工成本。

To improve the construction efficiency of precast slabs and beams in prefabricated concrete structures,the precast slab with extruded racks was proposed.Four prefabricated recycled lump concrete slab-beam assemblies and two cast-in-place recycled lump concrete slab-beam assemblies were experimentally studied to investigate the influences of fabrication method,slab thickness,and number of extruded racks on the flexural behavior of the slab-beam assemblies under negative bending moment.The precast slabs with extruded racks were applied in an office building.The test results and engineering practice show that:the position of the maximum crack of the prefabricated slab-beam assembly is different from that of the cast-in-situ slab-beam assembly;the ultimate load of the prefabricated slab-beam assembly is higher than that of the cast-in-place slab-beam assembly,but the number of extruded racks has little effect on the ultimate load;compared with the cast-in-place slab-beam assembly,the increment of the ultimate load of the prefabricated slab-beam assembly,due to the increase of the slab thickness,is relatively small;and in comparison with the in-situ assembly of traditional precast slabs and beams,temporary supports under the slabs are not required when the precast slabs with extruded racks are assembled with the precast beams,leading to significantly higher construction efficiency and less costs.