现浇圆形管空心楼盖中单向模型板受力性能的试验研究

Experimental study on mechanical properties of one-way model slab from cast-in-situ floor system with one-way cylindrical cavity

本文通过三个对比组的模型试验,对比研究了现浇圆形管空心楼盖中单向横孔模型板与单向顺孔模型板的受力性能和剪力传递特征。研究表明,当空心率在35%以下时,横孔模型板与顺孔模型板受力变形特征几乎完全相同;当空心率达到50%时,横孔模型板仍然具有良好的抗弯刚度,为进一步研究现浇空心楼盖的双向受力特征奠定了基础。同时,研究还发现,横孔板孔肋是剪力传递的薄弱环节,建议应对其进行抗剪验算。此外,本文还对现浇圆形管空心楼盖抗弯纵筋的最小配筋率的取值提出了修正建议。

Based on the experimental results of three couples of contrast specimens from cast-in-situ cylindrical hollow slab, the mechanical properties and shear transfer mechanism of one-way transverse hollow slab strip and longitudinal hollow slab strip have been studied. It is shown that when cavity ratio is lower than 35 %, the mechanical properties of both transverse and longitudinal hollow slabs are almost just the same, and when cavity ratio approaches to 50%, the flexural rigidity of transverse hollow slab still keep close pace with that of longitudinal counterpart, which lays a good foundation for further research of oneway cast-in-situ cylindrical hollow floor system. Also, the experiments show that cavity ribs are the weakest link for shear transfer, and check for their shear resistance has been recommended. In addition, the modified minimum flexural reinforcement ratio is proposed as well.