预应力带肋叠合板力学性能试验研究

Experimental Research on Mechanical Properties of Prestressed Ribbed Composite Slabs

提出一种新型预制预应力带肋叠合板(简称预应力叠合板),适用于民用建筑装配式混凝土结构的楼板,为得到该预应力底板和预应力叠合板的荷载-挠度曲线、裂纹发展规律及破坏特征等力学性能,并为实际工程运用提供依据,采用均布加载方式进行试验研究。试验结果表明,预应力底板加载至施工荷载时,4.5m板跨预应力底板跨中挠度为20.50mm,满足施工要求,6.4m板跨预应力底板跨中挠度为72.13mm,需增设支撑;在正常使用荷载下,预应力叠合板跨中挠度小于规范限值,板底未开裂;在极限荷载作用下,新旧混凝土交界面结合良好,未出现裂缝、滑移等剪切破坏现象,预应力钢丝未发生滑移和脆断,有较大的安全储备。

This paper presents a new type of prefabricated prestressed ribbed composite slabs(prestressed composite slabs),which is suitable for the floor of prefabricated concrete structure of civil buildings.In order to obtain the mechanical properties such as load deflection curve,crack development law and failure characteristics of prestressed bottom slabs and prestressed composite slabs,they are tested experimentally by uniform loading in this paper,which provide a basis for the use of actual engineering.Tests show that when the prestressed bottom slabs is loaded to the construction load,the deflection of the prestressed bottom slabs of the 4.5 m span is 20.50 mm,which meets the construction requirements,while the 6.4 m span is 72.13 mm,which additional support is required.Under normal use load,the deflection of the prestressed composite slabs is less than the specification limit,the bottom of the slab is not cracked,and the interface between the new and old concrete is well connected.Under the limit load,no shear failure phenomena such as cracks and slippage occurres,and the prestressed steel wire does not slip and become brittle,prestressed ribbed composite slabs have a large safety reserve.