基于三点弯曲试验的混凝土叠合梁跨中挠度研究

STUDY ON MID-SPAN DEFLECTION OF REINFORCED CONCRETE COMPOSITE BEAM BASEDON THREE-POINT BENDING TEST

预制装配式结构采用工厂预制与现场安装相结合的方式,可降低环境污染,减少资源浪费,其中装配式混凝土结构常采用叠合梁、叠合板,叠合结构整体性和抗震性能好。选取某构件厂成品叠合梁(YKL2a-XS-1)进行了三点弯曲试验,获得叠合梁荷载挠度曲线,分析叠合梁跨中挠度与荷载的关系;依据梁跨中挠度计算公式,计算叠合梁跨中挠度。叠合梁加载变形特点与适筋梁受弯性能相似,加载期间,叠合面无滑移,预制再生混凝土与后浇普通混凝土整体性较好;随着荷载增加,叠合梁的挠度增加,跨中挠度实测值增加幅度最大,跨中挠度未超过设计限值,叠合梁满足工程实际中构件的延性要求;依据梁跨中挠度计算公式得到的跨中挠度理论值高于真实值。

Prefabricated structures are made in plants and installed on site to reduce environmental pollution and resource waste.Common prefabricated concrete structures include composite beams and composite slabs,with high integrity and seismic performance.The three-point bending test was performed to the composite beam(YKL2A-XS-1)from a component factory to obtain the load-deflection curve.In addition,the relationship between the mid-span deflection and load of the composite beam was analyzed.The mid-span deflection of the composite beam was calculated by the corresponding formula.The deformation of the composite beam under load is similar to the flexural behavior of the balanced reinforced beam.In the loading process,the composite surface has high integrity between the precast recycled concrete and post-cast plain concrete,without slipping.As more loads are applied,the deflection of the composite beam increased,and the measured mid-span deflection increased the most but did not exceed the design limit.The composite beam meets the ductility requirements of components in engineering applications.The theoretical mid-span deflection calculated by the formula was greater than the real value.