预应力RPC-NC叠合梁挠度试验及计算方法  

Experimentation and calculation methods of prestressed RPC-NC composite beam deflection

作　　者：季文玉[1] 李旺旺[1] 过民龙 王珏 

机构地区：[1]北京交通大学土木建筑工程学院,北京100044

出　　处：《吉林大学学报（工学版）》2018年第1期129-136,共8页Journal of Jilin University:Engineering and Technology Edition

基　　金：国家自然科学基金项目(51278040);教育部中央高校基本科研业务费专项资金项目(2014YJS106)

摘　　要：为提高桥梁结构抵抗变形的能力,提出了预应力活性粉末混凝土(RPC)-普通混凝土(NC)叠合梁结构形式,并设计了10根预应力RPC-NC叠合模型梁和1根NC对照梁。试验研究了预应力度、RPC高度、NC等级等因素影响下叠合梁跨中挠度发展特性及计算方法。结果表明:叠合梁跨中挠度发展可分为开裂前弹性阶段、带裂缝工作阶段、普通钢筋屈服后迅速增长阶段3个阶段。预应力度越高,开裂前弹性段越长,开裂后屈服和强化阶段的刚度下降越快。根据试验值对铁路桥规和混凝土规范中的公式进行修正,修正后的计算结果与试验值吻合良好。To improve the anti-deformation capacity of bridge structure, prestressed Reactive Powder Concrete （RPC）-Normal Concrete （NC） composite beam is proposed and ten prestressed RPC-NC composite beams and one NC beam were designed. Experiments of the mid-span deflections of the composite beams are conducted and the calculation method of the reflection is proposed. The influence of the degree of prestress, height of RPC and concrete degree of NC are considered in the experiments. The results show that the developing process of the deflection of composite beam can be divided into three stages, the elastic stage before cracking, cracking stage, rapid increasing stage after the yield of reinforcement. The higher the degree of prestress is, the longer the elastic stage is before cracking of the mid-span load-deflection, and the faster the stiffness yield and strength phase fall. The formulas of code for design of concrete structure and code for design for design of reinforced and prestressed concrete structure of railway bridge and culvert are modified based on the testing results. The calculated results by the modified formulas are in good agreement with the testing results.

关 键 词：道路工程 活性粉末混凝土 普通混凝土 叠合梁 等效刚度 弯曲挠度 

分 类 号：TU378.2[建筑科学—结构工程]