施工期钢筋混凝土受弯构件承载性能研究

研究施工期钢筋混凝土受弯构件的受力特征并建立承载力计算模型,为分析施工期钢筋混凝土结构的承载性能提供可靠的理论依据,对钢筋混凝土结构施工期的安全性分析与控制以及钢筋混凝土结构全寿命分析具有重要的理论意义和实际价值。选取14,180 d两个混凝土龄期,对4根钢筋混凝土梁进行承载力试验,观测试件的破坏形态及变形特点,对比两个龄期极限弯矩值的大小,分析跨中挠度、跨中混凝土应变分布、钢筋自由端滑移等变量随荷载的变化规律。通过对施工期钢筋混凝土受弯构件的数值模拟,分析施工期钢筋混凝土受弯构件主要的受力特征。运用极限平衡理论,建立施工期钢筋混凝土受弯构件正截面承载力的计算模型,分析施工期钢筋混凝土受弯构件承载力随龄期而变化的规律。

STUDY ON BEARING CAPACITY OF REINFORCED CONCRETE FLEXURAL MEMBER DURING CONSTRUCTION

Studying the bearing capaicty characteristics of in-built concrete flexural members and establishing the capacity calculation method,can provide a reliable theoretical basis to the analysis of the bearing capacity of in-built reinforced concrete structure,and has important theoretical significance and value of engineering application for the security analysis and control of reinforced concrete construction and the process life cycle analysis of reinforced concrete structures.Two concrete ages of 14,180 d were selected,the bearing capacity of four reinforced concrete beams were tested,failure modes of specimens and deformation characteristics were observed,the difference of ultimate moment was compared,the change laws of some variables such as deflection,strain distribution across the concrete,free end slip of reinforcement were analyzed.Through numerical simulation,the main force characteristics of in-built reinforced concrete flexural members were analyzed.Combining with the limit equilibrium theory,the capacity calculation model of in-built RC flexural member was established,the bearing capacity time-varying law of reinforced concrete flexural strength during construction was analyzed.