混凝土结构早龄期应力相关应变现场监测与分析  

IN SITU MONITORING AND ANALYSIS FOR STRESS-DEPENDENT STRAINS OF EARLY AGE CONCRETE STRUCTURES

作　　者：王国杰[1] 郑建岚[1] 

机构地区：[1]福州大学土木工程学院,福建福州350002

出　　处：《工程力学》2009年第9期61-66,73,共7页Engineering Mechanics

基　　金：国家自然科学基金项目(50478003)

摘　　要：该文研究采用振弦应变计监测混凝土结构早龄期的应力相关应变。由理论分析提出一套自浇注入模起计算混凝土应力相关应变的方法,该方法摒弃了随龄期变化的参数,直接由应变读数计算混凝土应力相关应变,因而适合自混凝土入模起的早龄期混凝土。随后通过某大桥0#段V撑混凝土自入模起至14d龄期的监测实例,验证了混凝土应变计算的全过程;同时结合水化温度信号,对混凝土凝结硬化过程中应变的产生、发展和变化过程进行了分析,阐述了应变测试过程中几个特征点的含义。结果表明:该方法能用于混凝土结构早龄期的应力相关应变监测,并使混凝土结构应力相关应变计算更简便、精确;此外,该方法还有助于揭示混凝土结构早龄期水化、变形、约束等方面的相互关系和应力相关应变的形成机理。Stress-dependent strains monitoring of early-age concrete structures by embedded vibrating wire sensors is investigated. A methodology to calculate stress-dependent strains form the very beginning of concrete placing is developed, which can be done directly by vibrating wire strain readings without the efforts to identify time dependent parameters such as expansion coefficients of early age concrete. Then a concrete V shaped strut of a long span bridge is instrumented and monitored continually for a period of 14 days by vibrating strain and temperature sensors. With the measured strain readings and temperature data, the process of stress-dependent strain calculation is validated and the strain evolution with concrete hardening is analyzed. The results show that the methodology is practicable in early age concrete structures and make stresses calculation more convenient and accurate. It can be used to indicate the strain developing mechanism and to identify the complicated relationships between hydration, deformation, and restraint of early age concrete.

关 键 词：早龄期混凝土 应变测试 振弦式应变计 应力相关应变 温度效应 收缩 开裂 

分 类 号：TU528.01[建筑科学—建筑技术科学]