In order to overcome the deficiencies of the traditional detection methods, exposure experiment station was established and experimental research on the long-term static or dynamic elastic modulus of bridge concrete in seaward environment was carried out. By using of ultrasonic single side method, longitudinal or surface wave velocity of bridge concrete was obtained through regression calculation of correlative points of the received wave crests about the different ranges. Dynamic elastic modulus of concrete was calculated according to the mathematical relationship with wave velocity. Based on experimental results of a group of pebble concrete specimens, the rule of dynamic elastic modulus of concrete with time was analyzed and the conversion formula between static elastic modulus and dynamic elastic modulus of concrete specimens with pebbles of particle size at 5-20 mm and 5-30 mm was set up. The applicability of the conversion formula was verified by experimental research on the long-term elastic modulus of prestressed concrete members. The results show that dynamic elastic modulus of concrete gradually increases with time. It increases faster in the early period and gradually slowly afterwards. The growth rate gradually decreases with time.%为克服传统测试方法的不足,建立临海环境暴露试验站,开展临海环境下桥梁混凝土长期静、动弹性模量试验研究.运用超声波平测法,取不同测距的接收波波峰相关散点进行回归计算,获取桥梁混凝土的纵波波速与表面波波速,根据动弹性模量与波速的数学关系,计算混凝土的动弹性模量.基于一批卵石混凝土试件的试验结果,分析混凝土动弹性模量随时间变化规律,构建5~20 mm和5~30 mm这2种连续级配粒径卵石混凝土试件的静、动弹性模量换算公式.结合预应力混凝土构件的长期弹性模量试验研究,验证所提出的静、动弹性模量换算公式的适用性.研究结果表明:混凝土的动弹性模量随时间逐渐增大,前期增长迅速,后期增长缓慢,增长速率随时间逐渐减缓.
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