摘要
针对新疆高寒地区桥面板水泥混凝土处于气候严寒和氯盐侵蚀的工作环境,设计桥面板混凝土配合比正交因素表以及混凝土盐冻、水耦合试验方案。通过混凝土盐冻后剥蚀量和动弹性模量损失,分析用水量、水胶比、引气剂掺量以及粉煤灰掺量对桥面板混凝土抗盐冻性能的影响规律。通过混凝土内部结构、力学性能以及耐磨性变化规律分析盐冻对混凝土的性能影响规律。结合性能损伤试验,分析桥面板混凝土抗盐冻性能改善机理,提出基于抗盐冻性能设计的桥面板混凝土配合比建议值。试验结果表明:用水量和引气剂掺量对桥面板混凝土的抗盐冻性能起决定性作用,方差分析值分别为92.80和59.35;用水量由144 kg/m^3增至156 kg/m^3,混凝土相对动弹模量减小了4.85%,剥蚀量由1.68 kg/m^2增至1.93 kg/m^2,增幅约14.8%;引气剂掺量从0.4‰增至1.2‰,混凝土的相对动弹模量增幅达到4.4%;混凝土盐冻剥蚀量与相对动弹模量呈线性关系,随着剥蚀量的增加相对动弹模量逐渐减低;经过300次冻融循环后,混凝土的抗弯拉强度损失率均超过17%,水胶比由0.34增至0.4,混凝土的抗弯拉强度损失率由21%增至33%;3种水胶比时,100次盐冻循环后混凝土的磨损量提高了6%,说明盐冻虽然能加快混凝土表面砂浆层剥蚀速度,但对混凝土剥蚀面以下砂浆层磨损不明显。
Aiming at the severe cold weather and chloride-eroded working environment of bridge deck concrete in alpine area of Xinjiang, the orthogonal factor table of bridge deck concrete mixing ratio and the test scheme of salt-freezing-water coupling on concrete are designed. The influences of water consumption, water-binder ratio, air-entraining agent content and fly ash content on the salt-freeze resistance performance of bridge deck concrete are analyzed by using the denudation and the dynamic elastic modulus loss of concrete after salt freezing. In addition, the influence of salt freezing on the performance of concrete is analyzed through the internal structure, mechanical property and the wear resistance change rule of concrete. Combining with the performance damage test, the salt-freeze resistance performance improvement mechanism of bridge deck concrete is analyzed, and the recommended value of the mixing ratio of bridge deck concrete based on salt-freeze performance design is proposed. The test result shows that(1) the water consumption and the of air-entraining agent content play the decisive role in the salt-freeze resistance performance of bridge deck concrete, and the variance analysis values are 92.80 and 59.35 respectively;(2) as the water consumption increased from 144 kg/m^3 to 156 kg/m^3, the relative dynamic modulus of concrete decreased by 4.85%, the denudation increased from 1.68 kg/m^2 to 1.93 kg/m^2, with the increase of approximately 14.8%;(3) as the air-entraining agent content increased from 0.42‰ to 1.2‰, and the relative dynamic elastic modulus of concrete increased by 4.4%;(4) the amount of salt-freeze denudation of concrete is linearly related to the relative dynamic elastic modulus, and the relative dynamic elastic modulus is gradually reduced as the denudation increases;(5) after 300 freeze-thaw cycles, the flexural strength loss rate of concrete exceeded 17%, the water-binder ratio increased from 0.34 to 0.4, and the bending strength loss rate increased from 21% to 33%;(6) for the 3 wa
作者
郭寅川
申爱琴
郑盼飞
李鹏
GUO Yin-chuan;SHEN Ai-qin;ZHENG Pan-fei;LI Peng(Key Laboratory of Highway Engineering in Special Region of Ministry of Education,Chang'an University,Xi'an Shaanxi 710064,China;Louisiana Transportation Research Center,Louisiana State University,Baton Rouge,Louisiana 70803,USA)
出处
《公路交通科技》
CAS
CSCD
北大核心
2019年第3期73-79,共7页
Journal of Highway and Transportation Research and Development
基金
国家自然科学基金项目(51278059)
关键词
桥梁工程
推荐配合比
正交法
高寒地区
桥面板
抗盐冻性
bridge engineering
recommended mixing ratio
orthogonal method
alpine region
bridge deck
salt-freeze resistance
