摘要
双掺细粉料掺加到预应力混凝土在桥梁的应用较为广泛,但对其力学性能存在一些疑虑。基于相似理论,制作缩尺比例1∶5的模型梁,混凝土强度等级为C50,以5 Hz频率的半正弦波恒定应力加载,进行200万次疲劳加载循环,分析不同掺量双掺细粉料模型梁的弯曲疲劳性能。结果表明,在200万次疲劳加载后模型梁没有疲劳裂缝,疲劳性能稳定,疲劳试验后破坏试验强度没有明显的降低,疲劳后静力受力性能稳定,掺加细粉料对混凝土梁有明显的改善作用。其中,在20万次循环以下,双掺细粉料混凝土梁的应变迅速增加,弯曲刚度迅速减小;超过20万次循环后,应变增加的速度和弯曲刚度减小的速度显著减慢。综合分析表明,所有双掺细粉料混凝土梁都表现出良好的弯曲疲劳性能,值得在工程中推广。
Double-mixed fine powder admixture to prestressed concrete is more widely used in bridges,but there are some doubts about its mechanical properties.Based on the similarity theory,a scaled-down model girder of 1∶5 was made,and the concrete strength grade was C50,loaded with a half-sine wave constant stress at a frequency of 5 Hz,and 2 million fatigue loading cycles were carried out,to analyze the bending fatigue performance of the model girder with different dosages double-doped fine powder.The results show that there is no fatigue crack in the model beam after 2 million fatigue loading cycles,the fatigue performance is stable,the destructive test strength does not decrease significantly after the fatigue test,the static stress performance is stable after fatigue,and the doping of fine powder has an obvious improvement effect on the concrete beam.Among them,below 200,000 cycles,the strain of double-doped fine powder concrete beams increased rapidly,and the bending stiffness decreased rapidly.After more than 200,000 cycles,the rate of strain increases,and the rate of bending stiffness reduction slows down significantly.Comprehensive analyses show that all double-mixed fine powder concrete beams exhibit good flexural fatigue performance,which is worth promoting in engineering.
作者
张志国
李浩然
潘冀蒙
郭文涛
苏靖海
ZHANG Zhiguo;LI Haoran;PAN Jimeng;GUO Wentao;SU Jinghai(Shool of Civil Engineering,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;Shanxi Construction Engineering Group Co.,Ltd.,Taiyuan 030000,China;Shijiazhuang City Construction Group Constructional Engineering Testing Service Co.,Ltd.,Shijiazhuang 050000,China)
出处
《粉煤灰综合利用》
2025年第1期119-123,144,共6页
Fly Ash Comprehensive Utilization
基金
河北省交通运输厅重点项目(Y-2010024)。
关键词
高性能混凝土
疲劳性能
等幅疲劳试验
high performance concrete
fatigue performance
constant amplitude fatigue test
