不同腐蚀环境作用下玄武岩增强复材筋疲劳性能试验研究

EXPERIMENTAL RESEARCH ON FATIGUE BEHAVIOR OF BFRP BARS UNDER DIFFERENT CORROSION CONDITIONS

酸及高温腐蚀作用下玄武岩增强复材(BFRP)筋疲劳性能的变化规律是研究BFRP筋混凝土结构在复杂环境下疲劳损伤的基础,通过轴向拉伸疲劳试验,观察BFRP筋在不同腐蚀时间及不同温度作用下的外观变化形态和在疲劳荷载作用下的破坏模式,获得各工况下BFRP筋的强度-寿命(S-N)曲线,分析疲劳寿命随腐蚀时间及温度而变化的规律。结果表明:BFRP筋疲劳寿命随温度提高而大幅减小,270℃时,各应力作用下疲劳寿命损失率分别高达80.16%、83.66%、85.03%、87.60%、89.0%;腐蚀时间对BFRP筋疲劳寿命影响显著,应力Smin为415 MPa时,室温条件下,未经酸碱腐蚀的复材腐蚀时间15,30,45 d的复材疲劳寿命损失率分别为26.36%、66.22%、82.68%;应力Smax为795 MPa时,疲劳寿命损失率为67.02%、80.94%、90.55%。

The change law for the fatigue behavior of Basalt Fiber Reinforced Polymer（BFRP） bars under the action of acid and high temperature corrosion is the basis for studying the fatigue damage of BFRP reinforced concrete structure in complex environment.Through the axial tension fatigue test,the appearance changes of BFRP bars with different temperatures and corrosion time were observed,as well as the failure modes under fatigue load,so as to obtain the S-N curves under various conditions to analyze the change law of fatigue life along with corrosion time and temperature.The results showed that the fatigue life of BFRP bars decreased sharply with the increase of temperature.At 270 ℃,the fatigue life loss rates under stress were as high as 80.16%,83.66%,85.03%,87.60%,89.0%,respectively; corrosion time had significant effect on the fatigue life of BFRP bars,when the minimum stress was 415 MPa and the corrosion time of uncorroded bars at room temperature were 15,30,45 d,and the fatigue life loss rates were 26.36%,66.22% and 82.68% respectively; when the maximum stress was 795 MPa,the fatigue life loss rates were 67.02%,80.94% and 90.55% respectively.