论文部分内容阅读
为研究直径和腐蚀环境对BFRP筋拉伸力学性能影响,开展了三种直径(6 mm、8 mm、10 mm)BFRP筋试件在自然环境、碱溶液环境(pH=10)、紫外线照射环境(辐照度为550W/m~2)及两种腐蚀环境交叉作用下拉伸试验,采用扫描电子显微镜(SEM)对BFRP筋拉伸断裂进行了分析,并对试验结果进行了研究。主要结论如下:三种不同环境作用下,随着腐蚀时间延长,BFRP筋抗拉强度减小且强度退化率逐渐下降,BFRP筋弹性模量上下波动均不超过5%,且无明显规律,断裂伸长率变化趋势与拉伸强度基本相同;紫外线环境下BFRP筋抗拉强度有退化和不完全恢复现象;交叉环境下直径分别为6 mm和8 mm BFRP筋抗拉强度也有退化和不完全恢复现象,10 mm BFRP筋则没有。基于本文所定义的耐久性衰减速率,对直径分别为6mm和8 mm BFRP筋耐久性的影响,碱环境最大,交叉环境居中,紫外线环境最小;对10 mm BFRP筋耐久性的影响,交叉环境最大,碱环境居中,紫外线环境最小。三种不同环境作用下,直径为6 mm BFRP筋耐久性衰减平均速率均最大,直径为10 mm的测试结果均最小。
In order to study the influence of diameter and corrosive environment on the tensile properties of BFRP bars, three kinds of specimens (6 mm, 8 mm, 10 mm) were tested in natural environment, alkaline solution (pH = 10), UV irradiation (Irradiance of 550W / m ~ 2) and two kinds of corrosive environment. The tensile fracture of BFRP bars was analyzed by scanning electron microscope (SEM), and the experimental results were studied. The main conclusions are as follows: Under the three different environments, with the prolongation of corrosion time, the tensile strength of BFRP tendon decreases and the strength degradation rate gradually decreases. The elastic modulus of BFRP tend to fluctuate up and down not more than 5%, and there is no obvious regularity and fracture The trend of elongation is basically the same as that of tensile strength; the tensile strength of BFRP tendon under ultraviolet light environment is degraded and incompletely restored; the tensile strength of BFRP tendons with 6 mm and 8 mm diameter respectively in crossed environment also degenerated and incompletely restored Phenomenon, 10 mm BFRP tendon did not. Based on the durability decay rate defined in this paper, the durability of BFRP tendons with diameters of 6mm and 8mm, respectively, is the highest, with the highest alkali environment, the middle cross environment and the least UV environment. The durability of 10 mm BFRP tendons is the largest , Alkali environment, the smallest, the UV environment. Under the three different environments, the average attenuation rate of durability of BFRP tendons with the diameter of 6 mm is the largest, and the test results with the diameter of 10 mm are the smallest.