论文部分内容阅读
为评估腐蚀对住宅钢结构性能的影响,首先分别对有涂装和无涂装的Q235B钢材进行了最长达6 400 h的室内盐雾加速腐蚀试验,造成的钢材腐蚀深度等于按已有文献记录的上海大气腐蚀速率计算50 a左右的腐蚀程度,并对这些钢材进行了力学性能试验;然后,分别对有涂装和无涂装的两组焊接H形钢梁进行了最长达2 400 h的室内盐雾加速腐蚀试验,造成的钢材腐蚀深度等于按已有文献记录的上海大气腐蚀速率计算20 a左右的腐蚀程度,并对这两组焊接H形钢梁进行了静力承载力试验;采用最小二乘法回归,分别给出了受腐蚀钢材的屈服强度、抗拉强度和伸长率下降与其失重率的关系式。研究表明:有涂装的H形钢梁腐蚀了2 400 h之后的承载力下降明显,对应挠度值增加明显;比较板厚和单位长度表面积2个几何参数,发现板厚是影响H形钢梁受腐蚀后受力性能的重要因素,翼缘或腹板厚度越小,承载力下降越多、对应挠度值增加越多。
In order to evaluate the effect of corrosion on the properties of residential steel structure, the corrosion accelerated test of salt spray for up to 6 400 h for coated and uncoated Q235B steel was carried out respectively, resulting in the corrosion depth of steel equivalent to that of the existing literature Recorded the corrosion rate of atmospheric corrosion in Shanghai for about 50 years, and tested the mechanical properties of these steels. Then, two sets of welded H-shaped steel beams with and without coating were respectively subjected to a maximum of 2,400 h indoor salt spray accelerated corrosion test, resulting in the depth of corrosion of steel equal to the existing documented atmospheric corrosion rate of Shanghai about 20 a degree of corrosion, and these two groups of welded H-beam static load test The regression equation of least square method was used to calculate the relationship between the yield strength, tensile strength and elongation of the corroded steel and its weight loss rate respectively. The results show that the load-bearing capacity of coated H-beams decreases obviously after 2 400 h corrosion, and the corresponding deflection value increases obviously. Comparing two geometrical parameters of plate thickness and unit surface area, it is found that the thickness of H- Affected by the corrosion of an important factor in the performance of the flange or web thickness is smaller, the more the decline in bearing capacity, the corresponding increase in the deflection value.