基于粗糙集的盐冻作用下混凝土材料耐久性评价指标分析

Analysis of evaluation index of concrete salt freezing based on rough set theory

为探明盐冻作用下混凝土材料各耐久性评价指标的重要程度,通过室内加速试验测定混凝土试件的损伤层厚度、超声波波速、质量损失率、相对动弹性模量、抗压强度5个耐久性评价指标,应用粗糙集条件信息熵理论,建立硫酸盐侵蚀与冻融循环复合作用下混凝土材料耐久性评价指标的权重关系数据模型,分析各指标在混凝土材料耐久性评价中的重要程度.研究结果表明,损伤层厚度(0.30)与超声波波速(0.30)权重最大,质量损失率(0.21)次之,相对动弹性模量(0.19)最小,表明损伤层厚度及超声波波速能更好地反映盐冻作用下混凝土材料的耐久性能,与混凝土试验损伤结果相符;并通过各评价指标相关性提取对应决策规则,为盐冻作用下混凝土材料耐久性评价指标的客观选取提供了重要依据,提高了混凝土冻融侵蚀损伤程度的预测精度。

In order to investigate the importance of frost and salt under the action of concrete materials the durability evaluation index,five durability evaluation index,such as concrete specimen damage layer thickness,ultrasonic velocity,mass loss rate,relative dynamic elastic modulus and compressive strength,was determined through the indoor accelerated test,rough sets conditional information entropy theory was used to bulid the weighted relation data model for evaluating durability of concrete materials under the sulfate corrosion and freeze-thaw cycles.The results show that the damage layer(0.30)and ultrasonic velocity(0.30)are maximum weight,next mass loss rate(0.21 times),the relative dynamic elastic modulus(0.19)is minimum,that reflecting the salt damage thickness and ultrasonic wave velocity can be better freeze-thaw durability of concrete materials under the action and the damage of concrete test results consistent;and corresponding decision rules through the correlation of each evaluation index,providing an important basis for the selection of salt freezing objective evaluation index of durability of concrete under the action of improving the concrete freeze-thaw erosion damage prediction accuracy.