摘要
混凝土损伤层性能劣化规律对研究硫酸盐侵蚀作用下混凝土耐久性具有重要意义。采用超声波平测法,研究了硫酸盐与干湿交替作用下不同水胶比混凝土的损伤层厚度变化规律,从损伤层角度分析了混凝土的损伤劣化特点与性能退化规律,并采用X衍射方法对混凝土中的主要侵蚀产物进行分析。研究结果表明:随着水胶比增大,混凝土中钙矾石和石膏不断增多,氢氧化钙含量逐步减小,宏观表现为混凝土损伤层中超声波速逐渐减小,损伤层厚度增大。当混凝土损伤层越厚、声速越低时,表明其密实度降低,损伤劣化程度增大。通过测量混凝土损伤层厚度,可以有效判断硫酸盐侵蚀作用下混凝土损伤劣化情况。
For concrete under sulfate attack,the degradation rule of damage layer is very important for studying the durability of concrete. A one-side non-destructive testing method was used to detect the damage layer of concrete with different water-binder ratio subjected to drying-wetting cycles in sulfate solution. The damage degradation characteristic and the performance deterioration of concrete were analyzed by the view of the damage layer. Furthermore,the X-ray diffraction was used to investigate the corrosion products of concrete. The experimental results show that the quantity of ettringite and gypsum in concrete was seen to increase and the corresponding amount of calcium hydroxide decreases steadily with an increase of the water-binder ratio. In the macroscopic aspect,the ultrasonic velocity in the damage layer decreases and the damage layer thickness of concrete increases. When the damage layer thickness of concrete is thicker and the ultrasonic speed is lower,indicating that the compactness of concrete reduces and the deterioration degree of concrete increases. By measuring the damage layer thickness of concrete,the deterioration degree of concrete could be estimated effectively.
出处
《硅酸盐通报》
CAS
CSCD
北大核心
2015年第12期3462-3467,共6页
Bulletin of the Chinese Ceramic Society
基金
教育部创新团队发展计划(IRT13089)
关键词
混凝土
干湿交替
硫酸盐侵蚀
损伤层厚度
concrete
drying-wetting cycle
sulfate attack
damage layer thickness
