硅酸盐学报2017，Vol.45Issue(2)：254-259,6.DOI:10.14062/j.issn.0454-5648.2017.02.12
长期荷载作用对粉煤灰混凝土抗碳化性能的影响
Effect of Long-term Loading on Carbonation Resistance of Fly Ash Concrete
摘要
Abstract
In order to analyze the effect of long-term loading on the carbonation resistance of fly ash concrete, the carbonation regularity of concrete specimens with the size of 40 mm×40 mm×160 mm at a concentration (volume fraction) of CO2 (20±3)%, a relative humidity of (70±5)% and a temperature of (20±2)℃ was investigated. After 28-d curing, the concrete specimens were loaded for 3 years (i.e., at compressive stress level of 33%), placed for 3 years without loading and uninstalled after loading for 3 years at the relative humidity of (60±5)% and the temperature of (20±2)℃, respectively. The water-binder ratio is 0.37, 0.45 and 0.53, and the content of fly ash substituting for the equal quality of cement by mass is 0, 30% and 60%, respectively. The mechanism of long-term loading effect on the carbonation resistance of fly ash concrete was analyzed by the sound velocity measurement. The result shows that the long-term loading can reduce the rate of concrete carbonation. The ultrasonic sound speed of specimens after loaded for 3 years is increased by an average of 0.8%, compared to the specimens unloaded, indicating that the internal structure is denser. The average increment value of carbonation depth of fly ash concrete in each group is decreased by 19.2%, compared to the specimens unloaded. The ultrasonic sound speed of specimens uninstalled after loading for 3 years is decreased by an average of 1.1%, compared to the specimens unloaded. The micro-damage in internal of concrete accelerates its carbonation rate. The average increment value of carbonation depth of fly ash concrete in each group is increased by 14.5%, compared to the specimens unloaded. The ultrasonic testing results can indicate the influence of long-term loading on the carbonation resistance of fly ash concrete.关键词
粉煤灰混凝土/长龄期/荷载/碳化Key words
fly ash concrete/long-term/load/carbonation分类
建筑与水利引用本文复制引用
赵庆新,何小军,张津瑞..长期荷载作用对粉煤灰混凝土抗碳化性能的影响[J].硅酸盐学报,2017,45(2):254-259,6.基金项目
国家自然科学基金(51578477)；河北省研究生创新资助项目(00302-6370018)。 （51578477）
