摘要
碳化作用是地下混凝土结构耐久性的重要影响因素之一,由此造成的结构的劣化程度可以用结构保护层碳化的深度表示。该文设计了室内快速碳化试验,建立了混凝土在不同应力水平和不同水灰比及不同碳化龄期情形下的碳化深度模型公式,并得出结论:混凝土碳化速度系数随时间逐渐减小;拉应力对混凝土碳化有促进作用,而压应力则对碳化起到抑制作用;一定范围内,水灰比越大,则碳化速度越快。通过对耐久性评判准则的假设和建立相应的耐久性极限状态方程,可以很好地分析和预测结构的劣化程度及耐久性寿命。
Carbonation is one of the important influence factors on underground concrete structures＇ durability. The deterioration of concrete structures by carbonation can be expressed by the carbonation depth of the protection layer. Indoor fast carbonation experiment was designed and the model of carbonation depth is set up in this paper, which considers diverse stress levels, different water-cement ratio and various operation periods. The model shows： concrete＇s carbonation rate decreases with time slowly; tension stress can accelerate carbonation rate of concrete while compression stress can restrict it; in a certain range, carbonation rate of concrete increases with water-cement ratio. A durability judgment rule is proposed and the corresponding limit condition equation is established for the prediction of the service life of concrete structures.
出处
《工程力学》
EI
CSCD
北大核心
2008年第7期172-178,共7页
Engineering Mechanics
关键词
碳化
应力水平
劣化度
混凝土结构
耐久性寿命
carbonation
stress level
deterioration grade
concrete structures
service life
