摘要
在对某隧道衬砌混凝土进行微细观结构参数和自然碳化深度测定的基础上,提出了考虑隧道内部高浓度二氧化碳影响的衬砌混凝土自然碳化速度数值预测方法。采用所提出的基于微细观结构参数的自然碳化模型对所研究的公路隧道衬砌混凝土自然碳化进程进行了预测分析,并将衬砌混凝土服役1年自然碳化深度数值计算结果 0.4 mm和预制现场取样的管片混凝土自然碳化试验结果 1 mm进行对比分析。结果表明,两者还是相对比较符合的,因此可以判定所提出低水胶比混凝土自然碳化速度预测模型可以用于对同类型公路隧道衬砌混凝土自然碳化性能进行预测分析。预测分析结果表明,在考虑服役隧道高浓度二氧化碳影响的条件下,该低水胶比公路隧道衬砌混凝土的自然碳化速度相对较慢,其10年自然碳化深度仅为1.5 mm,15年自然碳化深度进展不明显,而其在服役100年时的自然碳化深度小于15 mm。因此,该自然碳化速度数值预测方法可以为预测评估高浓度二氧化碳条件下隧道低水胶比衬砌混凝土的抗碳化性能提供了技术支持。
Based on the testing results of micro-meso structural parameters and natural carbonation depth of lining concrete for a tunnel,a numerical prediction method on natural carbonation speed of tunnel lining concrete considering the high concentration of CO2 inside the tunnel is proposed. By using the proposed natural carbonation model based on micro-meso structural parameters,the natural carbonation process of the researched highway tunnel lining concrete is predicted and analyzed,and the calculated natural carbonation depth 0. 4 mm of lining concrete in 1 year service and the corresponding natural carbonation test result of segment concrete sample at precast site are compared and analyzed. The result shows that numerical result of the model is significantly lower than the test result,but if considering the drilling test error itself and the difference of service environment,they are relatively consistent. Thus it is determined that the proposed natural carbonation speed prediction model with lower water-cement ratio can be used to predict the same natural carbonation performance of the same type of tunnel lining concrete. The simulation and analysis result shows that considering the influence of high concentration of CO2 inside vehicle in-service tunnel,the natural carbonation rate of lining concrete with lower water-cement ratio of highway tunnel is slower,the predicted10-years natural carbonation depth is only 1. 5 mm,and the development of 15-year natural carbonation depth is not obvious,while the 100-years natural carbonation depth is less than 15 mm. Therefore,the proposed natural carbonation ratio numerical method can be adopted to provide a technical support for the prediction and evaluation of the anti-carbonation property of lining concrete with low water-cement ratio in tunnel under high concentration of CO2.
作者
巴明芳
薛涛
黄国阳
李永强
BA Ming-fang;XUE Tao;HUANG Guo-yang;LI Yong-qiang(School of Architectural,Civil Engineering and Environment,Ningbo University,Ningbo Zhejiang 315211,China)
出处
《公路交通科技》
CAS
CSCD
北大核心
2018年第9期56-62,共7页
Journal of Highway and Transportation Research and Development
基金
国家自然科学基金项目(51478227
51778302)
浙江省自然科学基金项目(LY17E080009)
宁波市自然科学基金项目(2017A610311)
关键词
隧道工程
碳化耐久性
数值计算
衬砌混凝土
低水胶比
tunnel engineering
carbonation durability
numerical simulation
lining concrete
low water-cement ratio
