公路隧道钢筋混凝土衬砌碳化耐久性区划

为了构建公路隧道衬砌碳化耐久性的定量设计方法，对比各碳化深度计算模型与实测数据，选定衬砌碳化的最优模型；根据实测数据分析隧道环境温湿度与洞外大气关系，基于全国气象监测站的温湿度数据，建立公路隧道运营环境温湿度区划；考虑公路隧道CO₂的释放源项并参照实测数据，构建隧道运营环境CO₂体积分数的计算方法；以碳化劣化速率梯度相等为原则，对我国隧道碳化环境进行分区，结合分区推荐我国公路隧道衬砌碳化耐久性定量设计的具体方法. 研究发现：隧道环境湿度与大气湿度相当，隧道环境温度变化趋势与大气环境一致，两者均值接近. 公路隧道内部CO₂体积分数与CO体积分数呈线性关系. 云南、贵州区修建的隧道工程衬砌受环境影响较大，西藏、青海、内蒙古、黑龙江、吉林等地区的待建隧道在进行衬砌耐久性设计时可以忽略碳化影响，其余全国大面积区域隧道衬砌的碳化耐久性设计可以对应《混凝土结构耐久性设计标准》中环境作用等级中的“轻度”进行设计.

Carbonation resistance zonation of reinforced concrete lining of road tunnels

The optimistic model was decided by comparing results from carbonation depth calculation models and tested data, in order to establish a quantitative method for the carbonization durability design of highway tunnel lining. The relationship of temperature and humidity between the tunnel operation environment and the atmosphere was analyzed based on the field test data. The temperature and humidity zonation of road tunnels in China was established based on the temperature and humidity data from meteorological stations. The calculation method of CO₂ volume fraction in the tunnel operation environment was recommended by referring to the emission source of CO₂ as well as the field test data. The carbonation durability of road tunnels in China was divided based on the principle of equalized carbonation degradation rate gradient. Also, the specific method of quantitative design of carbonation durability of road tunnel lining in China was recommended based on the results of the zonation. Results show that the environmental humidity of the tunnel is equivalent to the atmospheric humidity. The temperature trend of the tunnel environment is consistent with that of the atmospheric environment, and the average values of the two are close. The CO₂ volume fraction in the road tunnel is linearly related to the CO volume fraction. The lining of tunnels built in the Yunnan and Guizhou are greatly affected by the environment. The impact of carbonation can be ignored for tunnels in Tibet, Qinghai, Inner Mongolia, Heilongjiang and Jilin. The carbonation durability design of the tunnel lining in other areas of the country can refer to the design of the classification “lightness” in “Standard for design of concrete structure durability”.