为获得合理的临海隧道衬砌混凝土配合比和提高混凝土自防水性能，以拱北隧道工程为背景，开展混凝土在临海侵蚀环境下的自防水性能试验研究。基于系统化的混凝土配合比设计方法确定防水混凝土初步配合比，通过碳化和硫酸盐侵蚀室内试验模拟临海环境对混凝土自防水性能的影响，对混凝土抗压强度、抗水渗透和抗氯离子渗透3个指标进行试验分析，最终获得最优配合比。结果表明： 1）复掺(20%粉煤灰+10%矿渣)混凝土自防水性能最好，该方案可作为拱北隧道主体结构混凝土配合比； 2）在碳化和硫酸盐侵蚀作用下，混凝土的抗氯离子渗透能力随时间逐渐减弱、抗压强度随时间逐渐增强； 3）混凝土掺合料对抗氯离子渗透能力的增强作用非常明显，但对混凝土后期强度增幅有一定的影响。

In order to obtain reasonable mix ratio of coastal tunnel lining concrete and improve selfwaterproof performance of concrete，taking the Gongbei Tunnel project as background, the selfwaterproof performance study of concrete in the coastal erosion environment is carried out. The preliminary mix ratio of the waterproof concrete is determined based on systematic concrete mix ratio design method. The influence of the coastal environment on the selfwaterproofing performance of concrete is simulated by carbonation and sulfate erosion laboratory test. Through the test analysis of concrete compressive strength, water resistance and chloride ion resistance, the optimal mixture ratio is obtained. The result shows that: (1)The concrete with 20% fly ash and 10% slag has the best selfwaterproof performance, which can be used as the main structure of Gongbei Tunnel. (2)Under the carbonation and sulfate erosion, the chloride ion resistance of concrete decreases with time and its compressive strength increases. (3)The strengthening effect of concrete admixtures on chloride ion resistance is very obvious, but it has certain influence on the increase of concrete strength in later period.