外墙涂层对混凝土耐久性的影响

目的探索外墙涂层提高混凝土耐久性的能力。方法通过室内碳化试验、氯离子侵蚀试验、盐酸侵蚀试验、吸水率试验,系统地研究混凝土表面涂刷外墙涂层对其耐久性的影响。结果碳化60 d,涂刷外墙涂层R的试件碳化深度比空白件下降了53.4%。龄期90 d时,空白件的电通量为2423 C,渗透等级为"中";而涂刷外墙涂层R的试件电通量为1599 C,渗透等级为"低"。4%(质量分数)盐酸溶液腐蚀28 d后,空白件的抗折强度仅为涂刷外墙涂层R的试件的42.7%。浸水4,8,12,24 h后,涂刷外墙涂层R的试件吸水率分别比空白件降低了67.4%,51.7%,41.7%,18.0%。结论混凝土表面涂刷外墙涂层后,抗碳化、抗氯离子和盐酸侵蚀的能力有所改善,吸水率降低,耐久性得以提高。

Impact of Exterior Wall Coating on Concrete Durability

Objective To explore the ability of exterior wall coating to improve the durability of concrete. Methods The influence of painting of concrete surface on the concrete durability was systematically studied through carbonation test, chloride ion erosion test, hydrochloric acid erosion test and water absorption test. Results When the carbonization time was 60d, the carbonation depth of specimen painted by the exterior wall coating R was decreased by 53. 4% , compared with the blank specimen. At the age of 90 days, the electric flux of the blank specimen was 2423 coulomb, and the penetration level was " medium" . While the electric flux of the specimen painted by the exterior wall coating R was 1599 coulomb, and the penetration level was " low" . The flexural strength of blank specimen was only 42. 7% comparing with specimen painted by exterior wall coating R, when immersed in 4% hydrochloric acid for 28 days. After immersed for 4 h, 8 h, 12 h, 24 h, the water absorption of specimen painted by exterior wall coating Rwas reduced by 67. 4% , 51. 7% , 41. 7% and 18. 0% , respectively, compared with the blank specimen. Conclusion Painting the concrete surface by exterior wall coating could improve the ability of concrete carbonation, chloride ion erosion, hydrochloric acid erosion and reduce the water absorption of concrete. Exterior wall coating could improve the durability of concrete.