不同老化处理方式对混凝土防腐蚀涂层表面状态和拉伸性能的影响

Influence of different aging treatment methods on concrete corrosion-resistant coating and tensile performance

选择醇酸、丙烯酸、聚氨酯和氟碳4类涂料进行对比试验,研究其耐紫外、耐湿热和耐碱溶液的性能。试验结果表明:醇酸涂层和丙烯酸涂层整体耐老化性能较差,湿热老化处理7 d后,试件的失光率高达90%以上,表面出现严重的开裂和起泡现象。聚氨酯涂层耐碱溶液的性能较好,但是受紫外老化和湿热老化影响较大,其紫外老化28 d后失光率大于75%,拉伸强度和断裂伸长率下降超过40%,湿热老化7 d后的失光率达97%,表面开裂和起泡情况严重。氟碳涂层耐老化性能优异,老化28 d后失光率不到20%,表面无粉化、开裂、起泡、剥落等现象,拉伸性能未受损害。4类涂层耐老化性能的顺序为醇酸涂层<丙烯酸涂层<聚氨酯涂层<氟碳涂层。

The paper carries out comparative studies on the resistance performance of four coating materials-alcohol acid,acrylic acid,polyurethane and fluorocarbon-against UV,moisture-heat and aqueous alkali.The results indicate that the first two choices-being alcohol acid and acrylic acid-deliver a poor aging performance,as both display a more than 90%gloss loss with severe cracking and foaming after seven days of moisture-heat treatment.Polyurethane on the other hand performs well in terms of aqueous alkali resistance,yet the coating is heavily influenced by UV and moisture-heat.The paper noticed（in the polyurethane specimen） an above 75%gloss loss and a more than 40%drop in tensile strength and in extensibility after 28 d of UV treatment.And 7 d moisture-heat treatment gives rise to a 97%gloss loss and severe cracking and foaming.As for the fluorocarbon,it stands out for its aging resistance,as28 d aging treatment only results in a less than 20%gloss loss.At the same time,no visible pulverization,cracking,foaming or exfoliation is noticed and the tensile performance is hardly undermined.Therefore it can be concluded that the ranking list for the above mentioned four specimens should be alcohol acid acrylic acid polyurethane fluorocarbon.