EVA乳液改性岩棉-砂浆界面及其耐碱侵蚀性研究

Study of rock wool-mortar interface modified by EVA emulsion and its alkali resistance

使用EVA乳液对岩棉-砂浆界面进行改性以增强其结构稳定性,研究了EVA改性岩棉-砂浆界面的防水性能、EVA乳液对岩棉抹面砂浆水化过程的影响、EVA改性岩棉的耐碱侵蚀性。结果表明:EVA乳液在碱性介质中发生水解反应抑制了前期水化硅酸钙(C-S-H)絮状凝胶的生成,延缓水泥的水化进程。后期C_(4)H_(6)CaO_(4)·2H_(2)O随着时间的推移发生分解,导致砂浆中的CaCO_(3)含量增加,有利于阻止外界有害介质侵入破坏岩棉,能够有效提高岩棉与砂浆的粘结性能和整体防水性能。同时EVA乳液失水干燥后在岩棉纤维表面形成一层高分子薄膜,一定程度上提高岩棉纤维的耐碱侵蚀性。

Ethylene/vinyl acetate(EVA)emulsion was used to modify the rock wool-mortar interface to enhance its structural stability.The waterproof performance of EVA modified rock wool-mortar interface,the influence of EVA emulsion on the hydration process of rock wool plaster mortar,and the alkali corrosion resistance of EVA modified rock wool were studied.The results show that the hydrolysis reaction of EVA emulsion in alkaline medium inhibits the formation of calcium silicate hydrate(C-S-H)succulent gel and delays the hydration process of cement.At the later stage,C_(4)H_(6)CaO_(4)·2H_(2)O decomposed with the passage of time,leading to the increase of CaCO_(3) content in the mortar,which is conducive to preventing the intrusion and destruction of rock wool by external harmful media,and the bonding and waterproof performance between rock wool and mortar and the overall can be effectively improved.At the same time,after dehydration and drying,EVA emulsion forms a layer of high molecular film on the rock wool fiber,thus improving the alkali resistance of the rock wool fiber to a certain extent.