既有建筑物底层墙面泛碱成因分析及防治对策

Forming Factors of Crystalline Bloom and Countermeasures on Ground Floor Metope of Current Buildings

河南大学既有建筑物墙面出现了粉化、起鼓或空鼓、开裂、剥落、结晶、墙截面缩小且强度降低等泛碱病害,其成因与地基土类型及化学成分、墙身及饰面材料及其孔隙、表面水、地下水位及水质、大气温度及湿度、光照、通风情况等有关。表面水引起的泛碱病害是局部的,地下水转换为毛细水引起的泛碱病害是主要原因,且具有长期性、循环性的特点。既有方法均治标不治本,无法根除碱害。提出了封堵法、灌浆法及高压旋喷灌浆法的防治对策。

The serious crystalline bloom phenomenon appears on the metope and surface decoration of ground floor of the first and second western old style house of Henan University, such as surface decoration＇s powdering, knobbing and hollowing, fracturing, coming off, riming etc. Its forming factors are related with kinds and chemic element of foundation soils, materials and porosity of walls and surface decoration, surface water, groundwater hydrograph and quality, atmospheric temperature and humidity, light treatments and ventilation situation. The reasons are strongly connected with surface water and groundwater, especially with the transform from groundwater to capillary water in the wall. Its breakage is long-term and has a characteristic of periodicity and circulation. The methods to solve crystalline bloom completely based on others＇ treatments and experiences of water conservancy project are put forward. It is proved effective by application of water conservancy project.