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一、概述析白是建筑物的混凝土、砂浆、砖砌体等表面上经常发生的现象,俗称为泛碱或起霜。析白是由于水泥、砂、石、砖等材料中的可溶性成分被水溶解后,伴随着混凝土、砂浆及砖砌体表面的水分蒸发,在硬化体表面析出或进而与空气中的CO~2等作用生成白色沉积物的结果。这些白色物质的化学成分随使用材料、施工工艺、发生时间、季节及环境等的不同而异,X衍射分析结果,常见的有Ca(OH)_2、CaCO_3、CaSO_4、Na_2SO_4、Na_2CO_3、K_2CO_3等。水泥中的游离CaO与水反应及水泥主
I. Overview Separation of whiteness is a phenomenon that often occurs on the surface of concrete, mortar, brickwork, etc. of buildings, commonly known as ubiquitous or blooming. Whitening is due to the dissolution of soluble components in materials such as cement, sand, stone, bricks, etc., which are dissolved in water and then evaporates on the surface of concrete, mortar, and brickwork, and precipitates on the surface of the hardened body or CO 2 in the air. Efforts are made to produce white deposits. The chemical composition of these white substances differs depending on the materials used, the construction process, the time of occurrence, the season, and the environment. X-ray diffraction analysis results include Ca(OH)2, CaCO3, CaSO4, Na2SO4, Na2CO3, and K2CO3. Free CaO in cement reacts with water and cement