硫酸盐半浸泡侵蚀下水泥基材料中腐蚀产物的试验研究

Corrosion products of cementious materials under sulfate partial soaking attack

对浓度为5%(质量比)硫酸钠溶液半浸泡不同时期的砂浆试件外观形貌进行了观察,并采用电镜(SEM)、能谱(EDS)和X衍射(XRD)等微观测试方法对砂浆不同侵蚀区域的腐蚀产物进行了测试。结果表明:硫酸钠溶液半浸泡侵蚀条件下,砂浆试件可以分为全浸泡区、潮湿区、结晶区和干燥区。全浸泡区和潮湿区主要以化学腐蚀为主,腐蚀产物主要是钙矾石和石膏。结晶区发生了物理结晶型侵蚀,侵蚀产物有硫酸钠晶体。相同侵蚀时间内,结晶区劣化较全浸泡和潮湿区严重。

The surface morphology of cement mortar under 5% sulfate solution （mass fraction ） partial soaking condition in different ages were observered, and the corrosion products in different attacked areas were testes by scanning electron microscope （SEM）, energy dispersive spectroscopy（EDS ） and x-ray diffraction （XRD） technology, respectively.Results showed that under partial soaking condition, cement mortar were distinguished four zones-soaking zone, wet zone, crystallization zone and dry zone.Corrosion products in soaking zone and wet zone were predominantly ettringite and gypsum,showing chemical corrosion take place in those zones.Crystals of Na2SO4 and Na2SO4·10H20 were found in crystallization area, showing physical crystallization attack occur in this zone.However, there was no any corrosion product founded in dry zone.ln same attacked period, the deterioration of crystallization area was more serious than soaking zone and wet zone.