水泥砂浆表层硫酸盐物质渗透和反应产物的分析  

Analysis of sulfate substance penetration into the surface area of hardened cement mortar and its reaction products

作　　者：王学兵[1] 潘志华[1] 张俊[1] 陈阳义 

机构地区：[1]南京工业大学材料科学与工程学院,江苏南京210009

出　　处：《混凝土》2014年第5期64-67,共4页Concrete

基　　金：国家973项目资助(2011CB013801)

摘　　要：环境介质中的硫酸盐物质向水泥混凝土材料内部的渗透对于其耐久性的研究具有重要意义。采用精密分层取样方法结合化学成分分析和X射线衍射分析方法对浸泡于硫酸盐溶液中的水泥砂浆试样表层SO3含量的分布以及反应产物进行了仔细研究。结果表明：对于硫酸盐溶液中浸泡180d的水泥砂浆试块SO42-渗透深度大约3～5mm；Na2SO。溶液浓度越高，SO3渗透量越多，意味着腐蚀加剧；硫酸盐物质渗入后形成的反应产物主要有钙矾石和石膏，反应产物种类与硫酸盐溶液种类关系密切，5％Na：SO3溶液浸泡主要产物为钙矾石，5％MgSO。或5％（NH4）2SO4溶液浸泡同时形成钙矾石和石膏；超细矿渣粉掺量较少时似乎增加了SO42-的渗透，而较多掺量时对SO42-的渗透似乎能起到扼制作用。The penetration of sulfate substances into hardened cement concrete takes a very large effect on its durability.Therefore, the distribution of SO3 within the surface area of the hardened cement mortar specimen and its reaction products after immersion in different sulfate solution was analyzed in detail by means of chemical composition analysis based on accurate layered sampling and X ray diffraction analysis.Results showed that the penetration depth of the SO42- anions into the surface area of the immersed cement mortar specimens in sulfate solution for 180 days is about 3 to 5 mm,and,the higher the concentration of the sodium sulfate solution the more the SO3 penetrated, implying the intensification of sulfate attack.Ettringite and gypsum are two mostly detected substances as the reaction products of the penetrated sulfates, which vary and largely depend on the kinds of sulfate solution, ettringite being detected when it is immersed in 5%Na2SO4 solution while ettringite and gypsum being detected simultaneously if it is immersed in 5% MgSO4 or 5%（NH4）2SO4 solution. The introduction of ultrafine blast-furnace slag powder into cement mortar in small amount seems to be accelerative to the sulfate penetra- tion while its larger addition proved to be effective for the prevention of the sulfate penetration.

关 键 词：硫酸盐 矿渣粉 渗透 石膏 钙矾石 

分 类 号：TU528.01[建筑科学—建筑技术科学]