硫酸盐侵蚀下硬化水泥浆体中硫元素分布规律的微观测试研究  

Microscopic testing of sulfur distribution in hardened cement paste subjected to external sulfate attack

作　　者：李华[1] 孙伟[1] 左晓宝[1,2] 

机构地区：[1]东南大学材料科学与工程学院江苏省土木工程材料重点实验室,江苏南京211189 [2]南京理工大学土木工程系,江苏南京210094

出　　处：《混凝土》2012年第2期4-7,10,共5页Concrete

基　　金：国家重点基础研究发展计划(973计划)(2009CB623203);国家自然科学基金(51078186);江苏省自然科学基金(BK2010071)

摘　　要：利用SEM的BSE成像模式和EDS的Line(线扫描)模式测试了2.5%和5.0%硫酸钠溶液中侵蚀1年的水泥净浆试样中硫、钙、硅元素的分布趋势,定量描述与分析了试样中硫元素的分布规律及其产生的主要原因。结果表明:两种浓度硫酸钠溶液侵蚀下的试样,其表层浆体中硫元素含量较低,近表层区出现"高硫含量"带,"高硫含量"带以内,硫元素含量随试样深度的增加,开始下降明显,后缓慢下降,最终趋于稳定;但5.0%硫酸钠溶液中试样"高硫含量"带的宽度和硫元素含量峰值明显大于2.5%硫酸钠溶液中的试样。为进一步研究水泥基材料中硫酸根离子的传输规律及硫酸盐侵蚀下水泥基材料的损伤劣化机理提供了基础。Backscattered electron image and line scan mode in EDS were adopted to test sulfur, calcium, silicon distribution in cement pastes eroded by 2.5% and 5.0% sodium sulfate solutions for one year,the distribution rules of sulfur were quantitatively described,and the causes producing the distribution are analyzed.The results show that, for specimen in each solution, the sulfur content in the surface paste is low, while in the near-surface zone appears ＂high sulfur content＂ band, after which with the increase of depth, sulfur content firstly decreases significantly, then decreases gradually, finally tends to a constant.Moreover, the width and peak concentration of ＂high sulfur content＂ band of specimen immersed in 5.0% sodium sulfate solution are greater than those in 2.5% sodium sulfate solution.The results obtained provide the basis for the further study on the transporation of sulfate ions in eehmnt-based materials and the deterioration of cement-based materials under sulfate attack.

关 键 词：硫酸盐侵蚀 硬化水泥浆体 硫元素分布 SEM 线扫描 定量 

分 类 号：TU528.01[建筑科学—建筑技术科学]