江西省大中型混凝土水库大坝溶出性侵蚀调查研究

混凝土水库大坝的溶出性腐蚀严重影响大坝的稳定和安全。采取实地考查取样、测定分析相结合的方法,对江西省内35座混凝土水库大坝的溶出性腐蚀情况进行了系统分析。研究结果表明,江西省内大中型水库大坝遭受不同程度的溶出性侵蚀,低HCO₃^-浓度的环境水是导致混凝土腐蚀的重要因素。在环境水HCO₃^-浓度低时,混凝土及填缝灌浆水泥基材料的组成、配合比、施工质量及养护时间对防止大坝的溶出性腐蚀起关键作用。近年来进行过除险加固的部分水库大坝仍存在较严重的溶出性腐蚀,亟需对混凝土中钙离子的迁移动力、微观溶出机理及抑制溶出腐蚀的途径等溶出性腐蚀问题进行深入系统的研究。

Investigation on Dissoluble Erosion of Large-and-Medium-Sized Concrete Dams in Jiangxi Province

The dissoluble erosion of concrete affects the stability and safety of dams seriously.In this research,concrete's dissoluble erosion of 35 dams in Jiangxi province was analyzed systematically by means of field survey,water and precipitate sampling and analyzing.Results show that the large and medium-sized dams in Jiangxi Province suffered from erosion of different levels,and the ambient water with low concentration of HCO32-is an important factor which leads to the corrosion of concrete.When dams are exposed to water of low HCO32-concentration,the composition,mix proportion,construction quality and curing time of concrete play critical roles in preventing the dam from dissoluble erosion.Though the dams have been reinforced in recent years,some of them are still suffering from severe dissoluble erosion.Therefore,in-depth and systematical researches are necessary on the dynamic migration of Ca2+,the microcosmic mechanism of dissolution and the way of inhibiting the erosion.