腐蚀性场地形成的水泥土的劣化研究

水泥土等加固体的劣化可以分为场地环境变化引起已有加固体的劣化问题和在腐蚀性场地形成的加固体的劣化问题。前一个问题是加固体形成一段时间后因外界环境变化而受到侵蚀的问题；后者是加固体在腐蚀性环境中产生强度的同时发生劣化的问题。为了研究加固体在腐蚀性场地的劣化问题，开发了一种能够近似模拟加固体形成环境的养护装置。在试样筒中制备加固体后立即将加固体连同试样筒置于养护筒，并只允许加固体顶面与腐蚀性环境接触，达到一定龄期后实施微型贯入试验及化学成分分析试验，初步研究了海水及其压力对滨海沉积软土场地形成的水泥土劣化的影响。结果表明：海水环境下水泥土的劣化进展较快；劣化深度有随水压力增大的趋势；劣化的发生与 Ca ²⁺ 的溶出有关， Ca ²⁺ 浓度随水泥土深度的变化趋势呈现一定的规律性。

Deterioration of soil cement stabilized in corrosive site

The cement stabilized soil in natural condition,as well as stabilization in corrosive site,will be influenced by environmental pollution such as acid rain,seawater invasion or industrial pollution,which will lead to deterioration of the structure.Especially in the corrosive site,the strength of soil stabilized by cement will increase,but at the same time,it will decrease due to the deterioration at the beginning of stabilization.The experimental work is performed to study the strength of soil stabilized by cement in the corrosive site which is represented by sea water.Laboratory tests are carried out to measure the strength distribution by means of the micro cone penetration tests.Also,the element analysis tests using the ion chromatography to measure the distribution of Ca2+ within the specimen are conducted.The effect of seawater pressure on the strength of cement stabilized marine clay is analyzed.Two conditions are prepared.In the first condition,two meters of seawater pressure are applied to the specimen by using vertical pipe filled by seawater,and the other specimen has no pressure applied.It is indicated that the deterioration extends quickly under seawater environment and the deteriorated depth becomes deeper with the increase of pressure.The element analysis shows that the concentration of calcium ions in deteriorated portion is lower than that in non deteriorated portion.