盐渍土环境混凝土抗盐离子侵蚀试验研究

盐渍土环境中地基基础混凝土将受到盐离子的侵蚀,影响混凝土的力学特性。通过一系列混凝土侵蚀性试验,研究了普通混凝土和大掺量磨细矿渣耐腐蚀混凝土在氯离子和氯离子硫酸根离子共同作用下抗氯离子侵蚀性能;得到了在饱水条件、不同干湿循环次数下氯离子侵入混凝土深度与浓度的关系;分析了不同水胶比混凝土在氯离子侵蚀下混凝土块强度弱化特性。结果表明:在普通混凝土添加磨细矿渣掺合物可以提高混凝土的抗氯离子能力,相比于饱水条件,干湿循环更容易导致混凝土侵蚀破坏,单一硫酸镁溶液对混凝土的强度弱化将出现初期强度提高的现象,而混合溶液中氯离子抑制了这种现象,混凝土强度在整个过程均降低。

Experimental study on salt ion corrosion of concrete in saline soil environments

The foundation concrete will be eroded by salt ion in saline soil,and the concentration of chloride ion influences the characteristics mechanics of concrete.A series of concrete erosion tests are carried out for sodium chloride solution,magnesium sulfate solution and the mixture solution of sodium chloride and magnesium sulfate.The resistance erosion characteristic of general concrete and corrosion resistant concrete with large amount of ground granulated blast furnace slag are researched.The relationships of corrosion depth and concentration for chloride ion are obtained in conditions of water saturated situation or different drying-wetting cycles times.And the strength degradation characteristics of concrete samples with different water cement ratio are analyzed under chloride erosion.The test results indicate that,the large amount of ground granulated blast furnace slag concrete can improve the resistance to chloride ion.Compared with water saturated situation,drying-wetting cycles conditions are more likely to cause erosion and failure for concrete.The initial strength degradation will increase when the concrete sample in magnesium sulfate solution.But in the mixture solution of sodium chloride and magnesium sulfate,the phenomenon of strength increasing will be controlled by chloride ion,and the strength of concrete decreases during the whole erosion process.