NaCl-MgCl_(2)复合除冰盐对混凝土盐冻破坏的影响及其作用机理

Effect and Mechanism of NaCl-MgCl_(2) Compounded Deicing Salt on the Salt-Frost Scaling of Concrete

研究了NaCl-MgCl_(2)复合除冰盐对盐溶液结冰压和临界饱水度,以及对混凝土盐冻剥蚀破坏和饱水度等的影响,揭示了其降低混凝土盐冻剥蚀破坏的作用机理.结果表明:在NaCl除冰盐中掺入MgCl_(2)可有效降低盐溶液造成的混凝土盐冻剥蚀破坏;随着复合除冰盐中MgCl_(2)掺量的增大,其对盐溶液结冰压的影响很小,但可明显增大盐溶液的临界饱水度;在冻融循环条件下,掺有复合除冰盐的混凝土的饱水度及其增长速率明显降低.

Effects of NaCl-MgCl_(2) compounded deicing salt on the ice-formation pressure and the critical saturation degree of salt solutions, and on the salt-frost scaling and the degree of saturation of concrete were investigated. The mechanism of reducing the salt-frost scaling of concrete by the above compounded deicing salt was revealed. The results show that adding MgCl_(2) into NaCl deicing salt effectively reduces the salt-frost scaling of concrete caused by salt solutions. With the increase of MgCl_(2) content in the compounded deicing salt, the ice-formation pressure of salt solution is less effected, but the critical saturation degree of salt solution is significantly increased, and the degree of saturation of concrete adding compounded deicing salt and its increasing rate is significantly reduced during freezing-thawing cycles.