混凝土防冻剂释放氨及尿素含量现场测试方法研究

On-site test of ammonia and urea content released by anti-freezing admixture of concrete

分别采用试验室蒸馏滴定法和现场快速测试方法(纳氏试剂法)对10种不同混凝土防冻剂中所含氨含量进行检测。比较每种防冻剂的检测结果发现,现场快速测试方法测得防冻剂中氨含量与试验室蒸馏滴定法所得结果相近,并且同一防冻剂其两次不同的测量结果波动性较小,说明现场快速检测法可以快速、准确并且稳定的测定防冻剂中释放氨的含量,对于现场的施工过程中氨的预防具有重要意义,同时发现试验室蒸馏滴定法测定不出混凝土防冻剂中的人为添加的尿素含量,而现场快速测试方法(二氯异氰脲酸钠-麝香草酚法)能检测出混凝土防冻剂尿素含量。

It investigated ammonia content in ten kinds of anti-freezing admixture of concrete by means of （laboratory distillation titra-tion method and on-site test：Nessler reagent method）.The result shows that the ammonia content tested by on-site test are uniform with the data tested by laboratory distillation titration method with little fluctuation which meant the on-site test played an important role in ammo-nia-resistance in site operation. Meanwhile,urea content added exteriorly in anti-freezing admixture of concrete could not be tested by lab-oratory distillation titration method while the on-site test（dichloroisocyanuric acid salts-thymol crystals method）could do it.