碱渣用作砂浆保水剂的试验研究

An Experimental Study on Applying Soda Residue to Water Retention of Mortar

碱渣是氨碱法制纯碱排出的废渣,其堆存和排放造成严重的环境问题。通过对原状碱渣采取工艺处理得到较低氯离子含量的水洗碱渣和除氯碱渣,研究了原状碱渣、水洗碱渣、除氯碱渣应用于砂浆时对其性能的影响及除氯碱渣用作砂浆保水剂的可行性。结果表明,各类碱渣取代15%粉煤灰均有利于提高砂浆的保水性,但原状碱渣及水洗一次碱渣掺入砂浆后氯离子溶出含量偏高,可能造成耐久性问题;而除氯碱渣不会有耐久性问题,可以作为砂浆保水剂。除氯碱渣用作砂浆保水剂使用时,砂浆具有良好的保水性能、力学性能和较低的干缩值。其较佳的应用方式为:碱渣取代胶凝材料中的部分粉煤灰,在不改变水胶比的前提下,加入减水剂来调节砂浆稠度,无需复合有机保水剂。

Soda residue is the waste discharged from the production of soda ash by ammonia method,its storage and discharge had caused serious environmental problems.The washed soda residue and dechlorination soda residue with lower chloride ion content were obtained by the process of removing chloride ion from the original soda residue.The influence of original soda residue,washed soda residue and dechlorination soda residue on the properties of mortar,and the feasibility of the dechlorination soda residue used as mortar water retention agent were studied.The results show that all types of soda residue replacing 15% of fly ash are conducive to improve the water retention of mortar,but the original soda residue and washed once soda residue may cause durability problems because the higher chloride ion dissolution content.The dechlorination soda residue will not cause durability problems and can be used as mortar water retention agent.When the dechlorination soda residue was used as water retention agent,the mortar had excellent water retention and mechanical properties,and lower shrinkage values.The preferred application way of dechlorination soda residue is replacing parts of the fly ash in the binder,keeping the water binder ratio constant and adding water reducing agent to adjust consistency,and organic water retention agent is not needed.