碱渣用作矿物掺合料对混凝土性能影响的试验研究

Experimental study on the performance of concrete using soda residue as mineral admixture

碱渣是氨碱法制纯碱排出的废渣,由于含有大量的可溶性氯离子,碱渣直接用作混凝土掺合料时,会导致钢筋锈蚀,从而大大降低建筑物的使用寿命。为解决碱渣应用的难题,对原状碱渣采用工艺处理得到不同氯离子含量的水洗碱渣和除氯碱渣,研究了三种碱渣对混凝土性能的影响。结果表明,碱渣掺入会严重降低混凝土的工作性能,但可以通过增加减水剂掺量的方式调节;在碱渣掺量为10%时,用碱渣等量取代粉煤灰或水泥时混凝土强度均略有增大;较高氯离子含量的原状碱渣和水洗碱渣均会造成钢筋锈蚀,只有氯离子含量低于0.30%的除氯碱渣可作为混凝土矿物掺合料使用,且无需掺加阻锈剂。

Soda residue is the waste of ammonia soda process producing the soda ash.Because it contains a large amount of soluble chloride ions, it can cause steel corrosion when directly applied to concrete as admixture, thus greatly reducing the life of the building.To solve the problem of soda residue applications, through the process for original soda residue, get the washing soda residue and dechlorination soda residue with low chloride content,and study the effect of the three kinds of residue on concrete performance.The results show that the incorporation of soda residue would seriously reduce the performance of concrete, but can be adjusted by adding superplasticizer.When the content of soda residue is 10% to replace the same amount of fly ash or cement, the concrete strength both will increase slightly.The original soda residue and washing soda residue with high chloride ion content will cause steel corrosion, only the dechlorination soda residue which chloride content of less than 0.30% can be used as mineral admixtures, without adding rust inhibitor.