垃圾焚烧炉渣中可溶盐对水泥稳定材料性能的影响

Influence of Soluble Salt in Waste Incineration Bottom Ash on Performance of Cement Stabilized Material

为将生活垃圾焚烧炉渣用于水泥稳定材料的道路基层,分析了生活垃圾焚烧炉渣中氯盐和硫酸盐的含量,通过无侧限抗压强度试验和劈裂强度试验分析了氯盐和硫酸盐对水泥稳定炉渣碎石混合料强度的影响,通过干缩试验和温缩试验分析了氯盐和硫酸盐对混合料变形性能的影响,并采用微观测试方法分析了氯盐和硫酸盐对混合料的微观作用机理。结果表明:试验垃圾焚烧炉渣中可溶氯盐和硫酸盐含量平均值分别为0.57%,1.01%;对掺30%左右垃圾焚烧炉渣的混合料,当垃圾焚烧炉渣中氯盐、硫酸盐含量分别达到1.67%,2.00%后,混合料的强度明显降低,氯盐、硫酸盐含量分别超过0.67%,1.00%后混合料的干缩变形和温缩变形均明显增大;水洗处理可降低垃圾焚烧炉渣中可溶盐含量,掺水洗垃圾焚烧炉渣的混合料的强度没有明显变化,短期干缩变形有所增大,温缩变形降低;微观分析表明,Cl^-与水泥水化产物发生化学反应生成Friedel盐,掺氯盐、硫酸盐的混合料内部水化产物增多,但当掺Na_2SO_4含量达到1.0%时,部分水泥颗粒未水化。为保证水泥稳定炉渣碎石混合料的性能,应限定垃圾焚烧炉渣中可溶盐的含量。

In order to utilize municipal solid waste incineration bottom ash（ IBA） in cement stabilized materials for road base,the contents of soluble salts including chloride salt and sulfate salt in the IBA are tested. The effects of soluble salts on the strength of cement stabilized IBA and crushed stone mixture are analyzed by applying unconfined compressive strength test and splitting strength test. The effects of soluble salts on the deformation property of the mixture are analyzed by applying dry shrink test and temperature shrink test. Besides,the microscopic mechanism of chloride and sulfate salts on the mixture is analyzed by micro test method. The result shows that（ 1） The average contents of chloride and sulfate salts in the tested IBA are 0. 57% and 1. 01% respectively.（ 2） For the mixture contained 30% IBA,the mixture＇s strength is significantly decreased when the content of chloride and sulfate salts in IBA is more than 1. 67% and 2. 00%respectively,and the mixture＇s dry shrinkage deformation and temperature shrinkage deformation are significantly increased when the content of chloride and sulfate salts is more than 0. 67% and 1. 00%respectively.（ 3） Water treatment can reduce the soluble salts content in IBA,the strength property of the mixture contained IBA with water treatment shows no significant difference compared with control mixture,while the short shrinkage deformation increases and the temperature shrinkage deformation decreases.Microscopic analysis shows that Cl--reacts with cement hydration products to produce Friedel salts,and hydration products increased in the mixture with addition of chloride and sulfate salts. However,some cement particles are not hydrated when the Na2 SO4 content is 1. 0%. In order to ensure the performance of the mixture,the content of soluble salts in IBA should be limited.