脱硝粉煤灰中残留铵对粉煤灰品质和砂浆性能的影响  

Effect of the Ammonia Present in Fly Ash on the Properties of Fly Ash and Mortar

作　　者：刘艳霞[1] 孔祥芝[1] 吴葵 张思佳[1] 纪国晋[1] 刘晨霞[1] LIU Yanxia;KONG Xiangzhi;WU Kui;ZHANG Sijia;JI Guojin;LIU Chenxia(China Institute of Water Resources and Hydropower Research,Beijing 100048,China)

机构地区：[1]中国水利水电科学研究院,北京100048

出　　处：《水力发电》2022年第2期125-131,共7页Water Power

基　　金：国家重点研发计划(2016YFB0303601),中国长江三峡集团公司科研项目(JG/18032B)。

摘　　要：通过试验研究了粉煤灰残留铵含量(单位质量粉煤灰铵含量分别为10、70、150、250、390 mg)对粉煤灰品质、新拌砂浆性能、砂浆力学性能及硬化砂浆气泡参数的影响。结果表明,铵含量在10~390 mg/kg之间变化对其化学成分、物理性能、微观颗粒形貌和粒度分布基本没有影响;砂浆流动度随着粉煤灰铵含量的增加大致呈增加趋势,凝结时间呈下降趋势;当粉煤灰含量为35%和50%时,胶砂强度随铵含量增加略有下降;随着粉煤灰中铵含量增加,硬化砂浆中的气泡个数、气泡比表面积和含气量呈增加趋势,但气泡平均弦长、平均半径和气泡间距系数总体上呈下降趋势。建议工程在选取粉煤灰时,安排必要的现场试验,科学合理地确定铵含量的安全限值。The effect of ammonia present in fly ash with different ammonia contents(10,70,150,250 mg/kg and 390 mg/kg)on the quality of fly ash,the performance of fresh mortar,the mechanical properties of mortar and the air void parameter of hardened mortar are studied by experiments.It indicated that,(a)the ammonia content between 10-390 mg/kg has basically no effect on the chemical components,physical properties,microscopic particle morphology and particle size distribution;(b)the fluidity of fresh mortar generally increases with the increase of the ammonia content of fly ash,while the setting time shows a downward trend;(c)when the content of fly ash is 35%or 50%,the strength of hardened mortar decreases slightly with the increase of ammonia content;and(d)with the increase of ammonia content in fly ash,the air void number,air void specific area and mortar air contents show an increasing trend,but the average chord length,average radius and spacing coefficient of voids generally show a downward trend.It is proposed that necessary experiments should be carried out when choosing fly ash so as to reasonably determine the safety limit value of ammonia.

关 键 词：粉煤灰 铵含量 水泥砂浆 力学性能 气泡参数 影响 

分 类 号：TU528[建筑科学—建筑技术科学] TV431[水利工程—水工结构工程]