高铵盐粉煤灰在混凝土中的应用研究  

The applied research on the fly ash with high ammonium salt in the concrete

作　　者：刘冠杰[1,2] 陈玉峰 任建国[1,2] 

机构地区：[1]山西大学化学化工学院,山西太原030006 [2]山西山大合盛新材料股份有限公司,山西太原030006 [3]山西恒台建业集团有限公司,山西太原030032

出　　处：《新型建筑材料》2016年第11期27-29,38,共4页New Building Materials

摘　　要：从近期某工程中新拌混凝土浇筑后持续冒泡,并产生刺鼻氨味的异常现象出发,在混凝土的原材料中查找引起该现象的原因。通过实验室分析与现场调查,基本确认了粉煤灰中的铵盐是产生气体的主要来源物质。对粉煤灰中铵盐类物质过量的原因进行了探寻,其主要的原因是在火电厂对烟尘进行的脱硝处理工艺中,使用了大量的液氨或尿素,而逃逸的氨与烟气中的硫氧化物反应生成大量铵盐,从而引起此类物质在粉煤灰中的富集。搅拌站使用此种粉煤灰预拌混凝土时,铵盐会在碱性环境下持续反应放出氨气,在混凝土表面产生泡眼,对混凝土的表观和抗压强度造成不利影响。Starting from the abnormal phenomena that after pouring the fresh concrete,it continued bubbling, and produced the pungent odor of ammonia,this paper aims to find the reasons for this phenomenon in the raw materials of concrete. Through laboratory analysis and field investigation, it is basically eonfirmed ＇that the ammonium salt in the fly ash is a major source material whieh produees odor. Further exploring the cause of the excess ammonium salt in the fly ash, it is found that the main reason is during the DeNOx process of smoke and dust in the eoal-fired power plants,large amounts of liquid ammonia or urea is used,so escape of ammonia and SOx in flue gas react to produce a large amount of ammonium salt,which cause the enrichment of such substances in the fly ash. When this fly ash is used by the stirring stations to premix the concrete,ammonium salt would continue to react in alkaline environment to release ammonia, and produce air bubble in concrete surface,whieh have bad effect on concrete surface appearance and compressive strength.

关 键 词：混凝土气泡 粉煤灰 铵盐 脱硝工艺 

分 类 号：TU526[建筑科学—建筑技术科学] X773[环境科学与工程—环境工程]