粉煤灰中残留氨含量对混凝土性能影响
|
摘要
分析了粉煤灰中残留氨的存在形态,初步确定残留氨的存在形态为物理吸附的氨气、硫酸铵和硫酸氢铵。通过外掺硫酸铵的方法,研究粉煤灰中残留氨含量对混凝土性能的影响,研究结果表明:当粉煤灰中硫酸铵含量在2 000 mg/kg范围内,粉煤灰掺量为35%时,随着硫酸铵含量的增加,混凝土初始含气量略微增大,抗冻性能和抗渗性能略微降低,混凝土的初始坍落度和1 h变化率、1 h含气量变化率、凝结时间、抗压强度和劈拉强度不受硫酸铵含量变化的影响。
The existing form of residual ammonia in fly ash is analyzed and initially determined as ammonia,ammonium sulfate and ammonium hydrogen sulfate. The effects of residual ammonia content in fly ash on concrete performance are studied by the method of ammonium sulfate addition. The research results show that,when the content of ammonium sulfate in fly ash is not more than 2 000 mg/kg and the dosage of fly ash is 35%,the initial gas content of concrete increases slightly and the frost resistance and impermeability decrease slightly with the increases of ammonium sulfate content,and the initial slump,1 h change rate of slump,1 h gas content change rate,setting time,compressive strength and tensile strength are not affected by the change of ammonium sulfate content.
The existing form of residual ammonia in fly ash is analyzed and initially determined as ammonia,ammonium sulfate and ammonium hydrogen sulfate. The effects of residual ammonia content in fly ash on concrete performance are studied by the method of ammonium sulfate addition. The research results show that,when the content of ammonium sulfate in fly ash is not more than 2 000 mg/kg and the dosage of fly ash is 35%,the initial gas content of concrete increases slightly and the frost resistance and impermeability decrease slightly with the increases of ammonium sulfate content,and the initial slump,1 h change rate of slump,1 h gas content change rate,setting time,compressive strength and tensile strength are not affected by the change of ammonium sulfate content.
引文
[1]BITTNER J,GASIOROWSKI S,HRACH F.Removing ammonia from fly ash[C]∥International Ash Utilization Symposium,2001.
[2]张宇,王智,孙化强,等.脱硝后粉煤灰中氨氮物质的性质探讨[J].粉煤灰,2015(5):5-6.
[3]张宇,王智,王子仪,等.燃煤电厂脱硝工艺对其粉煤灰性质的影响[J].非金属矿,2015,38(4):9-12.
[4]黄洪财.粉煤灰氨味问题成因的调查研究[J].新型建筑材料,2013(12):23-25.
[5]黄晓天.混凝土氨释放问题的研究[J].中国西部科技,2015,14(8):68-70.
[6]张晓利.问题粉煤灰引起的混凝土冒泡的原因分析[J].江西建材,2015(14):6.
[7]罗斌.新拌混凝土的氨昧分析及对强度的影响[J].湖南交通科技,2015,41(3):33-36.
[2]张宇,王智,孙化强,等.脱硝后粉煤灰中氨氮物质的性质探讨[J].粉煤灰,2015(5):5-6.
[3]张宇,王智,王子仪,等.燃煤电厂脱硝工艺对其粉煤灰性质的影响[J].非金属矿,2015,38(4):9-12.
[4]黄洪财.粉煤灰氨味问题成因的调查研究[J].新型建筑材料,2013(12):23-25.
[5]黄晓天.混凝土氨释放问题的研究[J].中国西部科技,2015,14(8):68-70.
[6]张晓利.问题粉煤灰引起的混凝土冒泡的原因分析[J].江西建材,2015(14):6.
[7]罗斌.新拌混凝土的氨昧分析及对强度的影响[J].湖南交通科技,2015,41(3):33-36.