重金属离子对蒸养混凝土力学性能影响及其浸出特性研究  

Effects of Heavy Metal Ions on Mechanical Properties and Leaching Characteristics of Steam Curing Concrete

作　　者：苏小梅[1] 李坚[2] 

机构地区：[1]武汉城市职业学院,武汉430064 [2]武汉船舶职业技术学院,武汉430050

出　　处：《硅酸盐通报》2018年第2期625-629,共5页Bulletin of the Chinese Ceramic Society

摘　　要：蒸养混凝土具有早期强度高、模具周转速度快和生产效率高等显著优势,成为混凝土预制构件主要制备工艺。通过抗压强度、离子浸出试验、X射线衍射等测试方法,研究了锌、铬、铜对蒸养混凝土的力学性能、水化产物结构及其浸出特性,并探讨了粉煤灰对蒸养混凝土固化重金属离子效果的影响规律。结果表明:(1)Zn、Cr和Cu离子能够在不同程度上降低蒸养混凝土的抗压强度,当掺量为1.0%时,抗压强度分别降低了50.63%、13.23%和99.27%;Zn、Cr和Cu离子不能明显改变水化产物的微观形貌,但是会抑制氢氧化钙(CH)和钙矾石的生成和结晶。(2)当掺量低于1.0%时,蒸养混凝土对Zn和Cr离子具有很好地固化作用,浸出浓度均小于0.21 mg/L,但是Cu离子的浸出浓度高达0.92 mg/L以上。掺加20%粉煤灰的蒸养混凝土抗压强度会降低5~8 MPa,并不能提高其对重金属离子的固化性能。Considering its high early strength, mold transfer speed and production efficiency, steam curing concrete has become the main preparation technology of precast concrete. The mechanical properties, ion leaching test and X ray diffraction were used to investigated the effects of zinc, chromium and copper on the mechanical properties, hydration product structure and leaching characteristics of steam curing concrete. What＇s more, the effects of fly ash on solidification of heavy metal ions by steam curing concrete was also discussed. The results show that： ①Zn, Cr and Cu ions reduce the compressive strength of steam curing concrete in varying degrees. When the dosage of 1%, the compressive strength decreases by 50.63%, 13.23% and 99.27%, respectively. Zn, Cr and Cu ions can not significantly change the morphology of hydration products, but can inhibit the formation and crystallization of calcium hydroxide and ettringite. ②When the dosage is lower than 1%, the steam curing concrete have good solidification on Zn and Cr ions, the leaching concentration of which are less than 0.21 mg,/L, but the leaching concentration of Cu ion is as high as more than 0.92 mg./L. The compressive strength of steam curing concrete added with 20% fly ash is reduced by about 5 - 8 MPa, and the solidification of heavy metal ions can not be improved.

关 键 词：蒸养混凝土 重金属离子 抗压强度 固化 粉煤灰 

分 类 号：TU528[建筑科学—建筑技术科学]