再生微粉混凝土抗冻性及抗硫酸盐侵蚀性能研究

Study on Frost Resistance and Sulfate Resistance of Concrete with Recycled Fine Powder

浏览量:

关键词:

再生微粉;抗冻性能;抗硫酸盐侵蚀性能;扫描电镜;能谱分析

Key words:

Recycled fine powder; Frost resistance; Sulfate resistance; Scanning electron microscope; Energy spectrum analysis

刊期:

2020年3期   No.287   P27-30

DOI:

10.19761/j.1000-4637.2020.03.027.04

文章编号:

基金项目:

中国博士后基金(2016M602913);中建西部建设股份有限公司博士后课题。

作者:

张 平,古龙龙,李 凯,王子萌,卢 霄

单位:

中建西部建设新疆有限公司,乌鲁木齐 830000

摘要

摘   要:以28 d活性指数为85%的再生微粉按胶凝材料10%、20%、30%加入混凝土中,进行了再生微粉混凝土冻融循环试验及抗硫酸盐侵蚀性能研究。试验结果表明,再生微粉掺量低于20%时,掺量越高,混凝土的抗冻性能越好;通过SEM结果发现,混凝土冻融损坏是因水分子受冻膨胀导致钙矾石结晶裂缝和骨料与晶体间裂缝;再生微粉掺量越高混凝土抗硫酸盐侵蚀性能越低,且随着侵蚀时间的增加,该效果更加显著;EDS结果表明,干湿循环破坏的混凝土内部S元素急剧增加,形成的碳硫硅钙石膨胀导致混凝土内部产生结构裂缝是混凝土损伤的主要原因。
 
Abstract: Instead of regular class Ⅱ fly ash, the recycled fine powders with an activity index of 85% for 28 d were mixed in concrete, and the substitution rates were 10%、20%、30% of cementitious materials. The freeze-thaw cycle tests and micro performance of recycled fine powder concrete were carried out. The results show that when the recycled powder content is lower than 20%, the higher dosage, the better the Freeze-thaw resistance of concrete. The results of SEM indicate that the principle of freezing-thawing damage of concrete is that the water molecules expanded during freezing caused the crystal cracks of ettringite and the cracks between aggregates and crystals. The higher the content of recycled fine powder, the lower the resistance to  sulfate erosion of concrete. Through energy spectrum analysis, it is found that the S element in the concrete destroyed by the wet and dry cycle increases sharply, and the expansion of thaumasite causes cracks in the internal structure of the concrete.

结论

(1)再生微粉低于20%时,掺量越高,再生微粉混凝土抗冻性能越优,掺量大于20%时,再生微粉抗冻性能低于基准组。
 
(2)再生微粉混凝土抗冻等级与基准组一样,可达到F150,证明再生微粉掺量低于20%时,对混凝土抗冻性能略有提高。
 
(3)对于抗硫酸盐侵蚀性能,再生微粉掺量越高,硫酸侵蚀越严重,且混凝土受侵蚀越久混凝土破坏越严重。
 
(4)再生微粉混凝土更易与硫酸盐溶液形成碳硫硅钙石,使得混凝土内部发生膨胀,导致混凝土损伤。

参考文献

[1] 邓寿昌.建筑固体废弃物的循环利用与再生资源的可持续发展[A].同济大学、中国土木工程学会.首届全国再生混凝土研究与应用学术交流会论文集[C].同济大学、中国土木工程学会.2008,12.
 
[2] 胡智农,杨黎,刘昊.再生微粉混凝土耐久性研究[J].混凝土与水泥制品,2013(3):1-5.
 
[3] OTSUKI N.MIYAZATO S,YODSUDJAI W.Influence of recycled aggregate on interfacial transition zone,strength,chloride penetration and carbonation[J1.Journal of Materials in Civil Engineering,2003,15(5):443-451.
 
[4] 马郁. 掺建筑垃圾再生微粉混凝土性能试验研究[J]. 混凝土与水泥制品,2016(10):88-90.
 
[5] 陆总兵,陆健.对建筑材料循环利用技术及综合管理模式的探讨[J].管理观察,2017,21:56-58.
 
[6] 王金水.实现建筑垃圾资源化和循环利用[N].中国环境报,2014-01-27(002).
 
[7] 李建勇,马雪英,尚百雨,等.建筑废弃物再生微粉在混凝土中应用的试验研究[J].江西建材,2014(12):244-250.
 
[8] 石莹,杨善顺,连亚明.废弃混凝土再生微粉研究现状[J].砖瓦,2017(4):47-51.
 
[9] 方倩倩,於林锋,王琼.建筑垃圾再生微粉用于混凝土的试验研究[J].粉煤灰,2015,27(6):27-28+44.
 

引用本文

张平,古龙龙,李凯,等.再生微粉混凝土抗冻性及抗硫酸盐侵蚀性能研究[J].混凝土与水泥制品,2020(3):27-30.
 
ZHANG P,GU L L,LI K,et al.Study on Frost Resistance and Sulfate Resistance of Concrete with Recycled Fine Powder[J].China Concrete and Cement Products,2020(3):27-30.

上一个: 基于牺牲阳极法的LiBr改性砂浆性能研究

下一个: 无

相关文件