Investigation on Failure Mechanism of Nanomodified Recycled Aggregate Concrete

被引：0
|
作者：
Li W. [1 ,2 ]
Long C. [1 ]
Luo Z. [1 ]
Huang Z. [1 ]
机构：
[1] College of Civil Engineering, Hunan University, Changsha
[2] School of Civil and Environmental Engineering, University of Technology Sydney, Sydney
来源：
| 1600年 / Tongji University卷 / 20期
关键词：
Crack propagation; Failure mechanism; Interfacial transition zone (ITZ); Nanomaterial; Recycled aggregate concrete (RAC);
D O I：
10.3969/j.issn.1007-9629.2017.05.005
中图分类号：
学科分类号：
摘要：
The crack evolution of recycled aggregate concrete (RAC) and the performance of RAC after incorporation of different amount of nanoparticles (nanosilica sol and nanolimestone) were studied. Under uniaxial compression, the crack development of RAC specimens with different water-cement ratios (0.4, 0.5 and 0.6) and aggregate replacement ratios were observed by high speed camera. Scanning electron microscopy (SEM) observation and mercury injection test were conducted for studying the microscopic morphology and pore structure of the interfacial transition zone (ITZ) of nanomodified RAC and the influences of different mass fraction of nanoparticles and different treatment processes on it were analyzed. The results indicate that the crack of RAC is usually derived from new ITZ or old ITZ (determined by the weaker one) and then it gradually extends to the surrounding area. The evolution of crack eventually leads to the longitudinal splitting failure of the RAC. Nanosilica sol could improve the microstructure of ITZ. Therefore, the strength of nanosilica sol modified RAC was enhanced. But the improvement by nanolimestone is not very significant for it can't enter the interface transition zone to fill the pore in it. © 2017, Editorial Department of Journal of Building Materials. All right reserved.
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页码：685 / 691and786
相关论文
共 16 条
  • [1] Tam V.W.Y., Gao X., Tam C.M., Microstructural analysis of recycled aggregate concrete produced from two-stage mixing approach, Cement and Concrete Research, 35, 6, pp. 1195-1203, (2005)
  • [2] Sidorova A., Vazquez-Ramonich E., Barra-Bizinotto M., Et al., Study of the recycled aggregates nature's influence on the aggregate-cement paste interface and ITZ, Construction and Building Materials, 68, pp. 677-684, (2014)
  • [3] Xiao J., Li J., Sun Z., Study on compressive strength of recycled concrete, Journal of Tongji University (Nature Science), 32, 12, pp. 1558-1561, (2004)
  • [4] Li J., Xiao J., Huang J., The effect of recycled coarse aggregate to concrete compressive strength, Journal of Building Materials, 9, 3, pp. 297-301, (2006)
  • [5] Zhang X., Deng S., Deng X., Et al., Experimental research on a few main factors influencing strength of the recycled concrete, Journal of Xiangtan University (Natural Science), 27, 1, pp. 129-133, (2005)
  • [6] Poon C.S., Shui Z.H., Lam L., Effect of microstructure of ITZ on compressive strength of concrete prepared with recycled aggregates, Construction and Building Materials, 18, 6, pp. 461-468, (2004)
  • [7] Ong G.K.C., Akbamezhad A., Zhang M.H., Et al., Mechanical properties of concrete incorporating microwave-treated recycled concrete aggregates, 35th Conference on Our World in Concrete & Structures, pp. 1-9, (2010)
  • [8] Kou S.C., Poon C.S., Properties of concrete prepared with PVA-impregnated recycled concrete aggregates, Cement and Concrete Composites, 32, 8, pp. 649-654, (2010)
  • [9] Grabiec A.M., Klama J., Zawal D., Et al., Modification of recycled concrete aggregate by calcium carbonate biodeposition, Construction and Building Materials, 34, pp. 145-150, (2012)
  • [10] Shi C., Li Y., Zhang J., Et al., Performance enhancement of recycled concrete aggregate-A review, Journal of Cleaner Production, 112, pp. 466-472, (2016)
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