Study on Effect of Performance of Recycled Aggregate Concrete with Secondary Manufacturing Shell Mixing Approach

Abstract:

The application of recycled aggregate concrete (RAC) has environmental benefits, social benefits and economic benefits, which has profound significance to the sustainable development of society. However, recycled aggregate (RA) has a large porosity, high water absorption, high crush index, etc. In addition, the interface transition zone (ITZ) is the weak link of RAC, which has limited the application of RAC. Based on the advance of RAC, by discussing the characteristic of the ITZ of RAC, this paper proposes a secondary manufacturing shell mixing approach (SMSMA), and the mechanism of this mixing approach and its effect on performance of RAC are analyzed. Compared with the test of normal mixing approach (NMA), it indicates that compressive strength and splitting tensile strength of RAC through SMSMA are generally increased by about 10% ~ 25% and 10% ~ 40% at 28 days respectively, and the chloride ion diffusion coefficient are generally declined by about 10% ~ 15% at 28 days, but the liquidity of RAC is not improved. What's more, with replacement rate of RA dropping, the improvement of the performance of RAC tends to be better.

• Periodical: Advanced Materials Research (Volume 1020)
• Pages: 80-85
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.1020.80
• Online since: October 2014
• Authors: Jing Bo Mu, Ya Qian Cui
• Keywords: Interfacial Transition Zone, Mixing Approach, Recycled Aggregate Concrete, Secondary Manufacturing Shell

References

[1] Shui Zhonghe, Pan Zhisheng, Zhu Wenqi, Microstructural characteristics of recycled aggregate concrete, J. Journal of Wuhan University of Technology. 2003, 28 (12) 99-102.

[2] Poon. C S, Shui Z H, Lam L, Effect of microstructure of ITZ on compressive strength of concrete prepared with recycled aggregates, J. Construction and Building Materials, 2004 (18) 461-468.

DOI: 10.1016/j.conbuildmat.2004.03.005

[3] Rejeb Saeed Khalaf, Improving compressive strength of concrete by a two-step mixing method, J. Cement and Concrete Research, 1996, 26 (4) 585-592.

DOI: 10.1016/0008-8846(96)00030-0

[4] Sun Chengcheng, Yuan Dong, Song Jianxue, Study on effect of compressive strength of recycled aggregate concrete with secondary mixing process, J. Concrete, 2008(6)125-128.

[5] J.S. RYU, Improvement on strength and impermeability of recycled concrete made from crushed concrete coarse aggregate, J. Journal of Materials Science Letters, 2002(21)1565-1567.

[6] Vivian W Y Tam, Gao X F, Tam C M, Microstructural Analysis of Recycled Aggregate Concrete Produced From Two-Stage Mixing Approach, J. Cement and Concrete Research, 2005, 35 (6) 1195－1203.

DOI: 10.1016/j.cemconres.2004.10.025

[7] Vivian W Y Tam, Tam C M, Wang Y, Optimization on Proportion for Recycled Aggregate in Concrete Using Two-Stage Mixing Approach, J. Construction and Building Materials, 2007 (21)1928－(1939).

DOI: 10.1016/j.conbuildmat.2006.05.040