Analysis of Microstructure of Interfacial Transition Zone (ITZ) in Recycled Aggregate Concrete

Abstract:

Experiments on influence of species of aggregate and mixing method on interfacial zone in recycled aggregate concrete were investigated. SEM observations revealed that a recycle normal-strength concrete aggregate consist of loose and porous interfacial structure, whereas a recycled high performance concrete (HPC) aggregate and a triple mixing (TM) consist mainly of dense hydrates. Various admixtures on ITZ was produced that consumed CH in the pore, modified attached cement mortar. Strength of recycled concrete was explained by interaction between cements paste and recycled aggregate. The result verified that the relatively dense pore structure of the recycled concrete benefit to development of mechanical properties.

• Periodical: Advanced Materials Research (Volume 811)
• Pages: 249-253
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.811.249
• Online since: September 2013
• Authors: Wei Li, Hai Ying Zhang
• Keywords: Interfacial Transition Zone, Microstructure, Recycled Aggregate (RA)

References

[1] T.C. Hansen, E & FN Spon, Recycling of Demolished Concrete and Masonry, RILEM Report 6, UK, (1992).

[2] Olorunsogo FT, Padayachee N., Performance of recycled aggregate concrete monitoring by durability indexes, Cem Concr Res 32(2002)179 -85.

DOI: 10.1016/s0008-8846(01)00653-6

[3] S.C. Kou, C.S. Poon, Enhancing the durability properties of concrete prepared with coarse recycled aggregate, Construction and Building Materials 35 (2012) 69-76.

DOI: 10.1016/j.conbuildmat.2012.02.032

[4] Sagoe-Crentsil KK, Brown T, Taylor AH, Performance of concrete made with commercially produced coarse recycled concrete aggregate, Com Concr Res. 31(2001)707-712.

DOI: 10.1016/s0008-8846(00)00476-2

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

DOI: 10.1016/j.conbuildmat.2004.03.005

[6] D. Kong, T Lei, J Zheng et al, Effect and mechanism of surface-coating pozzalanics materials around aggregate on properties and ITZ microstructure of recycled aggregate concrete, Construction and Building Material. 24(2010) 701-708.

DOI: 10.1016/j.conbuildmat.2009.10.038

[7] V.W.Y. Tam, C.M. Tam, K.N. Le, Removal of cement mortar remains from recycled aggregate using pre-soaking approaches, Resources, Conservation and Recycling 50 (2007) 82–101.

DOI: 10.1016/j.resconrec.2006.05.012