Chloride Distribution Feature in Surface Layer of Cement Paste under Cyclic Drying-Wetting Condition

Abstract:

This research focuses on chloride distribution in the surface layer of cement paste and the relation between chloride distribution and pore structure under two different drying-wetting regimes. The results of chloride profiles obtained by three different methods reveal that it dose exist a feature that chloride content first gose up then down with a maximum value C_max appearing in the homogeneous surface layer of cement paste subjected to indoor cyclic dry-wet condition. Besides, the C_max increases with the ratio of water to cement (W/C) increasing. And the regime with higher drying temperature and longer wetting time leads to higher C_max. Moreover, C_max appears at the same location for both total and free chloride. In addition, C_max increases with total porosity, the most probable pore size, and average radius increasing, while it decreases with tortuosity decreasing.

• Periodical: Key Engineering Materials (Volume 711)
• Pages: 367-374
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.711.367
• Online since: September 2016
• Authors: Hong Lei Chang*, Song Mu, Jian Zhong Liu
• Keywords: Cement Paste, Chloride Distribution Feature, Cyclic Drying-Wetting Condition, Maximum Chloride Content, Pore Structure

References

[1] Hwan-Oh B, Yup Jang S. Effects of material and environmental parameters onchloride penetration profiles in concrete structures. Cement and Concrete Research2007; 37(1): 47-53.

DOI: 10.1016/j.cemconres.2006.09.005

[2] Mehta PK. Concrete: structure, properties and materials. Ed Prentice-Hall; 1986. pp.105-169.

[3] Khelidj A, Loukili A, Bastian G. Experimental study of the hydro-chemicalcoupling inside maturing concretes: effect on various types of shrinkage. Materials andStructures 1998; 31(9): 588-94.

DOI: 10.1007/bf02480608

[4] Nielsen EP, Geiker MR. Chloride diffusion in partially saturated cementitiousmaterial. Cement and Concrete Research 2003; 33(1): 133-8.

DOI: 10.1016/s0008-8846(02)00939-0

[5] Rob B. Polder, Willy H.A. Peelen. Characterization of chloride transport and reinforcement corrosion in concrete under cyclic wetting and drying by electrical resistivity. Cement & Concrete Composites 2002; 24: 427-435.

DOI: 10.1016/s0958-9465(01)00074-9

[6] Amor Ben Fraj, Stéphanie Bonnet, Abdelhafid Khelidj. New approach for coupled chloride/moisture transport in non-saturated concrete with and without slag. Construction and Building Materials 2012; 35: 761-771.

DOI: 10.1016/j.conbuildmat.2012.04.106

[7] H. Kuosa, R.M. Ferreira, E. Holt, M. Leivo, E. Vesikari. Effect of coupled deterioration by freeze–thaw, carbonation and chlorides on concrete service life. Cement & Concrete Composites 2014; 47: 32-40.

DOI: 10.1016/j.cemconcomp.2013.10.008

[8] K. Tuutti. Corrosion of steel in concrete[M]. Sweden, CBE Forskning fo 4. 82 (Swedish Cement and Concrete Research Institute Stockholm), (1982).

[9] Zhiwu Yu, Ying Chen, Peng Liu, Weilun Wang. Accelerated simulation of chloride ingress into concrete under drying-wetting alternation condition chloride environment. Construction and Building Materials 2015; 93: 205-213.

DOI: 10.1016/j.conbuildmat.2015.05.090

[10] A. Costa, J. Appleton. Chloride penetration into concrete in marine environment-Part I: Main parameters affecting chloride penetration. Materials and Structures 1999; 32: 252-259.

DOI: 10.1007/bf02479594

[11] Crank J. The mathematics of diffusion, 2nd edn. Clarendon Press, Oxford; (1986).

[12] Bamforth PB, Price WF, Emerson M (1997). An internationalreview of chloride ingress into structural concrete. Transport Research Laboratory, Taywood Engineering LTD., Contractor Report 359, pp.95-114.

[13] Carmen Andrade, Jose Miguel Dı´ez, Cruz Alonso. Mathematical Modeling of a Concrete Surface Skin Effect, on Diffusion in Chloride Contaminated Media. Advanced Cement Based Material 1997; 6: 39-44.

DOI: 10.1016/s1065-7355(97)00002-3

[14] Chanakya Arya, Samira Bioubakhsh, Perry Vassie. Chloride penetration in concretesubject to wet–dry cycling: influence of pore structure. Structures and Buildings 2014; 167 (SB6): 343-354.

DOI: 10.1680/stbu.12.00067

[15] Chanakya Arya, Perry Vassie, Samira Bioubakhsh. Chloride penetration in concretesubject to wet/dry cycling: influence of moisture content. Structures and Buildings 2014; 167(SB2): 94-107.

DOI: 10.1680/stbu.12.00027

[16] K. Hong, R.D. Hooton. Effects of cyclic chloride exposure on penetration of concrete cover. Cement and Concrete Research 1999; 29: 1379-1386.

DOI: 10.1016/s0008-8846(99)00073-3

[17] Tuutti K. Analysis of pore solution squeezed out of cement andmortar. Nordic Concrete Research 1982; 1: 25. 1-16.