Browse > Article
http://dx.doi.org/10.4334/JKCI.2011.23.5.647

Characteristics of Pore Structures and Compressive Strength in Calcium Leached Concrete Specimens  

Yang, Eun-Ik (Dept. of Civil Engineering, Gangneung-Wonju National University)
Choi, Yoon-Suk (Dept. of Civil Engineering, Gangneung-Wonju National University)
Publication Information
Journal of the Korea Concrete Institute / v.23, no.5, 2011 , pp. 647-656 More about this Journal
Abstract
In radioactive waste repositories constructed in underground, concrete member could be in contact with groundwater for a long time. However, this pure water creates concentration gradients which lead to the diffusion of Ca ions from the pore water and the degradation of underground concrete. Therefore, this study is aimed at investigating the alteration of pore structure and loss of compressive strength associated with dissolution. The results showed that as the leaching period became longer, the pore volume within 50 nm to 500 nm in diameter is greatly increased. Also, the volume of pores larger than 200 nm rapidly increased during initial leaching time and those below 200 nm gradually increased. Furthermore, the compressive strength gradually decreased with increase of degraded thickness. The residual strength of the degraded concrete with OPC was in the range of 33% to 58%.
Keywords
calcium leaching; micropore structure; strength; radioactive waste repository; concrete degradation;
Citations & Related Records
Times Cited By KSCI : 1  (Citation Analysis)
연도 인용수 순위
1 ASTM International, "Standard Test Method for Microscopical Determination of Parameters of the Air-Void System in Hardened Concrete," ASTM C 457, West Conshohocken, PA, 2010, 1022 pp.
2 ASTM International, "Standard Test Method for Determining Pore Volume Distribution of Catalysts by Mercury Intrusion Porosimetry," ASTM D 4284, West Conshohocken, PA, 2007, 650 pp.
3 이창수, 이규동, 국부승랑, 곽도연, "양생온도와 재령에 따른 콘크리트 공극 구조 특성 변화와 압축강도와의 관계," 대한토목학회 논문집, 24권, 6A호, 2004, pp. 1145-1150.
4 Carde, C. and François, R., "Modelling the Loss of Strength and Porosity Increase due to the Leaching of Cement Pastes," Cement & Concrete Composites, Vol. 21, No. 3, 1999, pp. 181-188.   DOI   ScienceOn
5 Saito, H. and Nakane, S., "Comparison between Diffusion Test and Electrochemical Acceleration Test for Leaching Degradation of Cement Hydration Products," ACI Materials Journal, Vol. 96, No. 2, 1999, pp. 208-213.
6 Carde, C., Escadeillas, G., and François, R., "Use of Ammonium Nitrate Solution to Simulate and Accelerate the Leaching of Cement Pastes due to Deionized Water," Magazine of Concrete Research, Vol. 49, No. 181, 1997, pp. 295-301.   DOI   ScienceOn
7 Haga, K., Shibata, M., and Hironaga, M., "Change in Pore Structure and Composition of Hardened Cement Paste During the Process of Dissolution," Cement and Concrete Research, Vol. 35, No. 5, 2005, pp. 943-950.   DOI   ScienceOn
8 Haga, K., Sutou, S., and Hironaga, M., "Effect of Porosity on Leaching of Ca from Hardened Ordinary Portland Cement Paste," Cement and Concrete Research, Vol. 35, No. 9, 2005, pp. 1764-1775.   DOI   ScienceOn
9 Carde, C. and François, R., "Effect of ITZ Leaching on Durability of Cement-Based Materials," Cement and Concrete Research, Vol. 27, No. 7, 1997, pp. 971-978.   DOI   ScienceOn
10 Saito, H. and Deguchi, A., "Leaching Tests on Different Mortars Using Accelerated Electrochemical Method," Cement and Concrete Research, Vol. 30, No. 11, 2000, pp. 1815-1825.   DOI   ScienceOn
11 Torrenti, J. M., Nguyen, V. H., and Colina, H., "Chemo-Mechanical Coupling Behaviour of Leached Concrete Part I: Experimental Results," Nuclear Engineering and Design, Vol. 237, Nos. 20-21, 2007, pp. 2083-2089.   DOI   ScienceOn
12 Skoczylas, F., Agostini, F., and Lafhaj, Z., "Experimental Study of Accelerated Leaching on Hollw Cylinders of Mortar," Cement and Concrete Research, Vol. 37, No. 1, 2007, pp. 71-78.   DOI   ScienceOn