Microstructure model of the interfacial zone between fresh and old concrete

Abstract

A new model of repaired concrete which divides the bonding interface into a penetrating layer, a strongly-affected layer and a weakly-affected layer was put forward. The model is mainly based on the observation of the microstructure of interface between fresh and old (3 months to 60 years) concretes by using scanning electron microscopy. Then, the mechanism of the microstructure formed was analyzed. Finally, the relationship between the micro-structure and macro-mechanical performance of the interface was discussed. V 3

Keywords

microstructure of the interface / bonding model / repairing of concrete

References

[1] Yuan Y S, Marosszeky M. Major Factor Influence the Performance of Structural Repair, Evaluation and Rehabilitation of Concrete Structures and Innovations in Design—Proceedings. ACI International Conference, Hong Kong, 1991, 128–50: 820-837.

[2] Plum D R. The Behaviour of Polymer Materials in Concrete Repair, and Factors Influencing Selection. The Structural Engineer, 1990, 68(17): 337-345.

[3] Carles-Gibergues A, Saucier F, Grander J, Pigeon M. New-to-Old Concrete Bonding: Influence of Sulfates Type of New Concrete on Interface Microstructure. Cement and Concrete Research, 1993, 23: 431-441.

[4] Guang Daqing, Chen Zhanghong. The Influence of Interface Handle to the Bonding Performance of New-old Concrete. Concrete, 1994, 5: 16-22.

[5] Barnes P.Structure and Performance of Cement. Publishers LTD, 1983

[6] Bijen J, Salet T. Folker H W. Adherence of Young Concrete to Old Concrete —Development of Tools for Engineering. Adherence of Young on Old Concrete, 1993, Switzerland: Published by ASMES.

[7] Chatterji S, Jeffery I W. Studies of Early Stages of Paste Hydration of Cement Compounds. J. Am. Ceram. Soc., 1963, 46: 187-191.

[8] Guo C. Early-age Behaviour of Portland Cement Paste. ACI Mater. J., 1994, 91: 13-25.