Materials and Structures

, Volume 27, Issue 7, pp 375–382 | Cite as

Restrained shrinkage in repaired reinforced concrete elements

  • Ying-Su Yuan
  • Marton Marosszeky
Article

Abstract

This paper describes an analytical model of restrained shrinkage in repaired reinforced concrete elements. The results of analysis and test show that the effect of restrained shrinkage on the serviceability of the repaired element is quite significant. The computer based analysis proposed can be applied to predict progressive crack development in a repair material subjected to restrained shrinkage during construction. The properties of repair materials, such as ultimate strain in tension, creep coefficient and free shrinkage, are major factors influencing the performance of structural repairs. Restrained shrinkage is related to the stiffness of a repaired section of known structure. The effect of moment redistribution on restrained shrinkage is significant in elements of indeterminate structure. The stress and strain caused by restrained shrinkage in elements of indeterminate structure are higher than in elements of known structure, and an example given in this paper shows an increase in strain of about 30%.

Keywords

Shrinkage Strain Increment Styrene Butadiene Rubber Shrinkage Strain Concrete Element 

Resume

On décrit ici un modèle analytique de retrait empêché dans un élément de béton armé réparé. Les résultats de l'essai et de l'analyse montrent que l'influence du retrait empêché sur l'aptitude à l'emploi de l'élément est très significative. L'analyse informatisée proposée peut être utilisée pour prédire le développement progressif de fissures dans un matériau de réparation soumis au retrait empêché au cours de la construction. Les propriétés du matérau de réparation, telles que déformation ultime en traction, coefficient de fluage et retrait libre sont les facteurs essentiels qui influent sur la performance de la réparation structurelle. Le retrait empêché est en relation avec la rigidité de l'élément réparé dans une structure déterminée. L'influence de la redistribution des moments sur le retrait empêché est significative dans une structure indéterminée. La contrainte et la déformation occasionnées par le retrait empêché sont plus élevées dans une structure indéterminée que dans une structure déterminée, un exemple donné dans cet article fait apparaître un accroissement de 30% de la déformation.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Marosszeky, M. and Chew, M., ‘Site investigation of reinforcement placement on building and bridges,’Concr. Int. 12(4) (1990) 59–64.Google Scholar
  2. 2.
    Yuan, Ying-Su and Marosszeky, M., ‘Major factors influencing the performance of structural repair,’ in Proceedings of the ACI International Conference on Evaluation and Rehabilitation of Concrete Structures and Innovations in Design, Hong Kong, 1991, ACI-SP128, Vol. 2, pp. 819–837.Google Scholar
  3. 3.
    Birkeland, H. W., ‘Differential shrinkage in composite beams,’ACI J. 30 (May 1960) 1123–1136.Google Scholar
  4. 4.
    Yuan, Ying-Su. and Marosszeky, M., ‘Analysis of corroded reinforced concrete section for repair,’J. Struct. Engng 117 (1991) 2018–2034.Google Scholar
  5. 5.
    Marosszeky, M., Yu, J. G. and Ng, C. M., ‘The study of bond in concrete repairs,’ in Proceedings of the second CANMET/ACI International Conference on Durability of Concrete, Montreal, Canada, August 1991, ACI-SP126, pp. 1331–1354.Google Scholar
  6. 6.
    Hughes, B. P. and Chapman, G. P., ‘Direct tensile test for concrete using modern adhesives,’Mater. Struct. (1965).Google Scholar
  7. 7.
    Nagataki, S., Okamoto, T. and Suzuki, T., ‘A rational repair method for deteriorated reinforced concrete members,’ in Fourth International Conference on Durability of Building Materials and Components, Singapore, 1989, pp. 389–396.Google Scholar
  8. 8.
    Brüll, L., Komlos, K. and Majzlan, B., ‘Early shrinkage of cement pastes, mortars, and concretes,’Mater. Struct. 13(73) (1980) 41–45.Google Scholar
  9. 9.
    Yuan, Y. S., Gowripalan, N. and Marosszeky, M., ‘Structural repair of reinforced concrete elements,’ BRC Research Report (Building Research Centre, University of New South Wales, Australia, July, 1991).Google Scholar

Copyright information

© RILEM 1994

Authors and Affiliations

  • Ying-Su Yuan
    • 1
  • Marton Marosszeky
    • 2
  1. 1.School of Civil EngineeringChina University of Mining and TechnologyJiang SuP.R. China
  2. 2.School of BuildingUniversity of New South WalesAustralia

Personalised recommendations