Title: The Influence of Injected Epoxy Systems on the Elastic and Mechanical Properties of Cracked Concretes

Author(s): G. Moriconi, M. G. Pauri, G. Percossi, and S. Busto

Publication: Symposium Paper

Volume: 128

Issue:

Appears on pages(s): 233-248

Keywords: Cracking(fracturing); elastic properties; epoxy resins; impregnating; mechanical properties; strength; viscosity

DOI: 10.14359/10020

Date: 11/1/1991

Abstract:
An investigation was carried out to evaluate the effectiveness of epoxy systems injected into cracks in concrete in order to repair damaged concrete structures. It was found that the usual parameters (viscosity, elastic modulus) characterizing epoxy system are not sufficient for such an evaluation, since concrete microstructure and crack width are determinant factors. Successful1 injection into larger macrocracks (>0,8 mm) is independent of the epoxy system viscosity. However, for narrower cracks (< O,3 mm), the effectiveness of the injection strongly depends on the viscosity of the epoxy system, so that a threshold value of viscosity can be determined for each microcrack width. The injection of epoxy systems into cracks of porous concretes causes, in addition to the crack filling, an impregnation of the material surrounding the crack area. This impregnation causes a strength increase, which is higher for more porous concretes and higher epoxy system viscosity. The mechanical behaviour of injected concretes do not depend significantly on the mechanical properties of the epoxy system, whereas the rheological properties of the epoxy system can affect the performances of injected concretes.