Title: Epoxy Adhesives for Steel Plate Bonding Applications

Author(s): Wolfgang O. Eisenhut

Publication: Symposium Paper

Volume: 165

Issue:

Appears on pages(s): 73-82

Keywords: adhesives; bonding; corrosion; epoxy resins; reinforcing steels; plates (structural members); repairs; Materials Research

DOI: 10.14359/1392

Date: 12/1/1996

Abstract:
Repair and strengthening of concrete structures by external reinforcement with steel plates affords the manufacturer of concrete adhesives an attractive new and potentially large opportunity for his products. In this application, bond lines are generally thicker and environmental effects more pronounced than in more traditional uses of such adhesives. In plate bonding, the adhesive becomes an integral part of the reinforcement system and must be capable of transferring stresses without lasting hysteresis effects. High modulus epoxy adhesives with high heat deflection temperatures (HDT) have been shown to have the necessary creep resistance and shear strength. In plate bonding, the internal steel surface is not protected against corrosion by the alkalinity of concrete. Corrosion resistant primers were found either to lack bond strength at high temperature or to enhance a reaction between the freshly prepared metal surface and the hardener component of the epoxy adhesives, which led to the use of unprimed steel plates. Unfilled, low viscosity resins appear to have better barrier properties against corrosion than filled pastes. Treatment of freshly prepared steel surfaces with certain silanes appears to retard flash rust formation as claimed in the literature.