Title: Laboratory Investigation of Shear Repair of Reinforced Concrete Beams Loaded in Flexure

Author(s): Frank Collins and Harold Roper

Publication: Materials Journal

Volume: 87

Issue: 2

Appears on pages(s): 149-159

Keywords: beams (supports); bonding; epoxy resins; flexural strength; loads (forces); post-tensioning; repairs; shear strength; strengthening; tests; Materials Research

DOI: 10.14359/1964

Date: 3/1/1990

Abstract:
The structural rehabilitation of reinforced concrete beams in shear was studied, with particular attention paid to resin injection. Other shear repair techniques that were examined include post-tensioning in shear, bar bonding, and stitching. Emphasis was placed on the influence of damage across the repair interface due to unloading while propping during the repair stage. A series of model beams, unreinforced in shear, were loaded in the laboratory until a major diagonal tension crack developed on both shear spans. Individual beams were unloaded to a set proportion of that load, repaired, and again loaded to failure. Scaled field-size beams were also tested. The repair strength achieved for resin-injected reinforced concrete beams was shown to be influenced by the condition of the major diagonal crack after initial damage. This conclusion was supported by surface strain measurements, load-deflection data, and crack measurements.