Repairs to reinforced concrete beams suffering from chloride-induced corrosion necessitate breaking out concrete around reinforcement. Reinforcement and concrete cannot act compositely where bars are exposed, and the pattern of strains in a beam under load is altered. The present study evaluates postrepair structural performance of reinforced-concrete beams repaired when relieved of load and when repaired under load and using a variety of alternative approaches to maintain structural stability during repair operations. Two series of four or five beams each were loaded and subjected to simulated repair in the laboratory. A reference "as-new" beam was also tested in each series for comparison. The ultimate strength of beams repaired under load was not reduced in comparison with "as-new" companion specimens, although ductility, deflection, crack widths, and flexural stiffness were all affected. However, results do not suggest significant benefits in postrepair performance will be obtained through relieving a structure of load or from application of temporary longitudinal prestress while repairs are carried out. For beams repaired under load, two stage repairs (in which only half the reinforcement at a section is exposed at any one time) offered little overall improvement over single-stage repairs in which all bars were exposed simultaneously.
|Number of pages||9|
|Journal||Journal of Structural Engineering|
|Publication status||Published - Mar 1996|