Abstract

This paper presents the results of an experimental and analytical study conducted to assess the strengthening efficiency of a composite beam developed with the goal of simultaneously increasing the flexural stiffness and flexural strength of aging RC structures. A 4-point flexural test was performed on 12 RC beams that were 4.4 m in length. As test variables, the strengthening material (Type-A, B), epoxy type (organic epoxy, and inorganic epoxy), power pin interval (100, 200 mm), and cross-sectional size of the specimen (600 × 200 mm, 300 × 450 mm) were considered. Bond failure occurred in the specimen using inorganic epoxy, whereas in all of the other strengthened specimens, failure occurred as the result of composite beam fracture. The power pin interval and strengthening material type appeared to have very small impacts on the flexural strength of a strengthened RC beam, whereas the epoxy type and cross-sectional size of the specimen showed large impacts. In addition, the analysis model proposed for predicting the flexural behavior of a composite beam-strengthened RC beam was shown to provide relatively accurate predictions for the load-displacement behavior of a specimen in both the elastic and plastic sections.

Key words: Flexural test, composite beam, strengthening material, analysis model.