Flexural behavior of concrete beams strengthened with steel reinforced polymers

ABSTRACT

The successful application of composites for structural upgrade has motivated the development of other novel low-cost reinforcement systems that exhibit excellent structural properties. The ability to put very high tensile strength steel into a fabric that can be incorporated into composites was one of the particular interests to the engineering communities worldwide. This paper examines the feasibility and potential of using high-strength steel reinforced polymers (SRP) to strengthen reinforced concrete beams. A total of seven concrete beams (150x300x3000 mm) were constructed and tested under four point bending to evaluate the effectiveness of the strengthening scheme. The influence of the type of the bonding agent, number of plies and the arrangement of the U-wraps along the length of the concrete beams is investigated. Test results showed that SRP could improve both the flexural stiffness and the ultimate load carrying capacity considerably. The flexural capacity was increased by more than300% sing multiple plies of SRP sheets. For the majority of the tested beams, failure was dominated by delamination of the sheets from the concrete surface. Using U-wraps along the length of the beam prevented this type of failure and allowed full utilization of the tensile strength of the sheets.