A new concept for reducing deflection and crack width in FRP reinforced concrete structures

The modulus to strength ratio for both glass and carbon reinforced polymers is significantly less than that of steel. Therefore, the high strength of fibre reinforced polymer (FRP) bars is of little practical use in flexural members. In fact, by current practice, the usable strength of FRP in reinforced concrete is generally no ' more than 20 percent of its actual strength. To address this problem, in this investigation the concept of FRP prestressed tension elements (PTE) is introduced. Results of tests on PTE with cross sectional dimensions of 40 × 40 mm, and concentrically prestressed with FRP bars are presented. The prestressed elements are used as substitute for tension reinforcement in concrete beams. The results show that using PTE both deflection and crack width can be substantially reduced under service loads. Using this technique one takes full advantage of the strength of FRP in concrete structures.