Flexural behavior of aluminum I-beams strengthened by pre-stressed CFRP tendons

To improve the flexural rigidity and load carrying capacity, aluminum I-beams were retrofitted by pre-stressed carbon fiber reinforced plastic (CFRP) tendons. Three pre-stress schemes were proposed. Four-point-bending experiments were carried out to reveal the flexural behaviors and failure styles of the strengthened beams. Flexure of the pre-stressed beam is greatly reduced due to arch effect and increased flexural rigidity. Increasing the pre-stress level, the flexure gets even smaller. Yield load of the pre-stressed beam is enhanced at a level of 33.3%. CFRP pre-stressing schemes greatly improve the failure load of the aluminum I-beam, which fails at plastic lateral-torsional buckling. The improvement is about 52.3% in this research.