Experimental Study on Deformation Behavior of Polypropylene Fiber Reinforced Concrete Beams

In order to explore the difference in deformation behaviors of polypropylene engineered cementitious composite (PP-ECC) beam and reinforced concrete (RC) beam, bending resistance tests were performed on four PP-ECC beams and four RC beams using two loading systems, i.e., step loading and cyclic loading. Meanwhile, based on the effective moment of inertia method, the maximum deformation calculation formula applicable to the PP-ECC beams under short-term loads was derived. The results show that the PP-ECC beam undergoes a more obvious plastic deformation stage under successive loading. Compared with the RC beam, the deformation curve of the PP-ECC beam after 5 cycles of cyclic loading fits better with the original curve. During cyclic loading, the growth rates of the loading and unloading deformation of PP-ECC beams under the reference load are both lower than those of RC beams with the same reinforcement ratio, showing better damage resistance and deformation recovery ability. In general, the calculated results of deformation correction model based on the effective moment of inertia method fit well with the test results, and the proposed method can be applied to the calculation of maximum deformation of PP-ECC beams under short-term load in practical engineering.