Static and dynamic mechanical behavior of engineered cementitious composites with PP and PVA fibers

Engineered cementitious composites (ECC) reinforced with oiled polyvinyl alcohol (PVA) fibers becomes more and more attractive in both research and engineering communities, while the PVA fibers-reinforced ECC (PVA-ECC) is of high cost due to the usage of the PVA fibers. One way to reduce the cost is to mix other economical fibers like polypropylene (PP) fibers with the PVA fibers. To prove the feasibility of hybrid PP and PVA fibers-reinforced ECC (PP-PVA-ECC), this paper presents a pilot study on static and dynamic properties (compression, tensile and impact resistance) of the PP-PVA-ECC and compared with those of PVA-ECC. PP-PVA-ECC specimens with three hybrid fiber volume ratios (0.5% PP+1.0% PVA, 1.0% PP+1.0% PVA, 1.5% PP+1.0% PVA) and PVA-ECC specimens with four fiber volume ratios (1.0%, 1.5%, 2.0% and 2.5%) were prepared. The axial static compression, tensile and drop-weight impact tests on the PP-PVA-ECC and the PVA-ECC with corresponding fiber volume ratios were conducted. The compression, tensile and impact performances of PP-PVA-ECC were studied and compared with those of PVA-ECC. The results indicated that the post-peak compression toughness, tensile strength, ultimate tensile strain, impact strength of PP-PVA-ECC increased significantly with the volume ratio of PP fibers. Results also showed that the PP-PVA-ECC performed slightly worse than the PVA-ECC with a given fiber volume ratio. The experimental evidences presented in the current study demonstrate the feasibility and plausible future of the novel hybrid PP-PVA-ECC.