A comparative study on the compatibility of PVA and HTPP fibers with various cementitious matrices under flexural loads

The compatibility of polyvinyl alcohol (PVA) and high tenacity polypropylene (HTPP) fibers with various cementitious matrices in terms of bending performance has been investigated. Matrices were prepared at three water to binder (W/B) ratios. In order to compare the flaw tolerancy of matrices, natural flaw structure of half of the specimens were modified by using poly-ethylene beads (at 3 mm diameter). The effects of fiber type, water/binder (W/B) ratio and flaw structure modification on the multiple-cracking behavior of bending composites were determined under flexural loads. The matrix phase of composites is mainly composed of ordinary Portland cement (OPC), Metakaolin (M), and limestone powder, respectively. Prismatic specimens (25 × 60 × 300 mm) have been prepared and subjected to 4-point loading test 28 days after specimen preparation. Flexural properties, multiple cracking potentials, crack properties (by means of number and width) of composites were compared. Results showed that, HTPP fibers seem more advantageous compared to PVA fibers in terms of flaw tolerancy with metakaolin based matrices.