Comparative flexural behavior of four fiber reinforced cementitious composites

This research investigates the flexural behavior of fiber reinforced cementitious composites (FRCC) with four different types of fibers and two volume fraction contents (0.4% and 1.2%) within a nominally identical mortar matrix (56 MPa compressive strength). The four fibers are high strength steel twisted (T-), high strength steel hooked (H-), high molecular weight polyethylene spectra (SP-), and PVA-fibers. The tests were carried out according to ASTM standards. The T-fiber specimens showed best performance in almost all aspects of behavior including load carrying capacity, energy absorption capacity and multiple cracking behavior, while the PVA-fiber specimens exhibited comparatively the worst performance in all aspects of response. The only category in which SP-fiber specimens outperformed T-fiber specimens was deflection capacity, where SP-specimens exhibited the highest deflection at maximum load. By comparing the test results to data from an additional test program involving the use of a higher strength mortar (84 MPa) with both H- and T-fibers, it is shown that, again, T-fibers perform significantly better than H-fibers in a higher strength matrix. The test results from both experimental programs were used to critique the new ASTM standard [C 1609/C 1609M-05], and a few suggestions were made for improving the applicability of the standard to deflection-hardening FRCCs.