Energy dissipation characteristics of all-grade polyethylene fiber-reinforced engineered cementitious composites (PE-ECC)

Systematical research was implemented to explore the impacts of fiber reinforcement index VfLf/d(f) (i.e., the product of fiber volume V-f and fiber aspect ratio L-f/d(f)) on the energy dissipation characteristics including strain energy density and fracture energy, of polyethylene fiber-reinforced engineered cementitious composites (PE-ECC) with compressive strength varying from normal to high. Six VfLf/d(f) values (i.e., 5, 7.5, 9, 10, 15, and 18) and five water/binder ratios (i.e., 0.14, 0.16, 0.18, 0.22, and 0.32) were considered in total. Strain energy density and fracture energy reflect the crack resistance capacity during the strain-hardening and softening processes of PE-ECC, respectively. The strain energy density of PE-ECC increased significantly with the increase of VfLf/d(f) and the decrease of water/binder ratio. The fracture energy increased noticeably with the growth of VfLf/d(f), while it attained the maximum value at the water/binder ratio of 0.16. For ECC including both the strain-hardening and softening processes, neither the strain energy density nor fracture energy alone can reflect its crack resistance capacity and energy dissipation capacity comprehensively. Thus, in the design and simulation processes of ECC, both energy parameters need to be considered in the constitutive model.