Original Paper(Vol.60 No.4 pp.325-331)

Fracture of Polyethylene Fiber Reinforced Mortar under High-Velocity Projectile Impact

Masayoshi YAMADA, Yasuhiro TANABE and Minoru KUNIEDA

Abstract:Fiber reinforced mortar is expected to be used for the construction of the external walls of buildings, and in particular, pedestal required to operate magnetic levitated trains because of its nonmagnetism. Although many impact experiments for concrete and armored concrete have been reported thus far, few impact experiments for fiber reinforced mortar have been reported. In this study, we determined the effect of polyethylene (PE) fiber contained in mortar on the fracture behavior. A spherical SUJ2-steel projectile (diameter: 4 mm, mass: 0.26 g) was accelerated using a one-stage light gas accelerator and a two-stage light gas accelerator such that it would impact the test specimens at an impact velocity ranging from 200 - 1100 m/s. All the specimens used for the impact tests had dimensions of 75 mm ~ 75 mm and a thickness of 11.5 mm. Three kinds of specimens were used and contained PE fiber from 0% to 1.5%. The use of PE fibers in mortar effectively affected the generation of radial cracks, cone slope angle and ballistic limit. On the other hand, it did not affect the absorbed energy.@Formulation of ballistic limit indicated that PE fiber reinforced mortar was able to be adapted formulation of ballistic limit which was used for armored concrete.

Key Words:Mortar, Polyethylene fiber, Impact, Projectile, Fracture phenomena, Cone crack