Uniaxial Compression Tests of Sprayed Steel-Fiber-Reinforced Mortar

Qin YANG, Katsunori FUKUI, Seisuke OKUBO and Noriyuki TAKAMI

J. fo MMIJ, No.9, pp.655-661 (1997)

Steel-fiber-reinforced mortar (SFRM) or concrete (SFRC) is one of the future promising composite materials. SFRC can be sprayed easily and quickly on the wall of tunnel or gateway. Sprayed SFRM is especially suitable to todayﾕs rapid excavation by a tunnel boring machine, a boom header or a continuous miner.

In this study, uniaxial compression tests were performed controlling strain rate in air-dried condition. It was found that steel-fibers did not affect the peak strength and the pre-failure characteristics such as Youngﾕs modulus and Poissonﾕs ratio.

It is well known that a sprayed steel fiber is oriented parallel to the sprayed surface. When load was applied in the fiber oriented direction, no apparent effect of steel fibers was observed even in the post-failure region. When load was applied perpendicular to the fiber oriented direction, on the contrary, ductility and residual strength in the post-failure region considerably increased. An empirical equation was proposed to estimate the residual strength. Also, energy required to break a SFRM sample was obtained and discussed.

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