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Rebar pullout testing under dynamic Hopkinson bar induced impulsive loading

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Rebar pullout testing under dynamic Hopkinson bar induced impulsive loading

loading Mario Berra*, George Solomos** Rivista: Materials and Structures DOI 10.1617/s11527-009-9485-z Francia, 17 Febbraio 2009 * CESI RICERCA **EUROPEAN COMMISSION, JOINT RESEARCH CENTRE The dynamic behavior of the bond slip between a deformed reinforcing bar and plain concrete has been experimentally investigated by employing Hopkinson bar techniques. Pullout tests with various specimen types (unconfined, confined, cast-in-place, post-installed etc.) have been performed. Pullout of the steel rebar and splitting of the concrete cylinder have been the failure modes induced. Test results comprise peak pullout forces and complete bond stress–slip diagrams. They clearly show that the dynamic pullout forces and curves are well above the static ones, and that the pullout work of bond failure is considerably greater for the dynamic impact loading. Confinement, provided by a steel tube, leads to improved bonding; peak loads increase up to 2.5 times. The effects of bond length and concrete strength have also been put into evidence. Finally it has been verified that post installed rebars, depending upon the particular adhesive employed, can achieve the same bond resistance as the cast-in-place ones

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