Title:
Loading Rate Effect on Pullout Behavior of Deformed Steel Fibers
Author(s):
Dong Joo Kim, Sherif El-Tawil, and Antoine E. Naaman
Publication:
Materials Journal
Volume:
105
Issue:
6
Appears on pages(s):
576-584
Keywords:
bond; fibers; matrix composition; pullout; rate sensitivity; strength
DOI:
10.14359/20199
Date:
11/1/2008
Abstract:
This paper describes the results of single-fiber pullout tests under various loading rates ranging from the static to the seismic level. Investigation of the loading rate effect on single-fiber pullout behavior provides a basis to better understand the effect of strain rate on the tensile properties of fiber-reinforced cement composites. Two types of high-strength deformed steel fibers (hooked and twisted fibers) known to have slip-hardening behavior under static pullout loading are evaluated. Experimental results reveal that the pullout response of twisted steel fibers shows rate sensitivity that is dependent on the compressive strength of the matrix. On the other hand, highstrength hooked fibers did not show rate sensitivity under pullout for the various matrixes tested. The test results also showed the pullout energy of twisted fibers increases with the matrix compressive strength and can be up to five times that of hooked fibers.