Pull-out behavior of prestressing strands in steel fiber reinforced concrete

This paper presents the results of an experimental study investigating the effects of steel fibers on the mechanical properties of concrete and the enhancement of bond strength of prestressing strands in steel fiber reinforced concrete (SFRC). The first part of the experimental program consisted of compression, tension and flexural tests on SFRC. Two types of steel fibers with 30 mm and 60 mm fiber lengths were used with five different fiber contents. The second part of the study consisted of simple pull-out tests on 12.7 mm and 15.2 mm diameter seven-wire untensioned prestressing strands embedded in concrete blocks. The pull-out tests were conducted with two different fiber lengths and five different fiber contents for each strand diameter. The steel fibers were observed to improve the pull-out resistance of strands by controlling the crack growth inside concrete blocks.

► Compression, tension, flexural and pull-out tests were performed on SFRC.
► The parameters investigated were fiber geometry, fiber content and strand diameter.
► The pull-out resistance of strands was improved by the steel fibers.
► The steel fibers controlled the crack growth inside concrete blocks.