Title:
Tensile Postcrack Behavior of Steel Fiber Reinforced Ultra-High Strength Concrete
Author(s):
Claus V. Nielsen
Publication:
Symposium Paper
Volume:
159
Issue:
Appears on pages(s):
231-246
Keywords:
ductility; fiber reinforced concretes; high-strength concretes; strength; tension tests; Materials Research
DOI:
10.14359/1384
Date:
2/1/1996
Abstract:
Approximately 30 direct tensile tests have been performed on so-called Compresit matrix. This matrix is based on micro silica particles compacted in between the cement particles. The dense matrix, which shows high brittleness, is provided with ductility by means of steel fibers mixed randomly with respect to both position and orientation. Compressive strengths reaching 200 MPa are experienced with this particular matrix. The fiber reinforcement index is varied throughout the test series by means of three different fiber geometries and contents. Besides a plain mix without any fibers, the fiber reinforcement index is varied from 0.9 to 3.6, which is a wide range compared to other fiber reinforced concrete investigations. The test results consist of measured bridging stresses versus crack widths after the initiation of the first crack. A micro-mechanical model developed by V.C. Li, et al., is evaluated and compared to the results. This model agrees with low and moderate contents of both steel fibers and synthetic fibers. It is concluded that the micro-mechanical prediction does not seem to be sufficient to model the post-crack behavior of high-strength matrix reinforced with high amounts of steel fibers. However, the post-crack strength provided by the fibers crossing a crack plane is modeled satisfactorily.