Abstract
This work presents the results of a research project aimed at assessing the correlation among fresh state behavior mechanical properties in the hardened state and fiber dispersion in steel fiber reinforced concretes. Three fiber reinforced concretes were hence designed and targeted to different levels of fresh state performance: a vibrated concrete, a self consolidating one and a third exhibiting segregation. Fiber reinforcement consisted in all cases of 50 kg/m3 hooked end steel fibers, 35 mm long and with an aspect ratio equal to 65. Square plates 600 mm wide and 60 mm thick were cast for each mix. The dispersion of fibers within the specimens was investigated through Alternate Current Impedance Spectroscopy (AC-IS). Finally, beams were cut from the plates and tested in 4-point bending. From the load-crack-opening and load-deflection response toughness and stiffness parameters were computed to assess the behavior at serviceability and ultimate limit states. The influence of fiber dispersion and orientation in thin plates on the measured mechanical properties is discussed and a correlation is attempted with parameters, such as fiber spacing, suitably defined to represent the dispersion, detected as above. The results clearly highlight the connections existing between fresh state behavior, fiber dispersion and mechanical properties of SFRC, pointing out their importance for a design of the material composition as well as of the casting process “tailored” to the specific structural application.
| Original language | English (US) |
|---|---|
| Title of host publication | Deflection and Stiffness Issues in FRC and Thin Structural Elements |
| Editors | Peter H. Bischoff, Faris Malhas |
| Publisher | American Concrete Institute |
| Pages | 83-100 |
| Number of pages | 18 |
| ISBN (Electronic) | 9780870312571 |
| State | Published - Sep 1 2007 |
| Event | Deflection and Stiffness Issues in FRC and Thin Structural Elements 2007 at the ACI Fall 2007 Convention - Fajardo, Puerto Rico Duration: Oct 14 2007 → Oct 18 2007 |
Publication series
| Name | American Concrete Institute, ACI Special Publication |
|---|---|
| Volume | SP-248 |
| ISSN (Print) | 0193-2527 |
Conference
| Conference | Deflection and Stiffness Issues in FRC and Thin Structural Elements 2007 at the ACI Fall 2007 Convention |
|---|---|
| Country/Territory | Puerto Rico |
| City | Fajardo |
| Period | 10/14/07 → 10/18/07 |
Funding
This work has been performed during a period spent by the first author at ACBM, Northwestern University, in the framework of a Fulbright Program, whose support is gratefully acknowledged. The authors also thank prof. T. O. Mason and dr. S. Wansom, Department of Materials Science and Engineering, Northwestern University, for their kind availability during the AC-IS investigations.
Keywords
- Fiber dispersion
- Fresh state behavior
- Nondestructive monitoring
- Reinforced concrete
- Self-consolidating fiber
- SFRC post-cracking stiffness
- SFRC toughness
- Steel fiber-reinforced concrete
ASJC Scopus subject areas
- Civil and Structural Engineering
- Building and Construction
- General Materials Science