Effective Slab Width Definition for Negative Moment Regions of Composite Bridges

Currently, the American Association of State Highway and Transportation Officials-Load Resistance Factor Design (AASHTO-LRFD) design code specifies the same effective slab width design criteria for both positive moment sections and negative moment sections. The only difference in computing effective slab width between the positive and negative moment regions is the value of effective span length (L sub e), the definition of which is problematic. The effective slab width concept for the positive moment regions has been investigated by many researchers. However, the classical effective slab width definition does not take into account both the strain variation through the slab thickness and the mechanism that redistributes load from concrete to steel reinforcement after cracking. In this paper, a more robust effective slab width definition for the negative moment section is introduced to account for these factors. The proposed definition is developed for negative moment regions and explored by using the finite-element method (FEM). The finite-element modeling scheme is briefly discussed, and the model is successfully verified with experimental results. Numerical results show the simplicity, accuracy, and robustness of the proposed definition in extracting effective slab width values from FEM results. Numerical results also indicate that the effective slab width criteria in the current AASHTO-LRFD Specifications is typically conservative for larger girder spacings. Detailed calculations of effective slab width for the negative moment regions using the proposed definition are summarized at the end of this paper.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/oclc/32947845
• Authors:
  • Aref, Amjad J
  • Chiewanichakorn, Methee
  • Chen, Stuart S
  • Ahn, Il-Sang
• Publication Date: 2007-5

Language

• English

Media Info

• Media Type: Print
• Features: Appendices; Figures; References; Tables;
• Pagination: pp 339-349
• Serial:
  • Journal of Bridge Engineering
  • Volume: 12
  • Issue Number: 3
  • Publisher: American Society of Civil Engineers
  • ISSN: 1084-0702
  • Serial URL: http://ojps.aip.org/beo

Subject/Index Terms

• TRT Terms: Bridge design; Finite element method; Girders; Material reinforcement; Slabs; Width
• Uncontrolled Terms: Bridge spans; Composite bridges; Negative moment regions
• Subject Areas: Bridges and other structures; Design; Highways; I24: Design of Bridges and Retaining Walls;

Filing Info

• Accession Number: 01051532
• Record Type: Publication
• Files: TRIS
• Created Date: Jun 14 2007 6:14PM