SLAB BEHAVIOR OF A PRESTRESSED CONCRETE I-BEAM BRIDGE-LEHIGHTON BRIDGE

IN THE TEST PROGRAM, SR-4 STRAIN GAGES WERE ATTACHED TO THE TOP AND BOTTOM SURFACES OF THE DECK SLAB, ALONG A SUPERSTRUCTURE CROSS-SECTION NEAR MIDSPAN. MEASUREMENTS WERE MADE OF THE STRAINS PRODUCED BY THE PASSAGE OF AN HS 20-44 LOAD VEHICLE PASSING ACROSS THE STRUCTURE IN EACH OF NINE LOAD TEST LANES. TESTS WERE CONDUCTED WITH THE VEHICLE MOVING AT SPEEDS RANGING FROM 2 MPH TO 60 MPH, AND MOVING ACROSS A MIDSPAN RAMP AT A SPEED OF 10 MPH. INFORMATION ON STRAINS, STRESSES, AND BENDING MOMENTS IS PRESENTED IN THE FORM OF TABLES AND INFLUENCE LINES. EXPERIMENTAL VALUES OF STRESSES WERE COMPARED WITH THE CORRESPONDING TYPICAL ALLOWABLE STRESSES, AND EXPERIMENTALLY DETERMINED BENDING MOMENTS WERE COMPARED WITH VALUES USED IN THE DESIGN OF THE SLAB. THE EFFECTS OF THE MIDSPAN DIAPHRAGM, THE CORRUGATED STEEL STAY-IN-PLACE FORMS, AND THE LOCAL STRESSES PRODUCED BY THE WHEEL LOADS ARE DISCUSSED. UNDER THE STATIC LOADING OF THE BRIDGE, THE TENSILE AND COMPRESSIVE STRAINS AND STRESSES ON THE CONCRETE SLAB SURFACES WERE SMALL, AND THE EXPERIMENTAL SLAB BENDING MOMENTS WERE CONSIDERABLY LESS THAN THE VALUE USED IN THE DESIGN. UNDER THE IMPACT LOADING, THE MAXIMUM TENSILE STRESS AT ONE GATE LOCATION REACHED THE VICINITY OF THE ULTIMATE TENSILE STRENGTH OF THE CONCRETE. HOWEVER, IT IS CONCLUDED THAT IN GENERAL, THERE IS VERY LITTLE CRACKING OF THE SLAB UNDER TYPICAL LIVE LOAD DESIGN CONDITIONS. /AUTHOR/

• Corporate Authors:

  Lehigh University

  Bethlehem, PA  United States  18015

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Chen, C H
  • VanHorn, D A
• Publication Date: 1971-7

Subject/Index Terms

• TRT Terms: Bending moments; Bridge decks; Bridge superstructures; I beams; Prestressed concrete; Slabs; Strain (Mechanics); Strain gages; Stresses; Wheel loads
• Old TRIS Terms: Strains
• Subject Areas: Bridges and other structures; Highways; Materials;

Filing Info

• Accession Number: 00208021
• Record Type: Publication
• Source Agency: Federal Highway Administration
• Report/Paper Numbers: Study No 67-12
• Files: TRIS, USDOT
• Created Date: Feb 15 1972 12:00AM