THE AASHO ROAD TEST: REPORT 4 - BRIDGE RESEARCH
A COMPREHENSIVE DESCRIPTION IS PRESENTED OF ALL RESEARCH RELATED TO BRIDGE STRUCTURES IN THE AASHO ROAD TEST. THE OJECTIVES, SCOPE AND BACKGROUND OF THE RESEARCH AND THE ORGANIZATION NECESSARY TO CARRY OUT THE RESEARCH ARE DESCRIBED. THE TEST STUCTURES AND THE EXPERIMENTS CONDUCTED ARE DESCRIBED. RESULTS ARE PRESENTED OF TESTS WITH REPEATED STRESSES AND DYNAMIC LOAD TESTS. SUPPLEMENTARY TESTS AND STUDIES ARE DISCUSSED. THE TESTS OF THE BRIDGES AT THE AASHO ROAD TEST FURNISHED AN OVERALL DESCRIPTION OF THE BEHAVIOR OF BEAM AND SLAB BRIDGES UNDER REPEATED HIGH STRESSES AND AN INSIGHT INTO THE PROBLEM OF THE DYNAMIC EFFECTS OF MOVING VEHICLES ON THE RESPONSE OF BRIDGES. THE FOLLOWING SPECIFIC FINDINGS ARE SUMMARIZED: (1) FATIGUE CRACKING IN VARYING AMOUNTS OCCURRED IN ALL FIVE STEEL BRIDGES WITH PARTIAL- LENGTH OVER-PLATES, WELDED TO THE TENSION FLANGES OF THE ROAD SECTIONS, AFTER THEY WERE SUBJECTED TO BETWEEN 477,900 AND 536,000 TRIPS OF TEST VEHICLES, (2) FATIGUE FAILURES OF REINFORCING BARS OCCURRED IN BOTH REINFORCED CONCRETE BRIDGES IN WHICH THE MEAN STRESS RANGE WAS 26 KSI AND THE MINIMUM STRESS WAS 19 KSI, (3) FATIGUE DISTRESS WAS OBSERVED IN THE BEAMS WITH PARTIAL-LENGTH COVERPLATES OF THE STEEL BRIDGES AND IN THE REINFORCING BARS OF THE REINFORCED BRIDGES OCCURRED IN THE SAME MANNER AS THAT OBSERVED IN LABORATORY TESTS, (4) THE STEEL BRIDGE WITHOUT COVERPLATES SUBJECTED TO 392,400 TRIPS OF TEST VEHICLES WITHSTOOD THE REPEATED STRESSING WITHOUT FATIGUE CRACKING, (5) IN THE MOST HIGHLY STRESSED PRESTRESSED CONCRETE BRIDGE, THE PRESTRESSING STEEL WITHSTOOD 556,700 CYCLES OF STRESS WITHOUT FAILURE, (6) FATIGUE CRACKING OF CONCRETE WAS DETECTED IN PRESTRESSED CONRETE BEAMS SUBJECTED TO TENSILE STRESSES LOWER THAN THE MODULUS OF RUPTURE OF CONCRETE, (7) THE BEHAVIOR OF COMPOSITE STEEL BRIDGES WAS CLEARLY SUPERIOR TO THAT OF THE NON-COMPOSITE STEEL BRIDGES, (8) THERE WAS A MARKED DIFFERENCE BETWEEN THE CRACKING OF THE PRESTRESSED CONCRETE BEAMS POST-TENSIONED WITH PARALLEL WIRE CABLES AND THOSE PRETENSIONED WITH 7-WIRE STRANDS, (9) THE PATTERN OF TENSION CRACKING OF REINFORCED BEAMS WAS SUBSTANTIALLY DIFFERENT IN THE BRIDGES WITH REINFORCEMENT STRESSED TO ABOUT 33,000 PSI AND IN THOSE WITH REINFORCEMENT STRESSED TO ABOUT 42,000 PSI, (10) THE RESULTS OF THE DYNAMIC TESTS ON THE BRIDGES WERE FOUND TO BE IN SATISFACTORY AGREEMENT WITH THOSE OBTAINED FROM THE THEORY USED IN THE STUDY, (11) BECAUSE OF THE SPECIAL CONDITIONS OF THE BRIDGE TESTS, THE RELATIVE MAGNITUDES OF THE DYNAMIC EFFECTS FOR THE DIFFERENT BRIDGE TYPES ARE NOT INDICATIVE OF THOSE WHICH WOULD BE OBTAINED UNDER MORE TYPICAL CONDITIONS, AND (12) THE OBSERVED DEFECTS OF THE IRREGULARITIES IN THE BRIDGE DECKS AND IN THE APPROACH PAVEMENTS REEMPHASIZE THE IMPORTANCE OF SMOOTH DECK AND PAVEMENT SURFACES.
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Supplemental Notes:
- Part D, 229 PP, 129 FIG, 84 TAB, 41 PHOT, 5 APP Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved
- Publication Date: 1962
Media Info
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Serial:
- Highway Research Board Special Report
- Issue Number: 61D
- Publisher: Highway Research Board
Subject/Index Terms
- TRT Terms: Accelerated tests; Bridge approaches; Bridge construction; Bridge decks; Bridge foundations; Bridge members; Bridges; Composite structures; Construction; Dynamic loads; Dynamic tests; Failure; Fatigue (Physiological condition); Fracture mechanics; Highway bridges; Material reinforcement; Metal bridges; Motion; Motor vehicles; Posttensioning; Prestressed concrete; Repeated loads; Slabs; Steel bridges; Stresses; Structural plates
- Identifier Terms: AASHO Road Test
- Uncontrolled Terms: Moving vehicles; Plates
- Old TRIS Terms: Cover
- Subject Areas: Bridges and other structures; Construction; Highways;
Filing Info
- Accession Number: 00209033
- Record Type: Publication
- Files: TRIS, TRB
- Created Date: Sep 15 1994 12:00AM