STEEL, CONCRETE, ALUMINUM, AND TIMBER IN SYSTEMS BRIDGES

TWO MAJOR REQUIREMENTS OF TOMORROW'S BRIDGES ARE ECONOMY AND AESTHETICS. EACH OF THE FOUR MATERIALS CONSIDERED HERE IS ECONOMICALLY COMPETITIVE IN SOME SITUATIONS AND NOT IN OTHERS, AND EACH HAS ITS OWN AESTHETIC USES AND LIMITATIONS. FUTURE CONCRETE USE INCLUDES ADJUSTABLE, NUMERICALLY CONTROLLED FORMS IN BOTH PRECAST AND SLIPFORM APPLICATION. STRENGTHS UP TO 10,000 PSI SHOULD BECOME COMMONPLACE, ESPECIALLY IN PRESENT APPLICATIONS. NEW CEMENTS AND IMPROVED METHODS OF ACCELERATING CURING WILL PRODUCE GREATER ECONOMY IN PRECAST OPERATIONS. USE OF SEL-STRESSING CEMENTS SEEMS MORE PROMISING THAN EVER BEFORE. LIGHTWEIGHT AGGREGATE PROMISES TO GAIN IN ACCEPTANCE. STEELS WILL UNDERGO STILL FURTHER INCREASES IN STRENGTH, AND NUMERICALLY CONTROLLED FABRICATION PROMISES TO IMPROVE NOT ONLY SPEED BUT ECONOMY AND PRECISION AS WELL. THIS WILL BE BENEFICIAL TO COMPLEX CONFIGURATIONS AS WELL AS TO REPETITIVE STANDARD UNITS. WHILE ALUMINUM'S GREAT ADVANTAGE IS ITS LIGHT WEIGHT AND FLEXIBILITY OF FABRICATION, IT SUFFERS FROM A RELATIVELY HIGH FIRST COST. ONCE THIS IS REDUCED, ALUMINUM WILL BECOME COMPETITIVE IN A BROADER RANGE OF APPLICATIONS. PROBABLY THE GREATEST FURTURE DEVELOPMENT IN WOOD WILL BE IN EDUCATING ENGINEERS REGARDING THE CAPABILITY OF GLUED AND LAMINATED STRUCTURAL TIMBERS FOR BRIDGE CONSTRUCTION.

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Filing Info

  • Accession Number: 00215594
  • Record Type: Publication
  • ISBN: 0309020638
  • Files: TRIS, TRB, ATRI
  • Created Date: Apr 2 1973 12:00AM