ANALYSIS OF METHODS OF COMPRESSION-DEFLECTION TESTING OF PREFORMED ELASTOMERIC COMPRESSION SEALS

THIS PAPER IS A STUDY OF SOME OF THE WAYS IN WHICH COMPRESSION-DEFLECTION TESTS VARY; SPECIFICALLY, THE NUMBER OF COMPRESSION CYCLES THAT MUST BE RUN AND THE EFFECT OF VARYING TOTAL DEFLECTION AND CROSSHEAD SPEEDS WERE STUDIED. THE STUDY SHOWS THAT 3 COMPRESSION-DEFLECTION CYCLES MUST BE RUN BEFORE THE FORCE-DEFLECTION CURVE PRODUCED APPROXIMATES THE EQUILIBRIUM FORCE-DEFLECTION CURVES. IF FEWER CYCLES ARE RUN, THE RESULTS CANNOT BE CONSIDERED EQUAL TO THE EQUILIBRIUM VALUES AND HENCE CHARACTERISTIC OF THE SEAL'S TRUE PERFORMANCE IN SERVICE. THE STUDY ALSO POINTED TO 2 SOURCES OF VARIANCE IN THE TEST RESULTS. THE FIRST SOURCE WAS CHANGING LOADS; AS THE LOADS OR TOTAL DEFLECTION CHANGES, VALUES ON THE FORCE-DEFLECTION CURVES ALSO CHANGE. THE RESULT IS THAT, IF 2 DIFFERENT LOADS ARE CHOSEN TO TEST IDENTICAL SEALS, VALUES COMMON TO BOTH FORCE-DEFLECTION CURVES PRODUCED WILL NOT BE EQUAL. THE SECOND SOURCE WAS CROSSHEAD SPEEDS. THOUGH THE SPEED VARIANCE WAS NOT SO GREAT AS THE VARIANCE CAUSED BY CHANGING LOADS, IT GENERALLY, FOR THE SPEEDS TESTED, PRODUCED RESULTS THAT WERE NOT EQUAL. THE RESULTS AND ACCOMPANYING CONCLUSIONS SHOW HOW THOSE FACTORS AFFECTED THE TESTS AND SUGGEST POSSIBLE SOLUTIONS TO THE PROBLEM.

Media Info

  • Media Type: Print
  • Features: Figures; References; Tables;
  • Pagination: pp 11-24
  • Monograph Title: Materials for pavement marking and for joints in concrete structures
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00217353
  • Record Type: Publication
  • ISBN: 0309021782
  • Files: TRIS, TRB
  • Created Date: Jan 11 1974 12:00AM