DIGEST OF TESTS IN THE UNITED STATES FOR THE DETERMINATION OF THE MODULUS OF ELASTICITY OF PORTLAND CEMENT MORTAR AND CONCRETE

A REVIEW IS PRESENTED OF TESTS DEVELOPED BETWEEN 1895 AND 1899 FOR THE DETERMINATION OF THE MODULUS OF ELASTICITY OF PORTLAND CEMENT MORTAR AND CONCRETE. THIS REVIEW IS FOLLOWED BY YEARLY REVIEWS FROM 1905 THROUGH 1929. COMPRESSION TEST RESULTS ON CONCRETE HAVING TO DO WITH THE EFFECT UPON THE MODULUS OF ELASTICITY OF AGE, RICHNESS OF MIX, REPEATED LOADS, SUSTAINED LOADS AND MOISTURE CONDITIONS ARE PRESENTED. IT IS SHOWN THAT THE MODULUS OF ELASTICITY, UNDER THE CONDITIONS OF THESE TESTS, INCREASES WITH AGE FOR A CONSIDERABLE PERIOD OF TIME. THE INCREASE IN THE MODULUS OF ELASTICITY IS RAPID AT THE EARLY AGES AND ITS RATE DECREASES QUITE UNIFORMLY WITH TIME. AT THE LATER AGES THE MODULI FOR RICH MIXES CONTINUES SUBSTANTIALLY TO INCREASE AFTER THE MODULI FOR THE LEAN MIXES HAVE BECOME PRACTICALLY CONSTANT. THE RICHER THE MIX, OTHER THINGS REMAINING CONSTANT, THE HIGHER THE MODULUS OF ELASTICITY. THE MODULUS OF ELASTICITY OF A GIVEN CONCRETE WHEN THE PORE SPACES ARE FILLED WITH WATER, IS MATERIALLY GREATER THAN FOR THE SAME CONCRETE WHEN AIR DRY. WHILE THE EFFECT OF FREE MOISTURE WITHIN THE MASS IS TO DECREASE THE COMPRESSIVE STRENGTH, THE MODULUS OF ELASTICITY IS THEREBY INCREASED. THE SUSTAINED MODULUS AFTER A PROLONGED PERIOD OF SUSTAINED STRESS IS BUT A FRACTION OF THE INSTANTANEOUS MODULUS AND THIS FRACTION IS GREATER FOR HIGH STRESSES THAN FOR LOW ONES. THE SUSTAINED MODULUS OF ELASTICITY IS SUBSTANTIALLY HIGHER FOR A WET CONCRETE THAN FOR THE SAME CONCRETE WHEN AIR DRIED. THE EFFECT OF A LOAD APPLIED AT AN EARLIER AGE IS TO INCREASE THE MODULUS OF ELASTICITY WHEN THE SAME LOAD IS APPLIED AT A LATER AGE.

  • Supplemental Notes:
    • Vol 30, ParT 1, PP 635-660, 21 TAB
  • Authors:
    • Teller, L W
  • Publication Date: 1930

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00212654
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jul 8 1994 12:00AM