DAMPING CAPACITY OF HARDENED CEMENT PASTE AND MORTAR IN SPECIMENS VIBRATING AT VERY LOW FREQUENCIES

THE DAMPING CAPACITIES OF CEMENT PASTE AND MORTAR SPECIMENS VIBRATING AT FREQUENCIES FROM 0.16 TO 4 CPS AND WITH STRAIN AMPLITUDES UP TO 150 X 10 TO THE MINUS 6 POWER WERE MEASURED. THE ENDS OF THE SPECIMEN WERE CLAMPED TO THE MIDPOINTS OF METAL BEAMS. THE APPARATUS WAS SUSPENDED FROM A RIGID BEAM BY WIRES CONNECTED TO THE CENTERS OF GRAVITY OF THE INERTIAL BEAMS. THE SPECIMENS WERE VIBRATED BY DRAWING ADJACENT ENDS OF THE INERTIAL BEAMS TOWARD EACH OTHER AND RELEASING THEM. THE RELATIVE POSITION OF THE ENDS OF THE INERTIAL BEAMS WERE SENSED BY A NONCONTACTING ELECTRONIC PICKUP, AND THE LOGARITHMIC DECREMENT WAS MEASURED DIRECTLY USING AN OSCILLOSCOPE AND CAMERA. THE LOGARITHMIC DECREMENT INCREASED LINEARLY WITH STRAIN AMPLITUDE OVER THE RANGE OF STRAINS INVESTIGATED. AT FREQUENCIES BELOW 2.5 CPS THE LOGARITHMIC DECREMENT INCREASED WITH DECREASING FREQUENCY. THE AUTHORS SUGGEST THE PROCESSES RESPONSIBLE FOR THE LOW- FREQUENCY DAMPING EFFECTS ARE THE SAME ONES THAT GOVERN CREEP. /AUTHOR/

  • Supplemental Notes:
    • Vol 65, pp 661-667
  • Authors:
    • Cole, D G
    • SPOONER, D C
  • Publication Date: 1965

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  • Accession Number: 00212527
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jan 16 1994 12:00AM