SOME ANALYTICAL ASPECTS OF FRESH CONCRETE

THE FLOCCULENT STATE OF FRESH CEMENT PASTE ACCOUNTS FOR THE PLASTICITY OF FRESH CONCRETE. CEMENT PASTE AND CONCRETE CAN EXIST IN TWO DIFFERENT RHEOLOGICAL STATES' THE PLASTIC STATE AND THE FLUIDIZED STATE. IN THE FLUIDIZED STATE, PASTE AND CONCRETE BEHAVE AS VISCOUS BUT NON- NEWTONIAN FLUIDS. THE FLUIDIZED STATE CAN BE MAINTAINED BY VIBRATION, OR BY RAPID CONTINUOUS SHEARING UNDER THE FEW CONDITIONS WHERE THAT IS POSSIBLE. THE CONSISTENCY OF PASTE OR CONCRETE IN THE FLUIDIZED STATE CAN BE EXPRESSED IN TERMS OF ITS COEFFICIENT OF PLASTIC VISCOSITY, IN THE PLASTIC STATE IT CAN BE EXPRESSED IN TERMS OF THE MODULUS OF STIFFNESS. EITHER VISCOSITY OR STIFFNESS IS AN EXPONENTIAL FUNCTION OF THE RATIO OF SOLID MATERIAL TO WATER IN THE MIXTURE. FIGURES OBTAINED FROM THE SLUMP TEST, REMOULDING TEST AND OTHER EMPIRICAL TESTS FOR CONSISTENCY FOLLOW THE SAME LAW. THE WATER-REQUIREMENT FACTOR OF THE CEMENT, PLUS THE PRODUCT OF THE WATER- REQUIREMENT OF THE AGGREGATE AND THE AGGREGATE CEMENT RATIO, GIVES THE TOTAL WATER-REQUIREMENT FACTOR. GRAPHICAL ANALYSIS SHOWS THAT THE OPTIMUM MIXTURE HAS THE LOWEST VOID CONTENT /WATER PLUS AIR/. IT IS SUGGESTED THAT THIS ANALYTICAL PROCEDURE BE USED TO PRODUCE OPTIMIZED CONCRETE WITH RESPECT TO ALL PERTINENT PROPERTIES.

  • Supplemental Notes:
    • Vol41, No2, PP29-36, VOL41, NO3, PP67-73, 22FIG, 4TAB, 16REF
  • Authors:
    • Powers, T C
  • Publication Date: 1966-2

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  • Accession Number: 00212226
  • Record Type: Publication
  • Source Agency: Road Research Laboratory /UK
  • Files: TRIS
  • Created Date: Jul 29 2004 5:28PM