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Apr 25, 2017
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Jun 1, 2008
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Abstract

Portland cement pastes of various porosities were prepared using water/cement ratios of 0.30, 0.35, 0.40, 0.45, 0.50 and 0.55; and were hydrated for various time intervals ranging from 0.021 to 28 days.  Pore structure and VL–t plots (plots of volume vs. thickness) of the hardened cement pastes were measured using nitrogen gas as the adsorbate. The results were found to be related to the mechanism of hydration as controlled by the pore system of the hardened pastes. Type ІІ adsorption isotherms of nitrogen were obtained for all hardened cement pastes. The adsorption-desorption isotherms indicated the existence of closed hysteresis loops for most of the investigated samples and in some other cases, these isotherms were fully reversible.

 

 

Keywords

Surface area Pore size Portland cement Cement paste Adsorption.

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References

  1. ABO-EL-ENEIN, S.A., ABD-EL-KHALIK, M., HANAFI, S. and EL-HOSINY, F.I. 1985. Surface area and pore structure of polymer-impregnated hardened cement pastes. Zement-Kalk-Gips, 38(11): 675-678.
  2. ABO-EL-ENEIN, S.A., ATA, A.A., HASSANEIN A. and MIKHAIL R.S. 1982. Kinetics and mechanism of slag cement hydration. J. Chem. Tech. Biotech., 32: 939-945.
  3. ABO-EL-ENEIN, S.A., DAIMON, M., OHSAWA, S. and KONDO, R. 1974. Hydration of low porosity slag-lime pastes. Cem. Concr. Res., 4(2): 299-312.
  4. ABO-EL-ENEIN, S.A., HEKAL, E.E., EL-HOSINY, F.I. and ABD-EL-KHALIK, M. 1990. Autoclaved calcium silicate hydrates. 1-rate of formation and molar composition, il Cemento, 87: 147-160.
  5. ABO-EL-ENEIN, S.A., MIKHAIL, R.Sh., DAIMON, M. and KONDO, R. 1978. Surface area and pore structure of hydrothermal reaction products of granulated blast furnace slag. Cem. Concr. Res., 8(2): 151-160.
  6. BABAQI, A.S., BAISSA A.A., SAAD A.M., AL-KADRI F.A., ABO-EL-ENEIN, S.A. 2001. Hydration studies and pore structure on the Portland cement produced in Bajil and Amran, Yemen, Yemeni J. Sci, 2 (2): 21-35.
  7. BRUNAUER, S. and EMMETT, P.H. 1935. The use of van der Waals adsorption isotherms in determining the surface area of iron synthetic ammonia catalysts. J. Amer. Chem. Soc., 57: 1754-1755.
  8. BRUNAUER, S., DEMING, L.S., DEMING, W.E. and TELLER, E. 1940. On a theory of the van der Waals adsorption of gases. J. Am. Chem. Soc., 62: 1723-1732.
  9. BRUNAUER, S., EMMETT, P.H. and TELLER, E. 1938. Adsorption of gases in multimolecular layers. J. Am. Chem. Soc., 60: 309-319.
  10. CRANSTON, R.W. and INKLEY, F.A, 1957. The determination of pore structures from nitrogen adsorption isotherms. Adv. Catalysis, 9: 143-154.
  11. De BOER, J.H., LINSEN, B.G. and OSINGA, Th.J. 1965. Studies on pore systems in catalysts: VI. The universal t curve. J. Catalysis, 4(6): 643-648.
  12. HEKAL, E.E., HANAFI, S., ABO-EL-ENEIN, S.A. and GHORAB, H.Y. 1987. Nitrogen adsorption on low and high porosities alite pastes. TIZ-Tonindustrie-Zeitung (TIZ-Fachberichte), 111(9): 607-611.
  13. LIPPENS, B.C. and De BOER, J.H. 1965. Studies on pore systems in catalysts: V. The t method. J. Catalysis, 4(3): 319-323.
  14. LIPPENS, B.C., LINSEN, B.G. and De BOER, J.H. 1964. Studies on pore systems in catalysts I. The adsorption of nitrogen; apparatus and calculation. J. Catalysis, 3(1): 32-37.
  15. MIKHAIL, R.Sh. and ABO-EL-ENEIN, S.A. 1972. Studies on water and nitrogen adsorption on hardened cement pastes I development of surface in low porosity pastes. Cem. Concr. Res., 2(4): 401-414.
  16. MIKHAIL, R.Sh., ABO-EL-ENEIN, S.A. and ABD-EL-KHALIK, M. 1975. Hardened slag-cement pastes of various porosities. III. Surface area in relation to pore structure. J. Appl. Chem. Biotech., 25(11): 849-857.
  17. MIKHAIL, R.Sh., ABO-EL-ENEIN, S.A., ABD-EL-KHALIK, M. and GABR, N.A. 1978. Autoclaved slag-clinker-sand pastes surface area, pore structure and compressive strength. Cem. Concr. Res., 8(1): 77-85.
  18. MIKHAIL, R.SH., BRUNAUER, S. and BODOR, E.E. 1968. Investigations of a complete pore structure analysis: I. Analysis of micropores. J. Colloid and Inter. Sci., 26(1): 45-53.