Porosity, pore size distribution and in situ strength of concrete

In this study, in situ strength of concrete was determined through compression test of cores drilled out from laboratory cast beams. The apparent porosity and pore size distribution of the same concrete were determined through mercury intrusion porosimetry, performed on small-drilled cores. The normal-strength concrete mixes used in the experimental investigation were designed to exhibit a wide variation in their strengths. To ensure further variation in porosity, pore size distribution and strength, two modes of compaction, two varieties of coarse aggregates, different levels of age, curing period and exposure condition of concrete were also introduced in experimental scheme. With the data so generated, an appraisal of the most frequently referred relationships involving strength, porosity and pore size of cement-based materials was carried out. Finally, a new empirical model relating the in situ strength of concrete with porosity, pore size characteristics, cement content, aggregate type, exposure conditions, etc., is presented.

[1]  R. K. Lewis.  THE COMPRESSIVE STRENGTH OF CONCRETE CORES , 1972 .

[2]  A. M. Brandt.  Cement-based Composites: Materials, Mechanical Properties and Performance , 1995 .

[3]  D. Hannant.  4.11 – Cement-based Composites , 2000 .

[4]  Sidney Diamond,et al.  Mercury porosimetry: An inappropriate method for the measurement of pore size distributions in cement-based materials , 2000 .

[5]  T. S. Nagaraj,et al.  Generalization of Abrams' law , 1996 .

[6]  Rakesh Kumar,et al.  Some aspects of evaluation of concrete through mercury intrusion porosimetry , 1997 .

[7]  U. Ludwig,et al.  Determination of permeable porosity , 1973 .

[8]  E. J. Sellevold.  Mercury porosimetry of hardened cement paste cured or stored at 97°C , 1974 .

[9]  P. K. Mehta.  Concrete: Structure, Properties, and Materials , 1992 .

[10]  E. J. Sellevold,et al.  Mercury porosimetry of hardened cement paste: the influence of particle size , 1975 .

[11]  Bkr Prasad,et al.  Fracture Mechanics of Concrete , 2002 .

[12]  I. Soroka.  Portland cement paste and concrete , 1979 .

[13]  D. Winslow,et al.  The pore structure of paste in concrete , 1990 .

[14]  T. Luping.  A study of the quantitative relationship between strength and pore-size distribution of porous materials , 1986 .

[15]  S. Diamond,et al.  A MERCURY POROSIMETRY STUDY OF THE POROSITY IN PORTLAND CEMENT , 1970 .

[16]  F. S. Rostásy,et al.  Changes of pore structure of cement mortars due to temperature , 1980 .

[17]  D. Hasselman.  Relation Between Effects of Porosity on Strength and on Young's Modulus of Elasticity of Polycrystalline Materials , 1963 .

[18]  Rakesh Kumar,et al.  STUDY ON SOME FACTORS AFFECTING THE RESULTS IN THE USE OF MIP METHOD IN CONCRETE RESEARCH , 2003 .

[19]  I. Odler,et al.  Investigations on the relationship between porosity, structure and strength of hydrated Portland cement pastes. II. Effect of pore structure and of degree of hydration , 1985 .

[20]  S. Diamond.  A critical comparison of mercury porosimetry and capillary condensation pore size distributions of portland cement pastes , 1971 .

[21]  S. Popovics.  New Formulas for the Prediction of the Effect of Porosity on Concrete Strength , 1985 .

[22]  T. Hansen,et al.  CEMENT PASTE AND CONCRETE , 1973 .