Abstract
A simple theoretical approach is used to obtain expressions for the dependence of a number of physical properties of concrete upon the physical properties of its constituents and the aggregate volume concentration. It is assumed that concrete approximates to a two phase material consisting of aggregate particles dispersed in a cement matrix and it is shown that the theory is in reasonable agreement with some Young's modulus, creep and shrinkage measurements made on concrete.
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Abbreviations
- k,k m andk a :
-
bulk moduli of the composite, matrix and aggregate respectively
- k h :
-
bulk modulus of a composite containing pores in place of the aggregate particles
- E, E m and E a :
-
Young's moduli of the composite, matrix and aggregate
- ν, ν m and ν a :
-
Poisson's ratios of the composite, matrix and aggregate
- C, C m and C a :
-
volumetric shrinkages or volumetric thermal contractions of the composite, matrix and aggregate
- C g :
-
volumetric shrinkage of the cement gel
- T, T m and T a :
-
volumetric thermal expansions of the composite, matrix and aggregate
- α, α m and α a :
-
linear coefficients of thermal expansion for the composite, matrix and aggregate
- P:
-
applied hydrostatic stress
- P m :
-
average hydrostatic stress in the matrix
- P a :
-
hydrostatic stress in the aggregate
- ΔP:
-
P a −P m
- σ:
-
applied compressive stress
- σ m :
-
average stress in the matrix
- σ a :
-
average stress in the aggregate
- D a :
-
aggregate volume concentration
- D u :
-
volume concentration of the unhydrated cement in the cement paste
- V m :
-
volumetric strain induced in the matrix by P m
- V a :
-
volumetric strain induced in the aggregate by P m
- dV m :
-
volumetric strain induced in the matrix by an applied hydrostatic stress −ΔP
- dV a :
-
volumetric strain induced in the aggregate by an applied hydrostatic stress ΔP
- dV:
-
average volumetric strain induced in the composite by shrinkage
- t :
-
time
- ε and ε m :
-
average longitudinal strains in the composite and matrix
- ε mt :
-
creep or total strain in a matrix specimen at timet
- a :
-
a constant at a given timet
- τ:
-
change in temperature
References
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Hobbs, D.W. The dependence of the bulk modulus, Young's modulus, creep, shrinkage and thermal expansion of concrete upon aggregate volume concentration. Mat. Constr. 4, 107–114 (1971). https://doi.org/10.1007/BF02473965
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DOI: https://doi.org/10.1007/BF02473965