Page 17 - Concrete-Technology-Interacted_Book_Prof-MIK_Neat

PART 3

Properties of hardened
concrete

Strength and failure of
concrete under short-

term, cyclic and
sustained loading

6.1 Deformation, fracture and failure
6.1.1 The structure of concrete

Concrete is a multiphase material containing cement paste (unhydrated and hydrated
compounds), fluids, aggregates, discontinuities, etc. The overall mechanical and physical
properties of such a composite system depend on the volume fractions and properties of
the various constituents and the mechanisms of interaction, whether mechanical, physical
or chemical, between the separate phases.

6.1.2 Stresses and strains

At a location in an element of material the generalized stress (strain) state in one, two or
three dimensions comprising direct and shear stresses (strains) can be decomposed
geometrically to a system of mutually perpendicular principal stresses (strains) σ1, σ2, σ3

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