Properties of Cement Concrete in Plastic & Hardness Stage
Properties of Cement Concrete
In this article, we discuss various properties of cement concrete in the plastic stage and hardness stage
Properties of Cement Concrete in Plastic Stage
Fresh concrete shows the property of mixability wherein all the concrete constituents are so mixed so as to produce a homogeneous mix.
In fresh concrete, if water is in excess then this water comes out to the surface of concrete known as bleeding.
It is the most important property of fresh concrete which defines the ease with which concrete can be placed and compacted.
Fresh concrete should give a smooth surface finish without any honeycombing.
Properties of Concrete in Hardened State
It is the most important property of hardened concrete which is assessed either by cube test or cylinder test.
The compressive strength given by different samples of the same concrete may give different results.
Since it is difficult to carry out direct tensile strength test on concrete and thus tensile strength of concrete at failures is called as modulus of rupture of concrete.
Modulus of Elasticity
It is the ratio of direct stress to strain but for concrete, different modulus of elasticity of concrete is defined viz. initial tangent modulus, secant modulus and tangent modulus.
For concrete, Poisson's ratio defines compression as the ratio of lateral strain to the longitudinal strain. For concrete, the Poisson's ratio varies from 0.1 to 0.21.
It is the increase in the strain of concrete with time due to sustained loading. Rate of creep decrease with time.