so many people are interested in the effect on concrete structures and the impact of various power loads.Concrete is a solid body having a tendency to resist deformation when exposed to external forces.It is capable of elastic deformation (temporary nature) reflects the elastic modulus of concrete.
The amount of elasticity is determined at testing different samples for resistance to tension or compression.However, it is known that the concrete which contains no reinforcement stretchability unstable.Based on the test results plotted deformations arising from forces applied to the material.Visibility of a better understanding.It is also necessary to know the initial modulus of elasticity of concrete and the magnitude of the deformation.
increase in deformation under load due to the fact that the concrete has this property, as creep.First, at a certain pressure in the elastic deformation occurs.It is a phenomenon in which the body is deformed by stress, it returns to its original shape after her disappearance.Then, with further stress in the material begin to occur irreversible (plastic) deformation.However, divide plastic and elastic change extremely difficult.Because the instantaneous change in the shape depends on the rate of load increase.Due to this deformation during the load increase is called elastic, and further increase the change of shape - plastic.It is due to concrete creep.Further strain is already destroying the object.This modulus of elasticity of concrete is often also called the modulus of deformation.It is determined using different techniques.
initial modulus of elasticity of concrete is determined very difficult.However, its approximate value can be set indirectly.Many charts secant line to the curve, reflecting the stress-strain, very often, though not always, parallel to the tangent, which goes through the origin.
relatively true to say that the modulus of elasticity of concrete increases in direct proportion to the root of his strength.However, this is true only for the main part of the graph (stress-strain) and depends on the environment and the test conditions.As an example, the types of water-saturated material tests have greater modulus index than dry samples.While strength properties are similar.
on the modulus of elasticity greatly affect the quality of a large vehicle.This dependence is rectilinear.Naturally, that the exponent of lightweight concrete will be lower than heavy samples.The resiliency is also increased with increasing age of materials.For example, the modulus of elasticity of concrete B25, one year is higher than initially, and after 10 years it will increase even more.To determine the parameters of elasticity there is a special table, which shows the approximate initial modulus of the material of each brand.
