Many people are interested in how various power effects and loads affect concrete structures. Concrete is a solid body with a tendency to succumb to deformation when exposed to external forces. It is the ability to elastic deformation (temporary) reflects the modulus of elasticity of concrete.
The value of elasticity is determined when testing various samples for resistance to tension or compression. However, you should know that concrete that does not contain reinforcement is unstable to stretching. Based on the test results, a graph is constructed of the dependence of the occurring deformations on the forces applied to the material. Visibility contributes to a better understanding. It is also necessary to know the initial modulus of elasticity of concrete and the amount of deformation.
Under load, an increase in deformation is due to the fact that concrete has the property of creep. First, at a certain pressure, elastic deformation occurs in it. It is a phenomenon in which a body that is deformed from a load returns to its original shape after its disappearance. Then, upon further loading, irreversible (plastic) deformations begin to occur in the material. However, it is extremely difficult to separate the plastic and elastic changes. Because an instant change in shape depends on the rate of increase in load. Because of this, deformation during an increase in load is called elastic, and a further increase in shape change is called plastic. It is due to the creep of concrete. Further deformation is already the destruction of the object. This modulus of elasticity of concrete is often also called the deformation modulus. It is determined using different methods.
The initial elastic modulus of concrete is very difficult to determine. However, its approximate value can be established indirectly. On many graphs, the secant line to the curve reflecting the dependence of stress on deformation very often, although not always, happens to be parallel to the tangent, which goes through the origin.
The assertion that the modulus of elasticity of concrete increases in direct proportion to the root of its strength will be relatively true. However, this is true only for the main part on the graph (stress-strain) and depends on the environment and test conditions. As an example, water-saturated types of material in tests have a higher modulus of elasticity than dry samples. Although their strength properties are similar.
The modulus of elasticity is strongly influenced by the qualities of the coarse filler. This relationship is straightforward. Naturally, the rate of lightweight concrete will be lower than that of heavy samples. Elasticity also increases with the age of the materials. For example, the elastic modulus of concrete is B25, in one year it will be higher than initially, and in 10 years it will increase even more. To determine the elasticity indicators, there is a special table where approximate initial modules of the material of each grade are indicated.