What is FCK concrete?
The characteristic strength (fck) is the value in the x-axis below which 5% of the total area under the curve falls. So we can say the given concrete mix has a characteristic strength of 30 MPa or it is a M30 grade mix.
Which of the following material is more elastic?
Which is more elastic solid liquid or gas?
As compressibility of liquids and gases is more than solids the bulk modulus is reciprocal of compressibility. Therefore solids are more elastic than liquid and gases.
What is secant modulus of elasticity of concrete?
Secant modulus is one of several methods used to calculate modulus of elasticity, which is a measurement of a material’s elasticity. Calculating secant modulus involves using two points on a stress-strain curve to calculate the slope of the stress/strain.
What is negative Poisson’s ratio?
Auxetics are structures or materials that have a negative Poisson’s ratio. When stretched, they become thicker perpendicular to the applied force. This occurs due to their particular internal structure and the way this deforms when the sample is uniaxially loaded.
Which is more elastic iron or rubber?
Since, the iron rod regains its original configuration more efficiently than rubber, it is iron which is more elastic than rubber. However, the iron rod is less plastic because it shows more tendency to return to its original configuration after the deforming forces are removed.
How is the modulus of elasticity of concrete measured?
Elastic modulus of concrete is directly measured by the static uniaxial compressive test in accordance with ASTM C469 , which is called static elastic modulus. Elastic modulus of concrete can be determined by dynamic test methods such as ultrasonic pulse velocity and resonance frequency tests .
What is meant by Poisson’s ratio?
Poisson’s ratio is defined as the ratio of the change in the width per unit width of a material, to the change in its length per unit length, as a result of strain.
What are the examples of elastic materials?
The materials that can be stretched and when released attains their original shape and size are known as elastic materials. Rubber band is an example of elastic material.
What are the factors affecting modulus of elasticity of concrete?
8 Factors Affecting Modulus of Elasticity of Concrete
- Strength of Concrete.
- Cement Paste.
- Concrete Wetness Condition.
- Transition Zone.
- Mix Proportion.
- Concrete Age.
- Curing Regime.
How do you find Poisson’s ratio?
The equation for calculating Poisson’s ratio is given as ν=(-ε_trans)/ε_axial. Transverse strain (ε_trans) is measured in the direction perpendicular to the applied force, and axial strain (ε_axial) is measured in the direction of the applied force.
What is the SI unit of elasticity?
What are the 4 types of elasticity?
Four types of elasticity are demand elasticity, income elasticity, cross elasticity, and price elasticity.
Why is elastic modulus important for concrete?
The higher the value of the modulus, the stiffer the material is. Thus, comparing a high performance concrete to a normal strength concrete, it is seen that the elastic modulus for high performance concrete will be higher, thereby making it a stiffer type of concrete.
Why steal is more elastic than rubber?
By this definition, steel is more elastic than rubber because steel comes back to its original shape faster than rubber when the deforming forces are removed. For a given stress (stretching force per unit area) strain is much smaller in steel than in rubber and hence the answer.
Which one has maximum elastic limit?
Can Poisson’s ratio be greater than 1?
Poisson’s ratios exceeding 1/2 are permissible in an- isotropic materials. Indeed, hexagonal honeycombs can exhibit Poisson’s ratio of 1, and if they have oriented hexagonal cells, greater than 1, in certain directions .
What are the 4 main properties of concrete?
The properties of hardened concrete
- Mechanical strength, in particular compressive strength. The strength of normal concrete varies between 25 and 40 MPa.
- Porosity and density.
- Fire resistance.
- Thermal and acoustic insulation properties.
- Impact resistance.
Is Poisson’s ratio positive or negative?
One of the important mechanical properties of materials is Poisson’s ratio, which is positive for most of the materials. However, certain materials exhibit “auxetic” properties; that is, they have a negative Poisson’s ratio. Thus auxetic and non-auxetic materials exhibit different deformation mechanisms.
What is Poisson’s ratio for concrete?
between 0.20 to 0.25
What is Young’s modulus and Poisson’s ratio?
Poisson’s ratio is related to elastic moduli K (also called B), the bulk modulus; G as the shear modulus; and E, Young’s modulus, by the following (for isotropic solids, those for which properties are independent of direction). The elastic moduli are measures of stiffness. They are ratios of stress to strain.
What is dynamic modulus of elasticity of concrete?
Dynamic Modulus: The value of modulus of elasticity Ec determined by actual loading of concrete is known as static modulus of elasticity. The modulus of elasticity is determined by subjecting the specimen to longitudinal vibration at their natural frequency that is why this is known as dynamic modulus.
What is the value of modulus of elasticity of concrete?
The elastic modulus of the hardened paste may be in the order of 10-30 GPa and aggregates about 45 to 85 GPa. The concrete composite is then in the range of 30 to 50 GPa.
Which is more elastic steel or plastic?
Answer. By definition steel is more elastic than plastic because it regain its original shape faster than rubber after removal of deforming force.
Why is Poisson’s ratio important?
Poisson’s ratio is a useful measure of how much a material deforms under stress (stretching or compression). It is important for mechanical engineering as it allows materials to be chosen that suit the desired function.
Which cement has highest compressive strength?
Taiheiyou Cement Corporation of Japan has recently developed a new cementitious material that is claimed to deliver record compressive strength of 464 N/mm2 using normal pour-and-form techniques.
Why glass is more elastic than rubber?
(a) Glass is more elastic than rubber because for a given applied force per unit area, the strain produced in glass is much smaller than the strain produced in rubber.
Is concrete elastic or plastic?
Is Concrete Really Elastic? In a word, yes. But the elasticity is a way to characterize the mechanical response of the material body for applied stresses that stay within the linear regime.
Is Young’s modulus a material property?
The Young’s Modulus of a material is a fundamental property of every material that cannot be changed. It is dependent upon temperature and pressure however. The Young’s Modulus (or Elastic Modulus) is in essence the stiffness of a material. In other words, it is how easily it is bended or stretched.
What is Poisson’s ratio in strength of materials?
Poisson’s Ratio: It is defined as the ratio of lateral strain to the longitudinal strain within elastic limit. It means that when a material is loaded within elastic limit than the ratio of lateral strain to the longitudinal strain gives us a constant called poisson’s ratio.