In other words, it reflects the ability of concrete to deflect elastically. Among these, the secant modulus at a stress of about cube strength of. Masonry in poor condition is given a strength equal to onethird of that for masonry in good condition, to reflect the influence of mortar deterioration and unit cracking on compressive strength. Youngs modulus modulus of elasticity, e yield strength, f y. An empirical formula was derived for the actual elastic modulus of concrete, which is recommended for computing prestress losses, deflections, and other displacements of concrete structures. In pretensioned concrete, the four major sources of prestress losses are elastic shortening. The modulus of elasticity of a concrete is controlled by the moduli of elasticity of its components. Surface repairs must be dimensionally and mechanically compatible with the existing concrete substrate to minimize cracking and ensure that the repair. Aci structural journal technical paper a practical. Relationship between compressive strength and modulus of. It is a fundamental parameter needed for evaluating the deformations and the intrinsic frequencies needed. Modulus of elasticity of concrete determination and importance in. Detailed instructions for operating the fx 250t and fx500 test machines are provided in appendices. The influence of concrete composition on youngs modulus core.
The estimation of the elastic modulus of concrete using nondestructive methods requires the application of a relationship between the dynamic and static elastic modulus as well as a relationship between the static elastic modulus and compressive strength of concrete. Modulus of elasticity of concreteec is defined as the ratio of the. We can have different modulus as shown in the figure below. The modulus of elasticity is a property of concrete, which is directly dependent on its formula. The primary objective of this study is to investigate the effects of cylinder size 150 by 300 mm and 100 by 200 mm on empirical equations that relate static elastic moduli and compressive strength and static and dynamic elastic moduli of concrete. Ecmt fcmtfcm0,3e cm tangent modulus, ec, may be taken as 1. A practical equation for elastic modulus of concrete. Pdf many empirical equations for predicting the modulus of elasticity as a function of compressive strength can be found in the current. The linear analysis of elements, which is based on elastic theory, is used in some cases to satisfy requirements of ultimate and serviceability limit state such as in the design of prestressed concrete structures. Youngs modulus tensile and yield strength for common. One approach for estimating the original elastic modulus i. As a consequence, such models can only be used to evaluate the effects produced by the concrete components on the modulus of elasticity.
However, for frc with cs smaller than 1 and fiberreinforced cement composites frccs, discrete fibers reduced the elastic modulus. Elastic modulus is a fundamental parameter in designing concrete structures. Modulus of elasticity of concrete the modulus of elasticity of concrete e c adopted in modi. Elasticity modulus, shrinkage, and creep of highstrength. Approximate values for the modulus of elasticity e cm, secant value between. Elastic modulus of lightweight concrete with pvc aggregate was studied by kou et al. Tilt the spherically seated block so that the bearing face is parallel to the top surface of the sample. The value of elastic modulus of concrete can be obtained using formulas provided by different codes, but the values may not be accurate. Approximate values for the modulus of elasticity e cm secant value between. The stiffness of the structure is directly related to the stiffness of the concrete, which is a function of its elastic moduli. Youngs modulus tensile and yield strength for common materials. The modulus of elasticity of concrete is relatively constant at low stress levels but starts decreasing at higher stress levels as matrix cracking develops. Losses due to anchorage set, friction and elastic shortening are instantaneous.
It has high compressive strength and low tensile strength. Concrete modulus of elasticity with example youtube. Jan 22, 2017 elastic modulus is a fundamental parameter in designing concrete structures. Effect of cylinder size on the modulus of elasticity and. Standard test method for static modulus of elasticity and. This paper investigates the use of svm to predict elastic modulus of normal and high strength concrete. Losses due to creep, shrinkage and relaxation are timedependent. This video shows how to find the modulus of elasticity of concrete. Pdf determination of modulus of elasticity of concrete from the. Why is mannings formula more often used than chezy formula in open channel flows. In the design of concrete structures, modulus of elasticity is considerably important that requires to be defined. Modulus of elasticity of concrete civil engineering. Strength, modulus of elasticity, creep and shrinkage of concrete.
The modulus of elasticity of concrete is different for different mixes. The modulus of elasticity of concretes the modulus of elasticity, or youngs modulus, consists in the proportionality coefficient between stress and strain during the elastic regime of a material. In recent years building specifications have even required a specific elastic modulus of. For example, in many buildings the stiffness of the structure, made up of reinforcedsteel concrete beams, is more important than the strength of the structure. Surface repairs must be dimensionally and mechanically compatible with the existing concrete substrate to minimize cracking and ensure that the repair and existing structure act monolithically. The stiffness of a component means how much it deflects under a given load.
The modulus of elasticity is the slope of the stressstrain curve within the proportional limit of a material. The prestress losses are defined as the loss of tensile stress in the prestress steel which acts on the concrete component ofthe prestressed concrete section. Modulus of elasticity of concrete determination and importance in design. Determination of elastic modulus of concrete in accordance. Their results indicate that elastic modulus is reduced with an increase in pvc content. The strength of concrete is dependent on the relative proportion and modulus of. Structural concrete aci31899 and commentary aci 318r99. The laboratory testing was consisted of forty 4 by 8 concrete cylinders collected from a standard. A twostep analytical procedure is proposed to evaluate the quantitative influence of the maximum aggregate size and aggregate gradation on the effective youngs modulus of concrete. For limestone and sandstone aggregates the value should be reduced by 10% and 30% respectively. In addition, the elastic modulus of ac is a design variable for asphalt pavement structural design when elastic layer system theory is employed.
Since the addition of steel fibers to concrete has been shown to increase both the ductility and the fatigue strength of reinforced concrete. Aci plain concrete sm help aci concrete code issues. Concrete yield strength, fc mpa modulus of elasticity, ec mpa modulus of rupture, fr mpa class c 28 25 400 3. Elastic modulus prediction of asphalt concrete journal. Modulus of elasticity and ultimate tensile and yield strength for steel, glass, wood and other common materials. Modulus of elasticity of concrete can be defined as the slope of the line drawn from stress of zero to a compressive stress of 0. The distresses of asphalt pavement, which include fatigue, rutting, and low temperature cracking, are related to the elastic modulus of asphalt concrete ac. Elastic modulus prediction of asphalt concrete journal of. Modulus of elasticity of concrete ec is defined as the ratio of the applied stress to the corresponding strain. Estimation of the static modulus of elasticity of concrete. The test results show that the dynamic elastic modulus of concrete decreases and tends to be stable under the. Concrete yield strength, fc psi modulus of elasticity, ec ksi modulus of rupture, fr psi class c 4000 3645 480 class a 3500 3410 450 class b 3000 3155 415 notes. Efficient design of prestress concrete bridges demands an accurate prediction of prestress losses.
The strength of concrete is dependent on the relative proportion and modulus of elasticity of the aggregate. Evaluation of elastic modulus of fiberreinforced concrete. Not only does it demonstrate the ability of concrete to withstand deformation due to applied stress but also its stiffness. For example, in prestressed concrete structures, elastic shortening of prestressed concrete is one of the main factors contributing to prestress loss. The elastic modulus of concrete is considered one of the most important mechanical properties of concrete for determining the static and dynamic behaviors of new concrete structures. At the low stresses, the elasticity of concrete is constant and at high.
Pdf a practical equation for elastic modulus of concrete. The objectives of this study are to investigate the relationship between static and dynamic elastic moduli determined using shearwave velocity measurements and to demonstrate the practical potential of the shearwave velocity method for in situ dynamic modulus evaluation. Modulus of elasticity of concrete determination and. A specific compressive strength can thus correspond to a variety of. Degradation of dynamic elastic modulus of concrete under. Is anyone familiar with finding the elastic section modulus called sm noted in aci 31805 in the plain concrete section, chapter 22. The test results show that the dynamic elastic modulus of concrete decreases and tends to be stable under the action of periodic temperaturehumidity. Table of concrete design properties fcd, fctm, ecm, fctd. Development of the elastic modulus of concrete under. As we every one is familiar with modulus of elasticity of steel that is 29000ksi. Pdf modulus of elasticity of low strength concrete researchgate. Elastic modulus the stress required to produce unit strain is the measure of stiffness of a material.
To know the accurate value of elastic modulus of a. A high enough value of the modulus of elasticity is a critical requirement in complicated concrete structures and in order to attain it, a number of factors must be taken into account, as it is subject to many. To determine the elastic modulus of the self consolidating concrete mix used piling applications determine if the time dependent strength gain and correlate to a time dependent modulus of elasticity gain. The modulus of elasticity is a property of concrete, which is known for its high variability of values. Evaluating the dynamic elastic modulus of concrete using. Modulus of elasticity of concrete is a key factor for estimating the deformation of structural elements, as well as a fundamental factor for determining modu lar ratio. Chapter 15 modulus of elasticity page 85 tab36 value of modulus of elasticity for some materials material modulus of elasticity gpa aluminium and its alloys 65 73 ceramics 8 12 concrete 15 40 copper 125 diamond lightweight concrete 0,8 2 low alloy steels 200 210 polystyrene 3,2 3,5 silica glass 60 90. The elastic modulus of the hardened paste may be in the order of 1030 gpa and aggregates about 45 to 85 gpa. The results also showed the existence of a definite relation between the actual elastic modulus, density, and compressive strength of concrete. Pdf in turkey, many existing reinforced concrete buildings are in urgent need of seismic retrofitting. The elastic deformation properties of reinforced concrete depend on its composition and especially on the aggregates. In modeling a nonrigid mat foundation by using elastic springs, should a. Modulus of elasticity of concrete is the ratio of normal stress to the corresponding strain for tensile or compressive stresses below the proportional limit of concrete, aci 31814.
The dynamic elastic modulus attenuation pattern and a dynamic elastic modulus degradation model of concrete under periodic temperaturehumidity are investigated. Pdf effective youngs modulus estimation of concrete. The concrete composite is then in the range of 30 to 50 gpa. The objectives of this study are to investigate the relationship between static and dynamic elastic moduli determined using shearwave velocity measurements and to demonstrate the practical potential of the shearwave velocity method for in situ. In the case of concrete, youngs modulus value is connected to compressive strength, which increases with the progress of the hydration process of cement, in a. What is the allowable unit stress in timber columns. Three hundred 150 by 300 mm concrete cylinders were prepared from three different mixtures with target compressive. In addition, the elastic modulus of ac is a design variable for asphalt pavement structural design when elasticlayer system theory is employed. The modulus of elasticity of concrete e c adopted in modified form by the aci code can be calculated by the formula given below.
The elastic modulus of concrete is a very important mechanical parameter reflecting the ability of the concrete to deform elastically. Concrete is a composite mixture of materials coarse, fine aggregates, cement with water. The laboratory testing was consisted of forty 4 by 8. Modulus of elasticity is a measure of stiffness of an elastic material.
The elastic modulus predicted by svm was compared with the experimental data and those from. It is used to describe the elastic properties of objects. Modulus of elasticity for concrete determined from an experimental stress strain relation curve, as described above, is generally termed as static modulus of. The value of elastic modulus of concrete can be obtained using formulas provided by. In recent years building specifications have even required a specific elastic modulus of concrete to be met, mostly to. Estimation of the static modulus of elasticity of concrete using the impulse excitation technique itc07 atcp.
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