The results show that the curing method strongly affects not only the development, but. Factors affecting deflections of rcc beams and slabs. Factors affecting the modulus of elasticity of concrete. Concrete compressive strength could be higher as much as 15% than specified and increase modulus of elasticity by 7%. Modulus of elasticity of concrete is a key factor for. Modulus of elasticity iof concrete affected by elastic moduli. Following factors affect the value of modulus of elasticity. The modulus of elasticity of high performance concrete. Factors affecting workability of concrete civil engineering. Physically it indicates a materials resistance to being deformed when a. An evaluation of factors affecting the tensile properties of. Elasticity modulus of concrete with recycled aggregate. The main factors which may affect the values determination of modulus of.
Factors affecting the modulus of elasticity of concrete may 23, 2018 by kathir leave a comment since concrete is a multiphase solid, no direct relationship can exist between its density and modulus as in singlephase solids such as metals. Several of the numerical approximations presented for the stressstrain diagram can take some of these effects into consideration. The modulus of elasticity of concrete is a function of the modulus of elasticity of the aggregates and the cement matrix and their relative proportions. Evaluating the dynamic elastic modulus of concrete using. Many factors have been shown to influence the flexural tensile strength of concrete, particularly the level of stress, size, age and confinement to concrete flexure member, etc.
Physically it indicates a materials resistance to being deformed when a stress is applied to it. A parametric study was conducted to explore the effect of the interfacial transition zone itz or interphase on the overall elastic modulus of the cntreinforced cement. Shrinkage deformation affects durability, serviceability, longterm reliability, and structural integrity of concrete. Modulus of elasticity of lightweight concrete containing. The elastic modulus was found to be the best indicator for identifying the progression of asr in concrete. In recent years building specifications have even required a specific elastic modulus of concrete to be met, mostly to. Elastic properties of concrete elasticity, creep and shrinkage. Modulus of elasticity of concrete civil engineering. Motivation and goal the modulus of elasticity is a fundamental property for concrete and it has become increasingly common for designers to specify a minimum value to be met. Most design specifications, such as the american association of state highways and transportation officials aashto bridge specifications, contain a constant value for the moe based on the unit weight of concrete and the concrete. Mar 09, 2017 modulus of elasticity of concrete as per is 456. Procedure for measuring the modulus of elasticity of concrete cores and cylinders rev. Properties of hardened concrete strength, sjrinkage.
For isotropic materials, the presence of fractures affects the young and the shear modulus perpendicular to the planes of the cracks, which decrease youngs modulus faster than the shear modulus as the fracture density increases, indicating that the presence of cracks makes bodies brittler. Creep does not necessarily cause concrete to fail or break apart. The technical and scientific knowledge of the physical and mechanical behavior of concrete with recycled aggregates is not well established, and this is a knowledge gap, especially considering the use in structural elements. University of canterbury, christchurch, new zealand. The experimental evaluation of the modulus of elasticity of conventional concretes and with the re. Therefore, the manufacture should choose the material in such a way that it should regain its elastic property even when it is subjected to large number of cycles of stress. It is one of the most important factors which affect the modulus of elasticity. Water tightness impermeability rate of strength gain of concrete. Properties of hardened concrete strength, sjrinkage, creep. The strength of concrete is dependent on the relative proportion and modulus of elasticity of the aggregate.
Modulus of elasticity of concrete concrete technology. The ratio between static and dynamic modulus of elasticity in normal and high strength concrete abstract there is a simple linear relationship between the static and dynamic elastic module, this lead to hope that using dynamic elastic modulus may remove the problems in measuring the static elastic modulus of concrete. What are properties of hardened concretegoverning factors. Some factors affecting the dynamic modulus of elasticity of. Chapter 1 properties of reinforced concrete strength of. The mechanism of geopolymerisation may consist of dissolution, transportation or orientation, and. The different types of shear failure of reinforced concrete rectangular and tbeams are described in order to show that the shear strength depends on factors additional to those recognized by the design formulae. The type of aggregate and the size of the aggregate particles can also influence the tensile strength. The concrete technology notes pdf ct notes pdf book starts with the topics covering portland cement, mineral and chemical admixtures, classification of aggregate, factors affecting workability, water cement ratio, compression tests, factors in the choice of mix. Strength, modulus of elasticity, creep and shrinkage of concrete. The modulus of elasticity young s modulus e is a material property, that describes its stiffness and is therefore one of the most important properties of solid materials. It is found that bodies lose their elastic limit, due to elastic fatigue. Sep 16, 20 civildigital powerpoint presentations building technology what are properties of hardened concretegoverning factors properties of hardened concrete properties of hardened concrete are explained on the basis of its strength and performance under various types of force actions and conditions.
Modulus of elasticity iof concrete affected by elastic. Stress, strain and youngs modulus calculator epsilon. Effect of cylinder size on the modulus of elasticity and. 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. Some factors affecting the dynamic modulus of elasticity. Modulus of elasticity also known as elastic modulus, the coefficient of elasticity of a material is a number which is defined by the ratio of the applied stress to the corresponding strain within the elastic limit.
It is defined as ratio of normal stress to longitudinal strain within the limit of proportionality. Loading conditions and moisture content of specimens. Estimation of the static modulus of elasticity of concrete using the impulse excitation technique itc07 atcp. Laboratory tests showed the equation to produce good results over a wide range of variables. The elastisitymodulus or emodulus is a property of a material like concrete or steel whichs tells how much tension is needed to make it a little bit longer or shorter when you pull at 2 ends of a steal beam itll be a bit longer then when you press it together. Factors affecting price elasticity of demand economics. Youngs modulus does depend on orientation of a single crystal material.
What are the factors affecting young modulus of elasticity. Pdf modulus of elasticity of low strength concrete. Air travel and train travel are weak substitutes for intercontinental flights but closer substitutes for journeys of around 200400km e. 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. Pauw, static modulus of elasticity of concrete as affected by density, aci journal proceedings, vol. High strength concrete is characterized by a dense interfacial transition zone itz and behaves differently from low strength concrete. A general equation is derived which expresses the modulus of elasticity of concrete or mortar in terms of an empirical constant the elastic moduli of the cement matrix and aggregate constituents, and the mix proportions. There are a few normalised methods of assessing the elastic properties of. Here you can download the free lecture notes of concrete technology pdf notes ct pdf notes with multiple file links to download. Jan 22, 2017 elastic modulus is a fundamental parameter in designing concrete structures. Factors in the choice of mix proportions bis and aci methods of mix design. Development of the elastic modulus of concrete under different. Elasticity modulus, shrinkage, and creep of highstrength.
Results of experiments on the influence on shear strength of the size of the compression zone of the beam and of hooks on plain and deformed bars are presented. In the theory of reinforced concrete, it is assumed that concrete is elastic, isotropic. Another aim is to find ways to determine the static modulus of elasticity of concrete by nondestructive means primarily ultrasonic pulse method, resonance method and use of electronic rebound hammers, thus to determine the possibility of creating calibration curve for ndt determination of the modulus of elasticity. Modulus of elasticity of concrete is the ratio of the stress to the strain of the concrete. The thesis aims to describe and evaluate the important factors that affect the final value of concrete modulus of elasticity, especially those that can be influenced during construction. While there are many factors for high seismic vulnerability of existing buildings, poor quality of concrete is a major and widespread problem for. The modulus of elasticity youngs modulus e is a material property, that describes its stiffness and is therefore one of the most important properties of solid materials. Kennedy, discusses factors important in determining the tensile strength of asphalttreated materials and reports findings of an evaluation of eight of these factors. Pdf key factors affecting the compressive strength of. Structural concrete aci31899 and commentary aci 318r99. The influence of concrete composition on youngs modulus core. The relationship between modulus of elasticity, e, and the product of compressive strength to the power and unit weight to the sec.
Parameters affecting the modulus of elasticity of concretes the elastic properties of concretes largely depend on the properties of their components. It might vary along the member length and is likely to reach average in its influence on deflection. Creep is factored in when concrete structures are designed. Home tools stress, strain and youngs modulus calculator calculators for stress, strain and youngs modulus modulus of elasticity, elastic modulus stress, strain and youngs modulus are all factors linked to the performance of a material in a particular setting. Aci 31808, normal weight concrete the modulus of elasticity of concrete is, ec 4700 vfc mpa and. A study of factors affecting the flexural tensile strength. How to fit a concrete cylinder with compressometerextensometer for elasticity modulus test duration. The strength of concrete is basically referred to compressive strength and it depends upon three factors. Any concrete pavement, built of any thickness, will. Factors affecting durability of concrete durability of concrete depends upon the following factors. Modulus of elasticity of concrete ec is defined as the ratio of the applied stress to the corresponding strain.
Concrete modulus of rupture is more changeable than compressive strength. The concrete technology notes pdf ct notes pdf book starts with the topics covering portland cement, mineral and chemical admixtures, classification of aggregate, factors affecting workability, water cement ratio, compression tests, factors. Modulus of elasticity of concrete increases approximately with the square root of the strength. The number of close substitutes the more close substitutes there are in the market, the more elastic is demand because consumers find it easy to switch. Experimental determination of factors affecting the static modulus of elasticity of concrete using nondestructive testing methods. Modulus of elasticity of concrete the modulus of elasticity of concrete e c adopted in modified form by the aci code is given by with normalweight, normaldensity concrete these two relations can be simplified to where e c modulus of elasticity of concrete, lbin 2 mpa. Most of these codes are valid up to 50 mpa, the usual limit for normal concretes. Cement content mix must be designed to ensure cohesion and prevent segregation and bleeding.
As a consequence, such models can only be used to evaluate the effects produced by the concrete components on the modulus of elasticity. This stronger delivered concrete as well the concrete age may give reason for that the modulus of elasticity used in design gives the correct structural deformations. Estimation of the static modulus of elasticity of concrete. The effect of the itz properties on the elastic modulus of the cntreinforced cement was investigated using a fourphase axisymmetric model consisting of a single cnt aligned at the center of composite unit. The modulus of elasticity is a property of concrete, which is known for its high variability of. Modulus of elasticity results of dynamic e tests are given in table 4, for water cured prisms, with 10% sf.
Concrete technology 11 factors affecting the selection of repair materials 11 factors affecting the selection of repair materials there are a number of factors such as strength, durability, thermal coefficient of thermal expansion, permeability, low dry shrinkage, chemical and electrical properties, curing, and cost that must be considered to select the most appropriate. The concrete members, in general, are of large continuous size and have at least minimum reinforcement introducing a confining effect to the concrete. For a more realistic interstory ratio prediction, the modulus of. If cement is reduced, then at fixed wc ratio the workability will be reduced leading to inadequate compaction. Prestress losses assumed for bridge girder design and deflection analyses are dependent on the concrete modulus of elasticity moe. Concrete technology notes pdf ct notes pdf eduhub sw. Not only does it demonstrate the ability of concrete to withstand deformation due to applied stress but also its stiffness. Effect of a time dependent concrete modulus of elasticity. Previous research on geopolymer material the term geopolymer describing a family of mineral binders those have a polymeric siliconoxygenaluminum framework structure. Factors affecting youngs modulus the modulus is closely related to the binding energies of the atoms. Higher strengths give higher value of modulus of elasticity. Some factors in the shear strength of reinforced concrete.
Experimental determination of factors affecting the static. Factors affecting the tensile properties of concrete. Modulus of elasticity dynamic modulus of elasticity poissons ratio creep of concrete factors influencing creep relation between creep and time effects of creep shrinkage types of shrinkage. In turkey, many existing reinforced concrete buildings are in urgent need of seismic retrofitting.
Pdf this contribution aims to highlight, from an experimental point of view, the key factors affecting the compressive strength of foamed concrete. Pdf influence of coarse aggregate on concretes elasticity modulus. The ts500 equation eqn 21 generally overestimates the modulus of elasticity of low strength concrete ispir et al. Test result of the elastic modulus is usually available for major structures but it is very rare that at least a shortterm creep test is carried. Binding forces, and thus the modulus of elasticity, are typically higher for high melting point materials. Resilient modulus is an important property for asphalt concrete design and for. To determine the modulus of elasticity of concrete precisely is very important for structures that require strict control of the deformability. Procedure overview the determination of the modulus of elasticity for cylindrical concrete samples such as molded cylinders and drilled cores is outlined in this procedure.
Moreover, because of the stressstrain characteristics of concrete, it is probable that the modulus of elasticity of concrete, regardless of how it is determined, is a function of the stress intensity. Modulus of rupture modulus of elasticity modulus of subgrade reaction 198693 rigid pavement design equation. Factors governing the strength and elastic properties of a. Youngs modulus of concrete depends on many other factors such as moisture, the. Elasticity theory of concrete and prediction of static emodulus for. Estimation of the static modulus of elasticity of concrete using the impulse excitation technique itc07 atcp br 1 1. Factors affecting elasticity in engineering physics tech. Factors affecting modulus of elasticity as explained earlier, one of the important factors affecting the modulus of elasticity of concrete is the strength of concrete.
Aci committee 469, standard test method for static modulus of elasticity and poissons ratio of concrete in compression, american concrete institute, farmington hills, mich, usa, 2014. Effect of stress on the dynamic modulus of concrete. For the pairs of prisms tested on each occasion, standard deviations were calculated. The primary objective of this study is to investigate the effect of cylinder size 100 by 200 mm and 150 by 300 mm on empirical equations that relate static and dynamic elastic moduli of concrete and static elastic modulus and compressive strength of concrete. Since concrete is a composite material, consisting of cement paste and aggregate, its modulus of elasticity depends on the moduli of elasticity and the volume fractions of cement paste and aggregate. International codes propose a wide variety of formulae which establish a relationship between modulus of elasticity and compressive strength. Concrete is a composite consisting of matrix and aggregates. This can be represented in many ways such as the relationship between ratio of mix or watercement ratio. Mar 04, 2016 compressive strength of concrete is the most important properties of concrete the characteristic strength that is concrete grade is measured by 28day cylindercube strength. More over, the modulus of elasticity in design is based on concrete 28 day strength, but the concrete, when becomes older, increases its strength and also modulus. A practical equation for elastic modulus of concrete. When a load is applied to concrete, it experiences an instantaneous elastic strain which develops into creep strain if the load is sustained. Standard cylinder 150x300 mm or 150x100 cube with aggregate size of which is not exceeding 25mm is used to determine the strength.
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