A prediction method of Tensile young''s modulus of concrete at early age Yoshitake Isamu, Rajabipour Farshad, Mimura Yoichi, Scanlon Andrew Advances in civil …
· Early-age Thermal Cracking, usually termed as Early Thermal Cracking is a phenomenon in concrete structures, caused by excessive Tensile Strain in a concrete section above the Tensile capacity of concrete as a result of restraining thermal contraction or due to differential temperature within the cross section.. There are several factors that can influence ETC in concrete …
Lying-tensile concrete creep device was designed, and the device was used at the early age of concrete in measuring the tensile elastic modulus, creep and tensile strength. Meanwhile, the using of the device to determine the parameters has been authenticated. Tests show that the usage of the device not only can determine the early age of concrete creep, elastic modulus, but also can maintain ...
control the early-age stress behavior (Young''s modulus, creep, relaxation, autogeneous deformation, and coef ﬁcient of thermal dilation) and on the early-age stress response are investigated in a two-part study. Inpart one [11], hydrationwas used as a fundamental measure of aging. Therein, key
results from concrete cubes, the modeling method and experimental procedures used in this study were validated to exhibit reasonable accuracy in terms of temperature and strain predictions. The thermal and stress analysis models can be used to calculate the temperature profile and thermal stress development histories for early age concrete.
Mang [18] proposed a 3-D material model for the simulation of early-age cracking of concrete based on the Rankine criterion formulated in the framework of multi surface chemoplasticity. Gawin, Pesavento, and Schre er [19, 20] proposed a solidi cation-type early-age model and extended it to account for coupled hygro-thermo-
Predictions and verifications of early-age stress development in hydrating blended cement concrete. ... Tensile Creep Behavior of Concrete Subject to Constant Restraint at Very Early Ages. By Will Hansen. Identification of viscoelastic behavior for early-age concrete based …
where f t (t) is the tensile strength of concrete at age of t, E (t) is the elastic modulus of concrete at the age of t, ε s h − e (t) is the effective shrinkage strain at the age of t.When η < 0.7, the concrete does not crack; when 0.7 ≤ η ≤ 1.0, the concrete may crack; when η > 1.0, the concrete cracks.
deformations. Cracking is investigated both at early ages, during hydration, and at mature age when the final properties of the concrete are reached. One of the most important material characteristics of the concrete at early ages, the Young''s modulus is determined by means of a dynamic method called the resonance frequency method.
test. Three concrete mixes using Ordinary Portland Cement (OPC) were tested. The three concrete mixes were cast, and each underwent the ring tests up to cracking. Mechanical properties of concrete at the age of 1, 3, 7, 14, and 28 days were tested to find the compressive strength, tensile strength and Young''s Modulus of concrete.
· In particular, the time-dependent development estimation of modulus of elasticity during curing ages, especially at early age, is needed for structural health monitoring (SHM). In this study, cylindrical specimens in accordance to AS 1012.9 measuring 100 mm in …
· Concrete is a composite mixture of materials (coarse, fine aggregates, cement with water). It has high compressive strength and low tensile strength. The modulus of elasticity of concrete is different for different mixes. The concrete fails under the tensile stresses.
To enable a direct estimation of the tensile modulus of concrete, a simple three-phase composite model is developed based on random distributions of coarse aggregate, mortar, and air void phases. The model predictions show good agreement with experimental measurements of tensile modulus at early age.
Table 5: A Prediction Method of Tensile Young''s Modulus of Concrete at Early Age
To evaluate the validity of this approach, the tensile Young''s moduli of 6 concrete and mortar mixtures are measured using a direct tension test. The results show that the tensile moduli are approximately 1.0–1.3-times larger than the compressive moduli within the material''s first week of age.
Measurement and modeling of concrete tensile creep and shrinkage at early age. Matthew D''Ambrosia. Zachary Grasley. David Lange. Matthew D''Ambrosia. ... 37 Full PDFs related to this paper. READ PAPER. Measurement and modeling of concrete tensile creep and shrinkage at early age. Download. Measurement and modeling of concrete tensile creep and ...
· SRA reduces the dynamic elastic modulus at early age without affecting it in later period. Finally, a multiscale micromechanics approach coupled with a hydration model CEMHYD3D and percolation theory is utilized to predict the elastic modulus of cement paste, and the predictive results by the model are in accordance with the experimental data.
Units of Elastic Modulus. Units of elastic modulus are followings: In SI unit MPa or N/mm 2 or KN/m 2. In FPS unit psi or ksi or psf or ksf. Modulus of Elasticity of Concrete. Modulus of Elasticity of Concrete can be defined as the slope of the line drawn from stress of zero to a compressive stress of 0.45f'' c. As concrete is a heterogeneous ...
2. Dynamic modulus. 1. Static Elastic Modulus: The strains obtained as above are plotted against stress and a curve is obtained as shown in Fig. 15.5. As concrete is an imperfect elastic material, stress strain diagram is a curved line. Hence three methods can be used to determine the modulus of elasticity. (a) Initial tangent modulus.
from that under compression. The strong age-dependent properties of tensile creep have been found in concrete loaded within the first 24 h after setting. Modifications to existing compressive creep models have been made to satisfactorily capture the early-age tensile creep behavior (østergaard et …
· Highlights Tensile strength and Young''s modulus of fly-ash concrete at early age were examined by using a prismatic specimen with an embedded reinforcing bar. Three fly-ash concretes with a cement-replacement ratio of 20% were placed and cured in field environmental conditions. Empirical formulae for both strength and Young''s modulus were presented.
The prediction of the evolution of Young''s modulus with the advancement of the hydration reaction is the subject of a number of studies. From a macroscopic point of view, the evolution of mechanical properties of early age cementitious materials can be associated to the degree of hydration. A phenomenological rela-
Predictions and veriﬁcations of early-age stress development in hydrating blended cement concrete Ivindra Panea,⁎, Will Hansenb a Department of Civil Engineering, Bandung Institute of Technology, Ganeca 10, Bandung 40132, Indonesia b Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor MI 48109, USA ARTICLE INFO ABSTRACT
Yoshitake et al. [20] proposed a prediction formula of tensile Young''s moduli of concrete at early age. Swaddiwudiwudhipong et al. [21] conducted a uniaxial tension test of concrete incorporating ...
· Cracking occurs when the tensile stress in concrete exceeds its tensile strength. Early-age stress development in concrete is influenced by temperature changes, modulus of elasticity, creep or stress relaxation, shrinkage and coefficient of thermal expansion, and the degree of restraint.
Summary This paper discusses some of the models currently available for the prediction of the modulus of elasticity of concrete. A new model is proposed which gives a satisfactory prediction for a wide variety of aggregates and concrete mixes. The same model explains satisfactorily the isolated effect of the elastic modulus of the aggregate on the creep and creep recovery of concrete.
Fracture energy of the concrete and modulus of elasticity values obtained in this study correlate ... representation of the early age tensile strength of the concrete. Nu,c 0 = k 1 fcc,200 0.5 k 2 h ef 2 k 3/h 0.5 (1) where, Nu,c ... method prediction formula because …
· Methods of testing concrete - Method 17: Determination of the static chord modulus of elasticity and Poisson''s ratio of concrete specimens (Reconfirmed 2014) (AS 1012.17–1997 R2014), Committee BD-42, Standards Australia Sydney, NSW, Australia.
フルテキストURL: 2011010397.pdf ( 1.6MB ) 2013-12-19: タイトル: A prediction method of Tensile young''s modulus of concrete at early age: : Yoshitake, Isamu
The understanding of stress relaxation and tensile creep behavior is extremely important in accurate stress analysis and crack prediction of early-age concrete. The free shrinkage deformations of concrete with different strength grade were examined. The early-age tensile elastic modulus of concrete was investigated through temperature-stress testing machine.
Graduate Theses and Dissertations Iowa State University Capstones, Theses and Dissertations 2012 Predicting early-age thermal behavior of mass concrete for bridge foudnation
and tensile Young''s modulus at early age. Yoshitake et al. [4] also investigated tensile properties of high vol-ume fly-ash (HVFA) concrete. Young''s modulus in Japan is generally a secant modulus obtained from a compres-sion test. Mimura et al. [5] reported that the tensile Young''s modulus based on the direct tension test by
The tensile strength, Young''s modulus, and fracture energy of early-age concrete are all found to increase very slowly during the first 3 hours or so, but significantly increase thereafter. Strong correlations are shown to exist between these three parameters, especially between tensile strength and …
To measure the tensile modulus, the tensile force is applied to the specimen at strain intervals of 10 × 10-6 order to prevent failure of specimen, the maximum strain during the test is set at 60 × 10-6.Since the plastic strain of concrete at early age may comprise a high percentage of the total strain measured, the tensile modulus is obtained from the unloading branches of the stress ...