Evaluating the Dynamic Elastic Modulus of Concrete Using Shear-Wave Velocity Measurements

Lee, Byung‐Jae; Kee, Seong‐Hoon; Oh, Taegon; Kim, Seong Su

doi:10.1155/2017/1651753

Cited by 48 publications

(35 citation statements)

References 14 publications

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“…where ⍴ is the gelatin's density (Lee et al, ). For a weak material like gelatin, these shear waves can be quite slow (~1 m/s) and are easy to track with a simple camera or the unaided eye.…”

Section: Methodsmentioning

confidence: 99%

How Magmatic Storage Regions Attract and Repel Propagating Dikes

Pansino

Taisne

2019

JGR Solid Earth

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We investigate the effect of magmatic reservoir pressure on the propagation of dikes that approach from below, using analogue experiments. We injected oil into gelatin and observed how dike propagation responded to the stress field around a pressurized, spherical reservoir, filled with water. The reservoir was modeled using two different setups: one simply using an inflatable rubber balloon and the other by constructing a liquid-filled cavity. We find that the dike's response is dependent on the sign of the reservoir pressure (i.e., inflated/overpressurized and deflated/underpressurized) as well as on the dike's initial orientation (i.e., if its strike is radially, circumferentially, or obliquely oriented to the reservoir). Dikes that are initially strike radial respond, respectively, by propagating toward or away from overpressurized or underpressurized reservoirs, taking advantage of the reservoir's hoop stresses. Otherwise-oriented dikes respond by changing orientation, twisting and curling into a form dictated by the principal stresses in the medium. For overpressurized reservoirs, they are coaxed to propagate radially to, and therefore approach, the reservoir. For underpressurized reservoirs, they generally reorient to propagate tangentially, which causes them to avoid the reservoir. The magnitude of reservoir pressure controls at which distance dikes can be affected, and, at natural scales, we estimate that this occurs within a radius of a few tens of kilometers. This diminishes with time, due to viscous stress relaxation of the crust, which will occur on a timescale of hundreds of years.Plain Language Summary Magma commonly moves up toward the surface by creating cracks in the crust. It flows inside of the cracks and propagates by applying pressure that drives the flow and damages surrounding rocks. Nature always finds the easiest path for the crack, so if it takes less pressure to push apart the ground vertically or horizontally, the crack will grow accordingly. As it makes its way to the surface, it may encounter local stress variations that change its propagating direction. This applies near magma storage regions, below volcanoes. If such a region is highly pressurized or deflated, then nearby cracks will "feel" the change in their surrounding conditions and react by aligning in a direction of favorable stress. This makes it look like they are growing toward or circling around the storage region, respectively. We studied this behavior using scaled model experiments in laboratory conditions. We use different types of materials to represent nature, such as gelatin as rock and oil as magma. We were able to show how these cracks change shape for different reservoir pressures. We found that after a large eruption, subsequent eruptions are more likely to occur farther from the summit of a volcano.

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Section: Methodsmentioning

confidence: 99%

How Magmatic Storage Regions Attract and Repel Propagating Dikes

Pansino

Taisne

2019

JGR Solid Earth

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“…This holds true for the rigidity and stiffness. Concrete with a higher elastic modulus will be stiffer and less prone to the deflections for the beams [15][16][17]. Therefore, higher elastic modulus values will be preferable in the design of concrete structures, since concrete with higher elastic modulus will tend to deflect less than concrete with a lower elastic modulus value.…”

Section: Modulus Of Elasticity (E C )mentioning

confidence: 99%

Effects of Elastic Modulus on Behavior of Polymer Coated Fiber Modified Short Concrete Beams

Korkmaz¹,

Kocak²,

Gafy³

et al. 2019

AJCBM

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Polymers have been one of the mostly and effectively used materials all over the world recently. They have been gaining popularity for various purposes in the concrete industry last couple of decades as well. They have the ability to increase the strength and durability of the concrete products. Moreover, polymers in concrete industry can also be considered as a sustainable product since they achieve the requirements of the consumers without adversely affecting the environment, health and the economy. Fiber-modified short beams are structural members commonly used in construction industry. To enhance their physical properties, various methods have been developed; however, most of them have been considered costly and time consuming. In this study, it was concluded that one major physical property, strength, of fiber-modified concrete short beams could be improved by using polymer as a coating material. Hence, the capacity and probably the service life of those beams could be improved. Furthermore, proper polymer coating may reduce the maintenance costs. In this study, polymer coating is applied for fiber modified short concrete beams. The change in modulus of elasticity was investigated as the identifying parameter between various coated short beams since it is an important parameter in the design and analysis processes of the beams. The elastic moduli for various regions of the world were derived from compressive strength results. The maximum deflection values were computed for each region and each polymer coating as well. Finally, the most effective polymer type and coating were discovered according to the maximum deflections obtained for simply supported beam approach.

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“…[15]. However, if the range of Ei is set to (10-50 µ) as in the previous studies, the correlation with Ec may be small, as the measured value in the initial part of the stress-strain curve is unstable, and has high variation [9,16]. Therefore, if the correct Ei value is extracted, the correlation of Ei-Ec is expected to be greater than that of Ed-Ec.…”

Section: Introductionmentioning

confidence: 97%

“…Among ultrasonic test methods, a pressure wave (P-wave) measurement provides easy and convenient testing, but the distribution of the data is large, owing to uneven distributions of aggregates, moisture, and voids in the test piece. In addition, although a large correlation between Ec and compressive strength (fc) has been reported as a result of using a shear wave (S-wave), which has a larger energy than a P-wave, it is difficult to measure and obtain consistent data (especially at low ages), owing to the influences of voids and moisture in the concrete [7][8][9][10]. The resonance frequency test is known for consistently predicting the Ed with less fluctuation in the collected data, as it is simple to measure and grasps the overall dynamic characteristics of the specimen.…”

Section: Introductionmentioning

confidence: 99%

Study on Prediction and Application of Initial Chord Elastic Modulus with Resonance Frequency Test of ASTM C 215

Yoon

Choi

2020

Applied Sciences

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For accurate design, construction, and maintenance, it is important to identify the elastic modulus of concrete. This is usually achieved using a destructive test based on American Society for Testing and Materials (ASTM) C469. However, obtaining an appropriate static elastic modulus (Ec) requires many specimens, and the testing is difficult and time-consuming. Thus, a dynamic elastic modulus (Ed) is often obtained through a natural frequency for a specific size (e.g., the longitudinal (LT) or transverse (TR) mode) based on a resonance frequency test. However, this method uses a gradient at a very low-stress part of the stress–strain curve and assumes a completely elastic body. In fact, the initial chord elastic modulus (Ei) of the stress–strain curve in a concrete fracture test differs from the Ed, owing to the non-homogeneity and inelasticity of the concrete. The Ei of the experimental value may be more accurate. In this study, the Ei was predicted using machine learning methods for natural frequencies. The prediction accuracy for Ei was analyzed based on f1–f4, as calculated through the LT and TR modes. The predicted Ei had higher correlations with the actual Ec and compressive strength (fc) than Ed. Thus, more accurate prediction of concrete mechanical properties is possible.

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Evaluating the Dynamic Elastic Modulus of Concrete Using Shear-Wave Velocity Measurements

Cited by 48 publications

References 14 publications

How Magmatic Storage Regions Attract and Repel Propagating Dikes

How Magmatic Storage Regions Attract and Repel Propagating Dikes

Effects of Elastic Modulus on Behavior of Polymer Coated Fiber Modified Short Concrete Beams

Study on Prediction and Application of Initial Chord Elastic Modulus with Resonance Frequency Test of ASTM C 215

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