• Proceedings of the Korea Concrete Institute Conference
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• 1995.10a
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• pp.159-163
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• 1995

The purpose of this experimental research is to not only devlop the high-strength concrete using sea and river sand, but also investigatc mechanical properites of the high-strength concrete, such as the elastic modulus, the compressive strength of concrete cyllinder, and etc. Also, rational analytical formula for elastic modulus has been proposed together with those for the splitting tensile strength and the flexural strength to be predicted from compressive strength of conccrete cyllinder.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.1390-1395
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• 2005

To analyze the effects of oyster shell particles, inserted in the self-hardening matrix such as cement paste, on strength, homogenization analysis using micro structure was used to estimate and assess the apparent elastic modulus of oyster shell particle. DIB modeling technique was used to represent of the micro structure of oyster shell mixed concrete. The results showed that the apparent elastic modulus of LOS (large oyster shell particle) was changed with the amount of LOS inserted. In particular, when the amount of LOS was 200% of the weight of cement, the apparent elastic modulus of LOS tended to decrease rapidly. This could mean that the strength of oyster shell mixed concrete is much affected by LOS inserted material in mixed ratio of 200%.

• Journal of the Korean Society of Physical Medicine
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• v.7 no.4
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• pp.525-533
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• 2012

PURPOSE: The purpose of this study was to investigate initial effects of the non-elastic taping technique on grip strength and EMG in female with lateral epicondylalgia. METHODS: Twenty-two participants (mean age SD, $52.8{\pm}10.2$ years) with chronic lateral epicondylalgia (mean duration${\pm}$SD, $13.1{\pm}9.9$ months) participated in a placebo control study of an elbow taping technique. Outcome measures were pain-free grip and EMG taken before, immediately after application of tape. RESULTS: The experimental group were more significantly improved grip strength and muscle activity of forearm than control group. CONCLUSION: This study show that non-elastic taping technique is beneficial intervention for increase grip strength and EMG in female with lateral epicondylalgia.

• Geomechanics and Engineering
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• v.21 no.6
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• pp.527-536
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• 2020

An elastic-plastic solution for cavity expansion problem considering strength degradation, undrained condition and initial anisotropic in-situ stress is established based on the Tresca yield criterion and cavity expansion theory. Assumptions of large-strain for plastic region and small-strain for elastic region are adopted, respectively. The initial in-situ stress state of natural soil mass may be anisotropic caused by consolidation history, and the strength degradation of soil mass is caused by structural damage of soil mass in the process of loading analysis (cavity expansion process). Finally, the published solutions are conducted to verify the suitability of this elastic-plastic solution, and the parametric studies are investigated in order to the significance of this study for in-situ soil test.

• Journal of the Korean GEO-environmental Society
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• v.15 no.8
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• pp.51-58
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• 2014

In this research, the composite grounds including original clay and soil-cement were constructed for conducting uniaxial compression test. Strength and deformation properties were analysed using results of laboratory tests with variations of water content of clay, replacement ratio and cement content. Numerical simulation using 3D distinct element method was conducted for soil cement. For strength of composite ground that contains more than cement contents of 15 %, it is more effective to increase cement content than increase of replacement ratio. Strength and elastic modulus of composite ground could be predicted by regression equations using uniaxial compression strength of clay, cement content of soil cement and replacement ratio. For strength and elastic modulus of soil cement, which is most important things for predicting final strength and elastic modulus of composite ground, numerical simulation using the distinct element method adapted bonding model could be used to verify laboratory test, and predict strength and elastic modulus.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.37-42
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• 2001

This paper presents the improved elastic modulus equation more appropriate to predict the modulus of elasticity of structural elements designed and made by high-strength concrete. To propose the elastic modulus equation, more than 300 laboratory specimen tests having the range of 5n to 800kgf/$cm^{2}$ in concrete compressive strength were conducted and analyzed statistically. The equation derived in terms of empirical constant, the elastic moduli of coarse aggregate and mix proportions. Comparison of the proposed elastic modulus equation with the previously suggested equations in the ACI363R, and New-RC were also presented to demonstrate the applicability to practice.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.119-126
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• 2006

The elastic budding strength of a GFRP pipe reinforced with ribs was evaluated. The height and thickness of a rib and the spacing between two adjacent ribs were considered as factors affecting tlje budding strength of the pipe. And also, the ratio of the longitudinal stiffness and transverse stiffness was considered as the parameter affecting on the budding strength because GFRP is orthotropic material. Buckling strengths of various GFRP pipe models with different shapes and stiffness ratio were evaluated by FE analyses and a formula to estimate the elastic buckling strength of a rib-reinforced pipe made of orthotropic material was suggested from the regression with FE analysis results. Analysis results show that a rib-reinforced pipe has superior buckling strength to a general flat pipe and the suggested formula estimates accurate buckling strength of the rib-reinforced pipe.

• Journal of the Korea Concrete Institute
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• v.13 no.6
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• pp.610-618
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• 2001

This paper investigates the relationships between dynamic elastic modulus and static elastic modulus or compressive strength according to curing temperature, aging, and cement type. Based on this investigation, the new model of the relationships we proposed. Impact echo method estimates the resonant frequency of specimens and uniaxial compression test measures the static elastic modulus and compressive strength. Type I and V cement concretes, which have the water-cement ratios of 0.40 and 0.50, are cured under the isothermal curing temperatures of 10, 23, and 50$\^{C}$ Cement type and aging have no large influence on the relationship between dynamic and static elastic modulus, but the ratio of dynamic and static elastic modulus comes close to 1 as temperature increases. Initial chord elastic modulus which is calculated at lower strain level of stress-strain curve, has the similar value to dynamic elastic modulus. The relationship between dynamic elastic modulus and compressive strength has the same tendency as the relationship between dynamic and static elastic modulus according to cement type, temperature and aging. The proposcd relationship equations between dynamic elastic modulus and static elastic modulus or compressive strength properly estimates the variation of relationships according to cement type md temperature.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.6
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• pp.206-215
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• 2017

An experimental program was carried out to investigate the mechanical properties of high-strength concrete. High-strength concrete with compressive strengths of 80 to 120 MPa was tested. Test results are presented regarding effect of water-binder ratio on compressive strength and compressive strength gain. In addition, the effect of curing methods on compressive strength, elastic modulus, splitting tensile strength, and modulus of rupture is investigated. Test results of elastic modulus, splitting tensile strength, and modulus of rupture are compared with predictions from the current design recommendations. Predictions of elastic modulus by using KCI recommendation has good agreement with test results. However, predictions of modulus of rupture by using KCI recommendation underestimate the test results. ACI 363R recommendations predict well test results of splitting tensile strength and modulus of rupture. ACI 363R recommendations for predicting splitting tensile strength and modulus of rupture can be used for high-strength concrete with compressive strengths up to 120 MPa.

• Journal of the Korean Wood Science and Technology
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• v.38 no.5
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• pp.399-404
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• 2010

A new green home designed to save money while at the same time saving the environment with some of the finest green features available in the market. Composite column composed of structural steel and structural glued laminated timber is avery Eco-friendly building products for design building because that use recycled or second hand. For compare to compressive strength of structural glued laminated timber (glulam), structural steel, and composite column (steel-glulam), tested compressive strength of each specimen. 1) structural glued laminated timber : Theoretical compressive strength is 151.6 kN similar to elastic limits. 2) structural steel (H type) : Theoretical compressive strength is 148.2 kN little under the elastic limits. 3) structural steel (D type) : Theoretical compressive strength is 147.3 kN upper than the elastic limits. 4) composite column : Actual elastic limits are about 600 kN. Result in, composite column improve compressive strength of Structural steel column and provide structural stability of the building.