• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.240-243
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• 2004

A new shear connection for the application of precast decks to PSC girders was proposed and push-off tests were conducted to evaluate the horizontal shear strength of the shear connection. Major parameters of the tests were connector type, shank area, vertical load, surface condition and bedding height. Judging from the test results, shear strength of the suggested shear connection was proportional to the shank area and yield strength of the connectors and was in inverse proportion to the bedding height. Shear connection with shear key at the surface showed better performance. An empirical equation for the evaluation of the shear strength of the shear connection without considering bond strength was proposed and it showed good correlation with the test results.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.1065-1078
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• 2009

The shear strength has been managed as an important factor in soil mechanics. The shear strength estimation model was developed to evaluate the shear strength using only a few soil properties by the linear regression analysis model which is one of the statistical methods. The shear strength is divided into two part; one is the internal friction angle ($\Phi$) and the other is the cohesion (c). Therefore, some valid soil factors among the results of soil tests are selected through the correlation analysis using SPSS and then the model are formulated by the linear regression analysis based on the relationship between factors. Also, the developed model is compared with the result of direct shear test to prove the rationality of model. As the results of analysis about relationship between soil properties and shear strength, the internal friction angle is highly influenced by the void ratio and the dry unit weight and the cohesion is mainly influenced by the void ratio, the dry unit weight and the plastic index. Meanwhile, the shear strength estimated by the developed model is similar with that of the direct shear test. Therefore, the developed model may be used to estimate the shear strength of soils in the same condition of study area.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.289-292
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• 2006

In this research, bending shear test of HPFRCC beams is conducted to obtain the shear strength of HPFRCC beams. Parameters are ratio of volume percentage of fibers. Also, the uniaxial tensile test of HPFRCC is conducted to obtain the tensile cracking stress of each parameters. From the uniaxial tensile test result, the shear strength of HPFRCC beams can be calculated by using the preexisting shear analysis model. Then, the shear strengths of bending shear test result and analysis result are compared.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.03a
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• pp.529-532
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• 1999

This paper presented the characteristics of shear strength of domestic municipal wastes including S landfill wastes. A series of large direct shear tests were peformed with waste specimens sampled from S landfill located in middle area of domestic land. Investigated items were cohesion and internal friction angle of shear strength parameter. The test result was compared with existing test data. The research results showed that cohesion 0.1296∼0.1340kg/$\textrm{cm}^2$ and angle of friction 22.1$^{\circ}$∼25.3$^{\circ}$for S landfill wastes, cohesion 0∼0.381kg/$\textrm{cm}^2$ and friction angle 22.1$^{\circ}$∼41.3$^{\circ}$ for domestic landfill wastes.

• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.4
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• pp.123-128
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• 2002

This study was performed to use fiber mixed soil which has clayey soil or sandy soil with fibrillated fiber or monofilament fiber on purpose of construction materials, filling materials, and back filling materials. In addition, this study was conducted to analyze strength properties and fiber reinforcing effect with fiber mixed soil by direct-shear test. In case of fibrillated fiber mixed soil, the more quantity of fiber was in both cohesive soil and sandy soil, the larger shear stress was in respective step of normal load. The respective mixed soil at 0.5% and 0.1% mixing ratio of monofilament fiber mixed soil showed maximum shear stress. According to unconfined compression or direct-shear test, making specimen of the monofilament fiber mixed soil, it is required to be careful and stable mixing method, while it is expected that monofilament fiber mixed soil doesn't increase strength.

• Architectural research
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• v.20 no.3
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• pp.75-82
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• 2018

The aim of the study is to evaluate the concrete shear strength and structural behavior of two general beams and eight shape memory alloys (SMAs)-reinforced beams under the flexural test. This work compares the existing reference formula for concrete shear strength with test result to provide the basic data for the design of highly intelligent reinforced concrete (hereinafter, HIRC) beams. The evaluation of the concrete shear strength was performed with effective depth (d=65, 70, 80), SMA diameter change (ø=2.0, 2.5) as the main variables of the specimens. For the relationship between the effective depth and the $V_{\exp}/V_{cal}$, the test result shows that the concrete shear strength gradually approaches 1.0 as the effective depth length increase. For the AIJ formula, the specimens are approached evenly for comparison between $V_{\exp}/V_{cal}$ and the by-product (garnet, fly-ash) reinforced specimen; however, other formulas indicate a deviation.

• Journal of the Korean Geotechnical Society
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• v.36 no.9
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• pp.33-44
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• 2020

In order to analyze the shear strength characteristics of the grout with sudden gelation in the pre-hardening state, the viscosity of the mixture and the indoor vane shear test were performed. The grout was prepared according to the water-cement (w/c) ratio and the shear strength test was conducted. The plastic-state shear strength of grout was affected by the w/c ratio, so the lower the w/c ratio, the higher the initial shear strength was, and the longer the curing time was, the higher the shear strength was. The maximum shear strength occurred at the faster rotation angle as the higher shear strength was developed, and the lower shear strength occurred at the larger rotation angle. In addition, it was confirmed that the pre-hardening grout rapidly decreased in strength after the maximum shear strength was gained, and converged at a certain level after the rotation angle of the vane blade was about 70° to 90°.

• Journal of Technologic Dentistry
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• v.38 no.4
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• pp.291-298
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• 2016

Purpose: This study was to evaluate the effect of coloring liquids on the shear bond strength between zirconia and veneering ceramic. Methods: Zirconia(15 mm in diameter, 2.5 mm in thickness; n=40) used in the experiment were divided into 5 groups depending on the coloring liquid. Each specimen were polished using a polishing machine(LaboPol-2, Struers, UK). A cylinder of veneering porcelain(6 mm in diameter, 3 mm in thickness) was fabricated and fired on zirconia surfaces. The shear bond strength was measured using a universal testing machine(Model 4302, Instron, USA). All data were analyzed statistically using a one-way ANOVA and Tukey's multiple comparisons test. After the shear bond test, fracture surfaces were examined by SEM. Results: Colored zirconia showed a higher shear bonding strength than that of uncolored zirconia except for colored zirconia immersed in Zirkonzahn coloring liquid. In particular, colored zirconia immersed in Kuwotech coloring liquid showed the highest shear bond strength. After the shear bond test, mixed failure patterns were mainly observed in the failure between zirconia and veneering ceramic. Conclusion: Coloring liquid enhanced the shear bond strength zirconia and veneering ceramic than uncolored zirconia.

• The Journal of Korean Academy of Prosthodontics
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• v.42 no.6
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• pp.654-663
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• 2004

Statement of problem. According to the fracture pattern in several reports, fractures most frequently occur in the interface between the ceromer and the substructure. Purpose. The aim of this in vitro study was to compare the macro shear bond strength and microshear bond strength of a ceromer bonded to a fiber reinforced composite (FRC) as well as metal alloys. Material and methods. Ten of the following substructures, type II gold alloy, Co-Cr alloy, Ni-Cr alloy, and FRC (Vectris) substructures with a 12 mm in diameter, were imbedded in acrylic resin and ground with 400, and 1, 000-grit sandpaper. The metal primer and wetting agent were applied to the sandblasted bonding area of the metal specimens and the FRC specimens, respectively. The ceromer was placed onto a 6 mm diameter and 3 mm height mold in the macro-shear test and 1 mm diameter and 2 mm height mold in the micro-shear test, and then polymerized. The macro- and micro-shear bond strength were measured using a universal testing machine and a micro-shear tester, respectively. The macro- and micro-shear strength were analyzed with ANOVA and a post-hoc Scheffe adjustment ($\alpha$ = .05). The fracture surfaces of the crowns were then examined by scanning electron microscopy to determine the mode of failure. Chi-square test was used to identify the differences in the failure mode. Results. The macro-shear strength and the micro-shear strength differed significantly with the types of substructure (P<.001). Although the ceromer/FRC group showed the highest macroand micro-shear strength, the micro-shear strength was not significantly different from that of the base metal alloy groups. The base metal alloy substructure groups showed the lowest mean macro-shear strength. However, the gold alloy substructure group exhibited the least micro-shear strength. The micro-shear strength was higher than the macro-shear strength excluding the gold alloy substructure group. Adhesive failure was most frequent type of fracture in the ceromer specimens bonded to the gold alloys. Cohesive failure at the ceromer layer was more common in the base metals and FRC substructures. Conclusion. The Vectris substructure had higher shear strength than the other substructures. Although the shear strength of the ceromer bonded to the base metals was lower than that of the gold alloy, the micro-shear strength of the base metals were superior to that of the gold alloy.

• Journal of the Korean GEO-environmental Society
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• v.13 no.11
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• pp.51-60
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• 2012

In order to characterize the shear strength of the frozen sand for foundation design in cold region and prediction of adfreeze bond strength, many researchers developed test techniques and carried out many tests to analyze shear strength properties of the frozen sand for half a century. However, many studies for shear strength properties of the frozen sand have been carried out with limited circumstances, even though shear strength of the froze sand can be affected by various influence factors such as soil type, temperature conditions, and magnitude of normal stress. In this study, direct shear test equipment was used to analyze the shear strength characteristics of the frozen sand. Direct shear test equipment was designed for cold weather, and the direct shear tests were carried out inside of large-scaled low temperature chamber. Three soil types-two uniform sands and one well graded soil were used to analyze the shear strength of the frozen sand with three different temperature conditions and three different vertical confining pressures. In this research, a series of direct shear tests for shear strength of the frozen sand have been conducted to demonstrate the efficiency of effectiveness of the test equipment and low temperature chamber. This research also showed that shear strength of the froze sand increased with decreasing temperature condition, but the influence of vertical confining pressure was insignificant to the shear strength of the frozen sand.