• Journal of the Korean Wood Science and Technology
• /
• v.48 no.6
• /
• pp.791-806
• /
• 2020

In this study, a block shear strength test was conducted to compare and analyze the strength and failure mode on the glued laminated timber, CLT, and Ply-lam CLT, which are mainly used for the construction of wood construction as engineering wood. Through this, the Ply-lam CLT manufacturing conditions for optimum production, such as the type of lamina, plywood, adhesive, and layer composition, were investigated. The results are as follow. Through block shear strength test, it showed high strength in the order of glued laminated timber, Ply-lam CLT and CLT. In particular, the shear strength of Ply-lam CLT, which is made of a composite structure of larch plywood and larch lamina, passed 7.1 N/㎟, which is a Korean industrial standards for block shear strength of structural glued laminated timber. In addition, in this study, there was no different in shear strength according to the adhesive type used for glulam, CLT, and Ply-lam CLT adhesion. However, in the case of Ply-lam CLT, the difference in shear strength of Ply-lam CLT was shown according to the type of lamina and plywood. The results showed high strength in the order of Larix kaempferi > Mixed light hardwood ≒ Pinus densiflora, sieb, et, Zucc plywood. The optimal configuration of Ply-lam CLT is when larch plywood and larch lamina are used, and it is decided that the adhesive can be used by selecting PRF and PUR according to the application. The results of block shear strength failure mode by type of wood based materials were analyzed. The failure mode showed shear parallel-to-grain for glulam, rolling shear for CLT, and shear parallel-to-grain and rolling for ply-lam CLT. This is closely related to shear strength results and is decided to indicate higher shear strength in Ply-lam CLT than in CLT due to rolling shear.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2004.11a
• /
• pp.357-360
• /
• 2004

Estimation of deformation capacity of non-flexural reinforced concrete members is proposed using basic concepts of limit analysis and the virtual work method. This new approach starts with construction of admissible stress field as for an equilibrium set. Failure mechanisms compatible with admissible stress fields are postulated as for displacement set. It is assumed that the ultimate deformations as result of failure mechanisms are controlled by ultimate strain of concrete in compression. The derived formula for deformability of deep beams in shear shows reasonable range of ultimate displacement.

• Advances in concrete construction
• /
• v.15 no.5
• /
• pp.349-358
• /
• 2023

Aim of this work is investigating effect of thickness-stretching formulation on the quasi three-dimensional analysis of micro plate based on a thickness-stretched and shear deformable model through principle of virtual work and micro-scale dependent constitutive relations. Governing differential equations are derived in terms of five unknown functions and the analytical solution is derived using Navier's technique. To explore effect of thickness stretching model on the static results, a comparison between the results with and without thickness stretching effect is presented.

• Journal of the Korea Concrete Institute
• /
• v.28 no.4
• /
• pp.473-480
• /
• 2016

The purpose of this study is to provide analytical method to reasonably evaluate the complicated failure behaviors of shear friction of reinforced concrete shear wall specimens using grade 500 MPa high-strength bars. A total of 16 test specimens with a variety of variables such as aspect ratio, friction coefficient of interface in construction joint, reinforcement details, reinforcement ratio in each direction, material properties were selected and the analysis was performed by using a non-linear finite element analysis program (RCAHEST) applying the modified shear friction constitutive equation in interface based on the concrete design code (KCI, 2012) and CEB-FIP Model code 2010. The mean and coefficient of variation for maximum load from the experiment and analysis results was predicted 1.04 and 17% respectively and properly evaluated failure mode and overall behavior characteristic until failure occur. Based on the results, the analysis program that was applied modified shear friction constitutive equation is judged as having a relatively high reliability for the analysis results.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.20 no.3
• /
• pp.1-9
• /
• 2016

The purpose of this study is to examine the shear strength and structural performance of DH-Beams. The DH-Beam construction method uses thin steel plates as form-works and structural elements. Steel plates and rebars for DH-Beams were prefabricated at factory and then erected before casting concrete at construction sites. In this study, the contribution of steel plates to the shear strength of DH-Beam was evaluated since the plates were expected to work as reinforcements. Five test specimens were made for experimental and analytical studies. They consisted of two DH-Beams for the positive loading test and two DH-Beams for the negative loading test and a RC beam for the comparison purpose. Test results on DH-Beams were compared with design equations and the RC beam test result. It was proven that DH-Beams demonstrated the good shear behavior showing sufficient strengths and deformation capacities. Nonlinear analyses with test specimens were also used to evaluate the contribution of DH plates to strengths. Analytical models included various cases such as beams with lateral plates only or beams without any plates. These analyses also showed that steel plates can contribute to the enhancement of shear strength of DH-Beams. Based on experimental and analytical studies, it was concluded that steel plates of DH-Beams can be used as good shear reinforcements.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2005.09b
• /
• pp.938-939
• /
• 2005

• Journal of the Korean GEO-environmental Society
• /
• v.11 no.9
• /
• pp.5-14
• /
• 2010

This study was aimed to suggest reliable information of shear strength characteristics due to change of saturation in the landfills or slopes during rainfall infiltration. According to the Mohr-Coulomb failure criteria, the characteristics of shear strength due to change of saturation were analyzed for the weathered residual soils which were sampled in the road construction site of Daejeon city. From the direct shear strength tests, the cohesions and the shear resistance angles were showed maximum values in the condition of optimum moisture content, and then decreased in the condition of wet side compaction. In this study, the cohesions were decreased more than 50% according to increasing saturation by infiltration for the compaction soils. But the reductions of the shear resistance angles were about $1{\sim}2^{\circ}$ which was small value, and thus the changes of the saturation were not nearly influenced the shear resistance angle. The influences of the saturation were seemed to very small for the residual strength parameters according to Mohr-Coulomb failure criteria.

• Journal of the Korea Concrete Institute
• /
• v.17 no.3 s.87
• /
• pp.343-351
• /
• 2005

This study developed a shear strength prediction model of FRP strengthened reinforced concrete beams in shear. The primary design parameters were shear crack angle and shear span to depth ratio of FRP reinforcement. Of primary concern In the suggested model was the FRP debonding failure, which Is a typical fracture mode of RC beams strengthened with FRP, The proposed model used a crack sliding model based on modified plasticity theory. To address the effect of the shear span to depth ratio, the arch action was considered in the proposed model. The proposed model was applied to RC beams strengthened with FRP. The results showed that the proposed model agree with test results.

• Structural Engineering and Mechanics
• /
• v.76 no.1
• /
• pp.83-99
• /
• 2020

Shear walls are structural members in buildings that are used extensively in reinforced concrete frame buildings, and almost exclusively in the UK, regardless of whether or not they are actually required. In recent years, the UK construction industry, led by the Concrete Centre, has questioned the need for such structural elements in low to mid-rise reinforced concrete frame buildings. In this context, a typical modern, 5-storey residential building is studied, and its existing shear walls are replaced with columns as used elsewhere in the building. The aim is to investigate the impact of several design variables, including concrete grade, column size, column shape and slab thickness, on the building's structural performance, considering two punching shear limits (V_Ed/V_Rd,c), lateral drift and accelerations, to evaluate its maximum possible height under wind actions without the inclusion of shear walls. To facilitate this study, a numerical model has been developed using the ETABS software. The results demonstrate that the building examined does not require shear walls in the design and has no lateral displacement or acceleration issues. In fact, with further analysis, it is shown that a similar building could be constructed up to 13 and 16 storeys high for 2 and 2.5 punching shear ratios (V_Ed/V_Rd,c), respectively, with adequate serviceability and strength, without the need for shear walls, albeit with thicker columns.

• Land and Housing Review
• /
• v.4 no.4
• /
• pp.371-382
• /
• 2013

This study performs an experimental investigation to evaluate the behavior of RC flat plate interior joints specimens. Three 60 percent scale Flat Plate interior specimens assemblies representing a portion of a Flat Plate Apartment Structural System subjected to simulated seismic loading (unbalanced moments) under constant axial load were tested, including one specimens with ordinary shear reinforcement and two specimens with folded bend type shear reinforcement. Test results are shown that (1) the design code KBC 2009 is accurate estimate the behavior of specimens. (2) Two types shear reinforcement have a similar structural behavior, but construction work of rebar with folded bend type shear reinforcement is easier than that of ordinary shear reinforcement. (3) In moderate seismic region, RC Flat Plate interior joint with folded bend type shear reinforcement is apply to structural design of Flat Plate.