• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.959-964
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• 2002

The purpose of this study is to establish flexural behavior of high-strength concrete by means of both theoretical approach and experimental analysis of beams in which confinement stirrups have been introduced into pure bending zone. The experiment was carried out on full-scale high-strength reinforced concrete beams whose compressive strengths are 400 and 700kgf/cm$^2$, and confined with rectangular closed stirrups. The test results are reviewed in terms of flexural capacity and ductility.

• Journal of the Korean Society of Safety
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• v.4 no.1
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• pp.47-58
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• 1989

This paper treats the vibration analysis of a simply supported rectangular plate stiffened with viscoelastic beams. The effect of viscoelastic beams on the vibration of the plate is analyzed by using Dirac delta function and the equation of motion can be expressed only one equation. The frequency equation is obtained by applying Laplace transformation. The effect of volumes, numben and aspect ratios of beam on the frequency of the plate is analyzed.

• Journal of Mechanical Science and Technology
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• v.17 no.8
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• pp.1156-1163
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• 2003

The pseudospectral method is applied to the analysis of in-plane free vibration of circularly curved Timoshenko beams. The analysis is based on the Chebyshev polynomials and the basis functions are chosen to satisfy the boundary conditions. Natural frequencies are calculated for curved beams of rectangular and circular cross sections under hinged-hinged, clamped-clamped and hinged-clamped end conditions and the results are compared with those by transfer matrix method. The present method gives good accuracy with only a limited number of collocation points.

• Computers and Concrete
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• v.20 no.2
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• pp.129-143
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• 2017

Seismic design of reinforced concrete (RC) structures requires a certain minimum level of flexural ductility. For example, Eurocode EN1998-1 directly specifies a minimum flexural ductility for RC beams, while Chinese code GB50011 limits the equivalent rectangular stress block depth ratio at peak resisting moment to achieve a certain nominal minimum flexural ductility indirectly. Although confinement is effective in improving the ductility of RC beams, most design codes do not provide any guidelines due to the lack of a suitable theory. In this study, the confinement for desirable flexural ductility performance of both normal- and high-strength concrete beams is evaluated based on a rigorous full-range moment-curvature analysis. An effective strategy is proposed for flexural ductility design of RC beams taking into account confinement. The key parameters considered include the maximum difference of tension and compression reinforcement ratios, and maximum neutral axis depth ratio at peak resisting moment. Empirical formulae and tables are then developed to provide guidelines accordingly.

• Steel and Composite Structures
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• v.37 no.5
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• pp.605-620
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• 2020

An innovative Partially Precast Steel Reinforced Concrete (PPSRC) beam is presented in this paper. To study the shear behavior of PPSRC beams, static loading experiments were conducted on 10 specimens, including 4 T-beam specimens and 4 PPSRC inverted T-beam specimens together with 2 PPSRC rectangular section beams. In the tests, the shear behaviors of the PPSRC beams were emphasized. On the basis of the experiments, the failure mode and ultimate bearing capacity were thoroughly examined. The calculation methods for shear capacity are also presented in this paper. The analysis of mechanical behavior and the calculation methods presented can be used as a reference to design these innovative composite PPSRC beams and provide a significant foundation for further research.

• International Journal of Concrete Structures and Materials
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• v.7 no.4
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• pp.273-285
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• 2013

An experimental investigation was conducted to compare the shear strength of full-scale beams constructed with chemically-based, self-consolidating concrete (SCC) with conventional concrete (CC). This experimental program consisted of 16 rectangular beams (12 without shear reinforcing and 4 with shear reinforcing in the form of stirrups), 8 beams for each mix design. Additionally, three different longitudinal reinforcement ratios were evaluated within the test matrix. The beam specimens were tested under a simply supported four-point condition. The experimental shear strengths of the beams were compared with both the shear provisions of selected standards (U.S., Australia, Canada, Europe, and Japan) and a shear database of CC specimens. This comparison indicates that chemically-based SCC beams possess comparable shear strength as CC beams.

• Structural Engineering and Mechanics
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• v.45 no.2
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• pp.169-182
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• 2013

The mechanical behavior of rectangular foundation plates with perimetric beams and internal stiffening beams of the plate is herein analyzed, taking the foundation design into account. A series of dimensionless parameters related to the geometry of the studied elements were defined. In order to generalize the problem statement, an initial settlements was considered. A numeric procedure was developed for the resolution by means of the Finite Differences Method that takes into account the stiffness of the plate, the perimetric and internal plate beams and the soil reaction module. Iterative algorithms were employed which, for each of the analyzed cases, made it possible to find displacements and reaction percentages taken by the plate and those that discharge directly into the perimetric beams, practically without affecting the plate. To enhance its mechanical behavior the internal stiffening beams were prestressed and the results obtained with and without prestressing were compared. This analysis was made considering the load conditions and the soil reaction module constant.

• Journal of the Korea institute for structural maintenance and inspection
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• v.6 no.1
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• pp.119-129
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• 2002

Reinforced concrete haunched beams have been used for enhancement of shear resistance of beams to avoid the stress concentration. But American and British codes do not give my formula for the design of haunched beams. The purpose of this research is to experimentally investigate the shear failure of reinforced concrete punched beams for various haunch inclinations and shear span-to-depth ratios. The experimental results showed that even though shear behavior of haunched beam were similar to that of resembled rectangular beams, shear span-to-depth ratios and inclinations of haunch had effects on shear cracking strength.

• Land and Housing Review
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• v.2 no.4
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• pp.471-477
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• 2011

This paper will describe the experimental results on the shear behaviors of reinforced concrete (RC) beam with recycled coarse aggregate (RCA). The primary objective of this research is to evaluate the influences of different RCA replacement percentage (i.e, 0%, 30%, 60%, and 100%) on the shear performance of reinforced concrete beams without shear reinforcement. Eight large-scale RC beams without shear reinforcement were manufactured and tested to shear failure. All had a rectangular cross-section with 400mm width ${\times}$ 600mm depth and 6000mm length, and were tested with a shear span-to-depth of 5.1. The results showed that the deflection and shear strength were little affected by the different RCA replacement percentage. Actual shear strength of each RCA beam was compared with the shear strength predicted using the provisions of ACI 318 code and Zsutty'e equation for shear design of RC beams. ACI 318 code predicted the shear strength of RCA reinforced concrete beams well.

• International Journal of Concrete Structures and Materials
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• v.10 no.2
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• pp.177-188
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• 2016

One of the primary concerns about the design aspects is that how to deal with the shear reinforcement in the ultra-high performance fiber reinforced concrete (UHPFRC) beam. This study aims to investigate the shear behavior of UHPFRC rectangular cross sectional beams with fiber volume fraction of 1.5 % considering a spacing of shear reinforcement. Shear tests for simply supported UHPFRC beams were performed. Test results showed that the steel fibers substantially improved of the shear resistance of the UHPFRC beams. Also, shear reinforcement had a synergetic effect on enhancement of ductility. Even though the spacing of shear reinforcement exceeds the spacing limit recommended by current design codes (ACI 318-14), shear strength of UHPFRC beam was noticeably greater than current design codes. Therefore, the spacing limit of 0.75d can be allowed for UHPFRC beams.