In this study, the usage of cement amount is minimized to reduce CO2 emission and toxic effect to users for concrete mix design. The reduction of cement is achieved using quad-type admixture (GGBS, FA, Cement, Hwangtoh powder)used for concrete mix design. In order to apply the mix performed design to construction usage, material tests such as compressive strength, slump and pH tests are Preliminary experiment results showed that, the quad-type concrete showed feasibility of being used as a healthy and CO2 reducing construction material
Construction period is one of the most important factors which influence on cost and quality in nuclear power plant construction. As part of continued efforts for the competent reactor type, the construction improvements such as application of mechanical rebar splice, optimum lift height for concrete placement and enlargement of liner plate module in the reactor building wall are developed to minimize the construction period. This study referred to knowledge and experiences from APR+(Advanced Power Reactor Plus) technical development. The proposed method can be applied to the APR+ in the near future.
Shin Geo-Je Bridge needs new inspection holes to improve the accessibility for various maintenances. This study evaluated the maximum von mises stresses(SE) of the bottom flange when the inspection holes is made with an ellipse shape. The FEM analysis results show that it is reasonable the hole is installed near the inflection point of the girder from a structural safety point of view though additional cost for the inspection walkway
The specimen shall contain tohose anchorage components and bursting reinforcement which will be embedded in the structural concrete, and their arrangement has comply with the intended application and with the specification as per the ETAG013. Components shall randomly selected.
Hybrid coupled shear wall with steel coupling beam has often been used to resisting system of earthquake load and transverse load. This study addresses the strain characteristics of coupling beam in hybrid wall system.
According to 10CFR50.150, all applicants for new nuclear power plant designs after July 13, 2009
must perform a design-specific assessment of the effects on the facility of the impact of a large, commercial aircraft using realistic analyses. The purpose of the work described in this paper is to evaluate the safety of the APR+ nuclear power plant with respect to the impact by a large commercial aircraft using the missile-target interaction analysis method.
The objective of this study is to evaluate fatigue behavior of transverse connection of girder-type modular bridge. In order to evaluate fatigue behavior, a integral specimens and one segmental specimens were applied fatigue load ranging between 10% and 60% maximum static load with 200000 cycles. In order to test the serviceability, another segmental specimens was applied a fatigue load ranging between 10% and 100% service load with 2 million cycles. The results showed that the segmental specimens had enough safety and serviceability under fatigue load.
Reinforced concrete coupled shear wall systems in medium and high-rise construction, where RC beams couple two or more RC walls have been frequently used. The objective of this study is to investigate seismic behavior of coupled shear wall according to the replacement ratio of headed-bar.
To evaluate the flexural performance of composite precast concrete ribbed slabs, tests are conducted with the variables of dapped-end configurations, support conditions, and longitudinal reinforcements. As the result of the tests, the performance should be evaluated by experiments and analyses using STM(Strut-Tie Model) for the design of dapped-end members
Multiple strand cable should be installed by special method to achieve equivalent tensile force to each strand. The research group has developed special jacking system and verified experimentally. As a result, difference is below 2% bet. theoretical and experimental values.
The objective of this study is to investigate the influence of PVA Fiber on flexural yielding coupling beam. Test variable of this study is material type of coupling beam. Test results showed that coupling beam with PVA material experienced multiple micro craks.
This paper describes the flexural performance of concrete and strain-hardening cement based composite (SHCC) beams reinforced with normal and high-strength steel bar to evaluate the effect of reinforcing bar strength and cement composite type. The present investigation shows the potential of high-strength structure materials used of high-strength reinforcing bars with SHCC. And superior mitigation of crack-damage is observed reinforced SHCC beams than reinforced concrete beams
Generally deformation of wooden structures is larger than that of concrete and steel structures. We measured deformation of traditional Korean-style houses periodically and analyzed their deformation patterns. We expect that this study can help to reveal causes of long-term deformation of traditional Korean-style houses.
Recently, study on the application of sustainable materials to building and civil structure fields has been increased. Especially, the usage of aluminum alloys can improve durability of structures due to it’s high corrosion resistance. In this study, to investigate the ultimate behaviors such as ultimate strength and fracture mode of single shear bolted connections with aluminum alloys (7075-T6), experiments were conducted. Main variables are bolt arrangement and end distance parallel to the direction of load. As a result, the specimens failed by shear out fracture and block shear fracture and also the specimens with long end distance were accompanied by curling (out of plane deformation). The curling led to reduction of ultimate strength or rigidity. Futhermore, pattern of strain distribution was investigated according to curling occurrence.
In this study, we suggest the process that can effectively evaluate safety and serviceability of purlin members of new traditional Korean-style house. It is composed of three parts, that is, input, structurecalculation, and structure-evaluation part. We expect that this suggested process can help structural engineers to secure safety and serviceability of new traditional Korean-style house.
In this paper, we analyze the lateral behavior of a jacket substructure for offshore wind turbine embedded in sandy soil, and identify the differences of results by soil modeling methods that are fixed end method, coefficient of subgrade reaction method, coupled matrix method, and p-y, t-z, q-z curve methods.
This study was conducted to examine for serviceability of GFRP for application of Slip-Form. As a result, Flexure performance of GFRP module is similar to steel material. And accumulated wear volume of GFRP module is 0.02% when sliding distance reaches at 1000m.
In the construction of nuclear power plants using massive walls in Korea, the use of high-strength re-bars for shear design is necessary to enhance the constructability and economy. In the present study, low-rise walls(aspect ratio = 1.0) with 550MPa grade bars, were tested under cyclic loading to investigate shear capacity and deformation capacity of the walls. The results were compared with the performance of walls with grade 420 bars and predictions by current design code. The test results showed that ACI 349 underestimated the shear strength of the walls with 550 MPa grade bars. This result indicated that the ACI 349 predictions can be safely used for the earthquake design of the low-rise walls (aspect ratio =1.0) with 550 MPa grade bars.
Numerical scheme of predicting large deflection of RC column structures is discussed by developing the algorithm of equivalent lateral loading system based on theorem of virtual work.
To evaluate the traffic safety of PSC box bridge for high running speed up to 450km/h of KTX, a dynamic analysis of rotation spectrum on the centre of vehicle is needed concurrently with existing design specifications. All directions of rotation spectrum are considered to analyze the dynamic structural behaviors of PSC bridges as well as harmonic running movements of KTX due to three mass; a cargo body, front/rear bogies and four wheel axises connected with two suspensions. KTX power train is modeled by 38 degree-of -freedom ; 6 degree-of-freedom for body and bogies, and 5 degree-of-freedom for wheel axises. The rotation spectrum of KTX resulted in the analysis will be focused on the design specification of KTX running on the bridge, for increasing its speed as a new evaluation standards of traffic safety