• Smart Structures and Systems
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• 제22권1호
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• pp.13-25
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• 2018

Pedro $G{\acute{o}}mez$ Bosque footbridge is a slender and lightweight structure that creates a pedestrian link over the Pisuerga River, Valladolid, Spain. This footbridge is a singular stress ribbon structure with one span of 85 m consisting on a steel plate and precast concrete slabs laying on it. Rubber pavement and a railing made of stainless steel and glass complete the footbridge. Because of its lively dynamics, prone to oscillate, a simple and affordable structural health monitoring system was installed in order to continuously evaluate its structural serviceability and to estimate its modal parameters. Once certain problems (conditioning and 3D orientation of the triaxial accelerometers) are overcome, the monitoring system is validated by comparison with a general purpose laboratory portable analyzer. Representative data is presented, including acceleration magnitudes and modal estimates. The evolution of these parameters has been analysed over one-year time.

• 콘크리트학회논문집
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• 제24권4호
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• pp.491-498
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• 2012

이 연구는 시멘트 콘크리트 포장의 보수나 프리캐스트 제품용으로 사용되는 UP-MMA 폴리머 콘크리트의 경화수축, 열팽창계수 및 탄성계수에 대한 연구이다. 이를 위해 UP-MMA비, SRA 첨가량, 시험온도 등을 변수로 하여 경화수축 시험과 UP-MMA비에 따른 열팽창과 압축응력-변형률에 대하여 시험을 실시하였다. 그 결과 경화수축은 29.2~$82.6{\times}10^{-4}$으로 UP 비율과 시험온도에 큰 영향을 받는 것으로 나타났다. 그리고 열팽창계수는 21.6~$31.2{\times}10^{-6}/^{\circ}C$, 탄성계수는 2.8~$3.3{\times}10^4MPa$, 극한변형률은 0.00381~0.00418이었으며, 이는 UP-MMA비에 크게 영향을 받는 것으로 나타났다. 이러한 결과들은 UP-MMA 폴리머 콘크리트의 적용을 위한 설계에 중요한 기초자료로 이용될 수 있을 것이다.

• 한국도로학회논문집
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• 제17권6호
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• pp.37-45
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• 2015

PURPOSES : The purpose of this study is to validate the design criteria of the concrete modular road system, which is a new semi-bridge-type concept road, through a comparison of numerical analysis results and actual loading test results under static axial loads. METHODS : To design the semi-bridge-type modular road, both the bridge design code and the concrete structural design code were adopted. The standard truck load (KL-510) was applied as the major traffic vehicle for the design loading condition. The dimension of the modular slab was designed in consideration of self-weight, axial load, environmental load, and combined loads, with ultimate limit state coefficients. The ANSYS APDL (2010) program was used for case studies of center and edge loading, and the analysis results were compared with the actual mock-up test results. RESULTS : A full-scale mock-up test was successfully conducted. The maximum longitudinal steel strains were measured as about 35 and 83.5 micro-strain (within elastic range) at center and edge loading locations, respectively, under a 100 kN dual-wheel loading condition by accelerating pavement tester. CONCLUSIONS : Based on the results of the comparison between the numerical analysis and the full-scale test, the maximum converted stress range at the edge location is 32~51% of the required standard flexural strength under the two times over-weight loading condition. In the case of edge loading, the maximum converted stresses from the Westergaard equation, the ANSYS APDL analysis, and the mock-up test are 1.95, 1.7, and 2.3 times of that of the center loading case, respectively. The primary reason for this difference is related to the assumption of the boundary conditions of the vertical connection between the slab module and the crossbeam module. Even though more research is required to fully define the boundary conditions, the proposed design criteria for the concrete modular road finally seems to be reasonable.