• Title/Summary/Keyword: road bridge

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A study of deterioration of reinforced concrete beams under various forms of simulated acid rain attack in the laboratory

  • Fan, Yingfang;Hu, Zhiqiang;Luan, Haiyang;Wang, Dawei;Chen, An
    • Structural Engineering and Mechanics
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    • v.52 no.1
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    • pp.35-49
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    • 2014
  • This paper studies the behaviour of deteriorated reinforced concrete (RC) beams attacked by various forms of simulated acid rain. An artificial rainfall simulator was firstly designed and evaluated. Eleven RC beams ($120mm{\times}200mm{\times}1800mm$) were then constructed in the laboratory. Among them, one was acting as a reference beam and the others were subjected to three accelerated corrosion methods, including immersion, wetting-drying, and artificial rainfall methods, to simulate the attack of real acid rain. Acid solutions with pH levels of 1.5 and 2.5 were considered. Next, ultrasonic, scanning electron microscopy (SEM), dynamic, and three-point bending tests were performed to investigate the mechanical properties of concrete and flexural behaviour of the RC beams. It can be concluded that the designed artificial simulator can be effectively used to simulate the real acid rainfall. Both the immersion and wetting-drying methods magnify the effects of the real acid rainfall on the RC beams.

Study on the Noise Characteristics of Bridge Deck Pavements in Seoul Inner Ring Road (서울시 내부순환도로 교면포장 형식에 따른 소음특성 연구)

  • Lee, Sang-Yum;Jin, Jung-Hoon;Mun, Sung-Ho;Moon, Hak-Ryong
    • International Journal of Highway Engineering
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    • v.14 no.2
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    • pp.19-28
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    • 2012
  • A measuring technique for tire-pavement interaction noise that uses a proposed noble close proximity(NCPX) method, which has been proofed in terms of the reliability and consistency of interaction noise measurement through several researches, equipped with surface microphones has been adopted in order to perform bridge deck pavement noise evaluations on four different pavement surfaces. Through field testing measurement of bridge deck pavement in Seoul inner ring road, the appropriate noise-measuring procedures have been used for evaluating the noise characteristics of four different surfaces. Measuring results show that tire-pavement noise levels vary depending on the surface types and vehicle speeds. Furthermore, the different characteristics of tire-pavement interaction noise can be found before and after the new surface construction of bridge deck pavements in terms of the 1/3 octave band analysis of vehicle speed.

Economic Analysis of Concrete Panel Replacement of PSC Bridge with Embedded Demountable Shear Connector (매립형 분리식 전단연결재를 적용한 PSC교 콘크리트 바닥판 교체공사의 경제성 분석)

  • Soon-Hwan, Lee;Jong-Eon, Kim;Jae-Gyu, Kim;Se-Hyun, Park;Dae-Sung, Jung
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.10 no.4
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    • pp.376-385
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    • 2022
  • The embedded demountable shear connector was developed in preparation for replacement works due to deterioration and damage to the bridge panel of the PSC girder bridge which is a road infrastructure directly related to the safety and convenience of the people. The demountable shear connector minimizes crushing works in the demolition process of the panel, and it is easy to re-construct the shear connector for replacement work. The economic feasibility of the PSC girder bridge using the embedded demountable shear connector compared to the existing construction method was analyzed from the perspective of road users (people) by calculating and comparing the cost of road users caused by traffic blocking during each construction method.

A Study on the Dynamic Response of Steel Highway Bridges Using 3-D Vehicle Model (3차원(次元) 차량(車輛)모델을 사용(使用)한 강도로교(鋼道路橋)의 동적응답(動的應答) 관(關)한 연구(硏究))

  • Chung, Tae Ju;Park, Young Suk
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.14 no.5
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    • pp.1055-1067
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    • 1994
  • This paper is presented to perform linear dynamic analysis of bridges due to vehicle moving on bridges. The road surface roughness and bridge/vehicle interaction are also considered. The bridge and vehicle are modeled as 3-D bridge and vehicle model, respectively. The road surface roughness of the roadway and bridge decks are generated from power spectral density(PSD) function for good road. The PSD function proposed by C.J. Dodds and J.D. Robson is used to describe the road surface roughness for good road condition. The vehicles are modeled as two nonlinear vehicle model with 7-D.O.F of truck and 12-D.O.F of tractor-trailer and the equations of motion of the vehicles are derived using Lagrange's equation. The main girder and concrete deck are modeled as beam and shell element, respectively and rigid link is used between main girder and concrete deck. The equations of motion of the vehicles are solved by Newmark ${\beta}$ method and the equations of the motion of the bridges are solved by mode-superposition procedures. The validity of the proposed procedure is demonstrated by comparing the results with the experimental data reported by the AASHO Road Test. The comparison shows that the agreement between experiment and theory is quite satisfactory.

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Pollutant Contents with Particle Size Distribution in Bridge Road Drainage Sediment (교량도로 배수받이 퇴적물질의 입경별 오염물질 함량)

  • Lee, Jun-Ho;Cho, Yong-Jin;Bang, Ki-Woong
    • Journal of Korean Society of Environmental Engineers
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    • v.29 no.12
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    • pp.1360-1365
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    • 2007
  • The purpose of this study is to present the basic data for nonpoint pollutant loads from bridge road drainage sediments using the results to analyze organic matter and heavy metals from the four bridge drainage sampling sites with sediments of different particle size ranges. The sediment sample was collected from the bridge road drainage and the masses of nine sediments fractions were obtained after drying the separated sediment in an over at $85^{\circ}C:>2,000{\mu}m$, $1,000\sim2,000{\mu}m$, $850\sim1,000{\mu}m$, $425\sim850{\mu}m$, $212\sim425{\mu}m$, $125\sim212{\mu}m$, $90\sim125{\mu}m$, $75\sim90{\mu}m$, $<75{\mu}m$. The sediment extract was analyzed water quality constituents, including chemical oxygen demand(COD), total nitrogen(T-N), total phosphorus(T-P), heavy metals and particle size distribution. The results indicate that most of particle size ranges of the bridge road sediments was $125\sim425{\mu}m$, and portion of $<75{\mu}m$ was low. But most of the pollutants are associated with the finer fractions of the load sediments. As the results of analysis, the range and average values of COD, T-N, T-P, Fe, Cu, Cr, and Pb were $177\sim198.8$ mg/kg(77.6 mg/kg), $23\sim200$ mg/kg(83 mg/kg), T-P $18\sim215$ mg/kg(129 mg/kg), and $1,508\sim5,612$ mg/kg(3,835 mg/kg), $9.2\sim69.3$ mg/kg(49 mg/kg), $19.1\sim662.2$ mg/kg(214 mg/kg), and $28.4\sim251.4$ mg/kg(114 mg/kg), respectively. The relationship between sediment size and pollutants concentration have an inverse proportion. The removal of road sediments with frequently could be reduced the significant nonpoint pollutant load, because of the bridge road sediment contains considerable micro-particles and heavy metals.

Plan and Design of Fan-Type Arch Railway Bridge (경사행거아치철도교의 계획과 설계)

  • 이충표;김종오;이훈희;이강진
    • Proceedings of the KSR Conference
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    • 2002.10a
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    • pp.672-677
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    • 2002
  • Railway bridge type has been mainly selected by a intersection of roads and rivers, and economy. Now a days, it is required that the bridge type is considered a harmony with circumstances, a beauty and an expression of symbol of regions because of the enlargement of bridge structures and the advance of people's consciousness level. So it is adopted arch bridge with fan type hanger for a outer beautiful sight and a symbol of development of regions as 80m intersection bridge of railway and former national road at pal hung bridge in jolla line lot 1. It is performed that an examination, a consultation, a design of member sections and a detail analysis of joint parts according to the basic design. It is also performed a dynamic analysis with design loads and train loads reflection on railway bridge characteristics and examined a safety and a propriety of design compare with a fatigue design and design rules.

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Amber Information Design to Keep Safety-Driving Under Road Structure at Local-Scale Geographic (국지지역 도로 기반 시설에서 안전운전을 위한 경보 정보 설계)

  • Park, Jung-Chan;Hong, Gyu- Jang
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.58 no.1
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    • pp.48-55
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    • 2009
  • In order to keep safe driving conditions under road networks, there are several formations such as road structure, road surface condition, traffic occupancy and supplement of an accurate information of traffic status ahead To support safe-driving on each road formation, each formation is supplied with various information to help the driver. However, in some cases like rapid status change at local-scale geography, traffic information systems often displays insufficient information because of the lack of information correlation. In order to accurately aware the driver, all road formation must be in sync. It is important to supply accurate information to the driver because this information directly impacts the drivers on the road. This paper discusses the amber information to keep the least safety driving over road formations including tunnels and bridges. This paper also will propose the informations for safe-driving conditions, information linkage on the road and rule-base safety information, as ITS technology, being displayed for all drivers under the worst weather conditions.

Treatment of Concrete Wastewater in Repair of Bridge Deck (교량 바닥판 보수공사에서 발생하는 콘크리트 폐수처리 방안)

  • Lee, Bong-Hak;Choi, Pan-Gil;Kim, Jung-Ki
    • Journal of Industrial Technology
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    • v.28 no.A
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    • pp.125-132
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    • 2008
  • As of 2003, construction waste has been produced at the level of 130,614.8 tons/day, in which the amount of waste concrete was 92,639.1 tons/day and accounted for about 66.4% of the amount of construction waste. Waste concrete is mainly produced in construction work and civil engineering work. Especially, road surface crushing method using a large amount of water requires thorough management of concrete wastewater. The aim of this study was to analyze water pollution due to concrete wastewater generated in repair of bridge deck using road surface crushing equipment and to suggest reasonable countermeasures for solve the problem. In this study, it was surveyed current conditions of produced concrete wastewater in bridge deck repair, analyzed physical features of concrete wastewater, expected effects of water pollution on inflow rivers if it is not treated, established treatment plan of water pollution by categories, and calculated capacity of each treatment process and required amount of necessary chemicals. As a result of sampling wastewater generated in field sites and testing it at a lab scale, it was revealed that the original wastewater was produced in removing concrete from bridge deck slabs using surface crushing equipment whose pH was 12.53, CODMn was 12.910mg/L, SS was 547.0mg/L, and other heavy metals were included in extremely small quantities.

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Evaluation of Structural Performance of RC Deck Slabs by High-Strength Concrete (고강도 콘크리트를 적용한 RC 바닥판의 정적 성능 평가)

  • Bae, Jae-Hyun;Hwang, Hoon-Hee;Park, Sung-Yong;Joh, Keun-Hee
    • Journal of the Korean Society of Safety
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    • v.31 no.3
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    • pp.89-95
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    • 2016
  • Lately, the high-strength concrete is often used to increase the lifespan of bridges. The benefits of using the high-strength concrete are that it increases the durability and strength. On the contrary, it reduces the cross-section of the bridges. This study conducted structural performance tests of the bridge deck slabs applying high-strength concrete. As result of the tests, specimens of bridge deck slabs were destroyed through punching shear. Moreover, the tests exposed that the high-strength concrete bridge deck slabs satisfy the flexural strength and the punching shear strength at ultimate limit state(ULS). Also, limiting deflection of the concrete fulfilled serviceability limit state(SLS) criteria. These results indicated that the bridge deck slabs designed by high-strength concrete were enough to secure the safety factor despite of its low thickness.