Literature Reviews and Summary of Concrete Bridge Seamless Broaden Technology

When the bridges broaden with seamless technology, there are differences between the existing bridge and the new bridge in design, construction and service. Because of concrete creep and shrinkage, temperature effect and prestress loss, there are stress defects in the seam, which will affect the service and safety. The current methods for the seam in foreign and domestic, such as plant steel and semi-rigid connection method are passive measures based on structure exiting state, which cannot ensure the long-term performance of the seam.

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Parsing on the Processing Methods of Seamline for Concrete Bridgewith Seamless Broaden Technology

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.587-589.1581 ◽

2014 ◽

Vol 587-589 ◽

pp. 1581-1585 ◽

Cited By ~ 2

Author(s):

Fang Yuan Li ◽

Xiao Shuai Guo

Keyword(s):

Driving Safety ◽

Prestress Loss ◽

Shrinkage Temperature ◽

Long Term Effect ◽

Rigid Connection ◽

The Difference ◽

Long Term Performance ◽

Term Performance ◽

Creep And Shrinkage

In view of the difference in design, construction and the usage of the old and the new bridges, there are always stress defects in seamline because of the concrete creep and shrinkage, temperature effect and prestress loss, which seriously affect the service and driving safety. The current ways in foreign and domestic, such as plant steel and semi-rigid connection method, are passive processing based on structure, can’t ensure the long-term performance. According to the three direction stress existing in the seamline, this paper decomposes the material contribution and structure influence, putting forward respectively using material and structure to overcome the adverse situation, using material to remove partial long-term effect, and through the sensitivity analysis of related parameters, to make the structure bearing the rest adverse effect, ensuring the long-term performance of seamline. The relevant conclusion can provide reference for the design and construction of the concrete bridge seamline.

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Analysis of Long-Term Prestress Loss in Prestressed Concrete (PC) Structures Using Fiber Bragg Grating (FBG) Sensor-Embedded PC Strands

Applied Sciences ◽

10.3390/app112412153 ◽

2021 ◽

Vol 11 (24) ◽

pp. 12153

Author(s):

Sung-Tae Kim ◽

Young-Soo Park ◽

Chul-Hwan Yoo ◽

Soobong Shin ◽

Young-Hwan Park

Keyword(s):

Optical Fiber ◽

Prestressed Concrete ◽

Optical Fiber Sensor ◽

Fiber Sensor ◽

Prestress Loss ◽

Fbg Sensor ◽

Embedded Pc ◽

Long Term Performance ◽

Term Performance

This study aims to develop a prestressed concrete steel (PC) strand with an embedded optical Fiber Bragg Grating (FBG) sensor, which has been developed by the Korea Institute of Civil Engineering and Building Technology since 2013. This new strand is manufactured by replacing the steel core of the normal PC strand with a carbon-fiber-reinforced polymer (CFRP) rod with excellent tensile strength and durability. Because this new strand is manufactured using the pultrusion method, which is a composite material manufacturing process, with an optical fiber sensor embedded in the inner center of the CFRP Rod, it ensures full composite action as well as proper function of the sensor. In this study, a creep test for maintaining a constant load and a relaxation test for maintaining a constant displacement were performed on the proposed sensor-type PC strand. Each of the two tests was conducted for more than 1000 h, and the long-term performance verification of the sensor-type PC strand was only completed by comparing the performance with that of a normal PC strand. The test specimens were fabricated by applying an optical fiber sensor-embedded PC strand, which had undergone long-term performance verification tests, to a reinforced concrete beam. Depending on whether grout was injected in the duct, the specimens were classified into composite and non-composite specimens. A hydraulic jack was used to prestress the fabricated beam specimens, and the long-term change in the prestress force was observed for more than 1600 days using the embedded optical fiber sensor. The experimental results were compared with the analytical results to determine the long-term prestress loss obtained through finite-element analysis based on various international standards.

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