Long-term performance of prestressed concrete bridges under the intertwined effects of concrete damage, static creep and traffic-induced cyclic creep

2016 ◽  
Vol 127 ◽  
pp. 510-524 ◽  
Author(s):  
Teng Tong ◽  
Zhao Liu ◽  
Jie Zhang ◽  
Qiang Yu
Keyword(s):  
Prestressed Concrete ◽  
Cyclic Creep ◽  
Concrete Bridges ◽  
Prestressed Concrete Bridges ◽  
Static Creep ◽  
Concrete Damage ◽  
Long Term Performance ◽  
Term Performance

The investigation and proposed rehabilitation of the Tsing Yi South Bridge, Hong Kong

1988 ◽  
Vol 15 (2) ◽  
pp. 190-198
Author(s):  
A. S. Beard ◽  
H. S. S. Tung
Keyword(s):  
Prestressed Concrete ◽  
Load Testing ◽  
Concrete Core ◽  
Box Girder ◽  
Expansion Joints ◽  
Radiographic Inspection ◽  
Core Extraction ◽  
Long Term Performance ◽  
Term Performance

The Tsing Yi South Bridge was constructed in the early 1970s to provide access between Tsing Yi Island and the mainland at Kwai Chung. It has a prestressed concrete box girder superstructure consisting of five independent units which are monolithic with their piers and have expansion joints at the mid-span shear hinges and the abutments. During routine maintenance it was found that the superstructure cantilevers were deflecting excessively, and consequently a thorough inspection and appraisal were commissioned. These included a complete visual inspection, concrete core extraction, radiographic inspection of prestressing tendons and a programme of load testing. The bridge was also reanalyzed to check its long-term performance. Subsequently, a rehabilitation scheme was designed to recover part of the deflection. This involved the introduction of additional prestress near the box girder's top flange. Key words: prestressed concrete, structural assessment, creep, shrinkage, radiographic inspection, rehabilitation, external prestressing.

scholarly journals Long-term Deflections in Balanced Cantilever Prestressed Concrete Bridges

2009 ◽  
Vol 4 (1) ◽  
pp. 22
Author(s):  
Eltayeb Hassan Onsa ◽  
Elsafi Mohamed Adam ◽  
Abdalla Khogali Ahmed ◽  
Mohamed Elmontasir Elbagir
Keyword(s):  
Prestressed Concrete ◽  
Concrete Bridges ◽  
Live Load ◽  
Prestressed Concrete Bridges ◽  
Prestressing Force ◽  
Load Tests ◽  
The Moment ◽  
Aashto Lrfd ◽  
Made In

Long-term deflections in balanced cantilever prestressed concrete bridges are reviewed. Burri and Shambat Bridges are taken as cases study to calculate long-term deflection. The two bridges were constructed at Khartoum State in the years 1972 and 1962, respectively. Due to the shortage of the basic data regarding the two bridges the AASHTO-LRFD is used to estimate and calculate the missing data in the two bridges. The Moment Area method is used to calculate the long-term deflections due to the dead load, live load and prestressing force. The calculated long-term deflections are compared with measured live load deflections obtained from load tests made by a Chinese contractor requested to evaluate the two bridges. Remarkable differences between theoretical and measured deflection at the end of cantilevers are encountered. The differences are probably due to the basic assumptions made in the formulations of deflection calculations. Some adjustments in the long-term deflection formulae are suggested to bring the calculated deflections in compatibility with measured ones.

scholarly journals MEASUREMENT OF DEFLECTION LINE ON BRIDGES

2013 ◽  
Vol 95 (1) ◽  
pp. 64-75
Author(s):  
Rudolf Urban ◽  
Martin Štroner
Keyword(s):  
Prestressed Concrete ◽  
Concrete Structures ◽  
Measurement Procedure ◽  
Concrete Bridges ◽  
Prediction Methods ◽  
Prestressed Concrete Bridges ◽  
Long Span ◽  
Bridge Structures

Abstract Prestressed concrete bridges are very sensitive to the increase in long-term deflections. Reliable forecasts of deflections of bridge structures during construction and durability are crucial for achieving good durability. The main results of measurements are the changes of the deflection line of the bridge structures, which places special demands on the measurement procedure. Results from measurements are very useful for the improvement of mathematical prediction methods of behaviour of long span prestressed concrete structures.

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

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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