scholarly journals Creep Characteristics Of Concrete Used In Long-Span Arch Bridge

2019 ◽  
Vol 14 (1) ◽  
pp. 18-36 ◽  
Author(s):  
Yongbao Wang ◽  
Renda Zhao ◽  
Yi Jia ◽  
Ping Liao

The reinforced concrete arch bridge with concrete-filled steel tubular stiffened skeleton is extensively used in the mountainous area of southwest China due to their long span and high stability. Beibanjiang Bridge located in Shanghai- Kunming high-speed railway, which had a record span of 445 m, has recently been completed in 2016. However, concrete creep and shrinkage have pronounced effects on the long-term deflection and stress redistribution of this bridge. Several concrete creep and shrinkage specimens in the natural environment were made to predict the long-term behaviour of this bridge accurately. They were used to measure the concrete creep and shrinkage of the core concrete and surrounding concrete used in the arch bridge. The test results were compared to ACI209 R-92 Prediction of Creep, Shrinkage and Temperature Effects in Concrete Structures model, 1990 CEB-FIP Model Code 1990: Design Code model, fib Model Code for Concrete Structures 2010 model and Creep and Shrinkage Prediction Model for Analysis and Design of Concrete Structures-Model B3. Based on the numerical fitting method, the fib Model Code for Concrete Structures 2010 model was modified to suit the concrete creep and shrinkage experimental results. Then, the modified fib Model Code for Concrete Structures 2010 model was used to predict the timedependent behaviour of a concrete arch bridge.

2019 ◽  
Vol 14 (2) ◽  
pp. 227-248
Author(s):  
Yongbao Wang ◽  
Renda Zhao ◽  
Yi Jia ◽  
Ping Liao

This paper continues the previous study on clarifying the time-dependent behaviour of Beipanjiang Bridge ‒ a reinforced concrete arch bridge with concrete-filled steel tubular stiffened skeleton. The obtained prediction models and the Finite Element Models were used to simulate the long-term behaviour and stress redistribution of the concrete arch bridge. Three-dimensional beam elements simulated the stiffened skeleton and surrounding concrete. Then, a parameters study was carried out to analyse the time-dependent behaviour of the arch bridge influenced by different concrete creep and shrinkage models. The simulation results demonstrate that concrete creep and shrinkage have a significant influence on the time-dependent behaviour of the concrete arch bridge. After the bridge completion, the Comite Euro-International du Beton mean deviation of displacements obtained by 1990 CEBFIP Model Code: Design Code model and fib Model Code for Concrete Structures 2010 model are 3.4%, 31.9% larger than the results predicted by the modified fib Model Code for Concrete Structures 2010 model. The stresses between the steel and the concrete redistribute with time because of the concrete long-term effect. The steel will yield if the fib Model Code for Concrete Structures 2010 model is used in the analysis. The stresses in a different part of the surrounding concrete are non-uniformly distributed.


Author(s):  
Charles J. Oswald

Measurements made on a long span reinforced concrete arch culvert under 7.3 m (24 ft) of silty clay backfill were compared with results from finite-element analyses of the soil-structure system using the CANDE finite-element code. The culvert strains and deflections and the soil pressure on the culvert were measured during construction and during the following 2.5 years at three instrumented cross sections. The CANDE program was modified to account for the effects of concrete creep and shrinkage strains after it was noted that the measured postconstruction culvert deflection and strains increased significantly whereas the measured soil pressure on the culvert remained relatively constant. Good agreement was generally obtained between measured and calculated values of the culvert strain and deflection and the soil pressure during the entire monitoring period after the code was modified.


2013 ◽  
Vol 351-352 ◽  
pp. 1061-1065
Author(s):  
Shi Bo Zhang

This paper presents a model test research on long-term deflection of prestressed steel-concrete composite beams caused by creep and shrinkage effects of concrete. The model is designed based on a 20.8m length segment of a service composite beam bridge in Guangzhou. Geometric scale between the model and prototype is 1:8. Long-term deflection of the test model was obtained through 300 days of uninterrupted test. In addition, using the CEB-FIP (1990) criterion, effective modulus of concrete was calculated considering the effect of the concrete creep and shrinkage. Uniform the effective modulus of concrete to the modulus of steel, the value of structures time varying stiffness was calculated with single material theory and the relationship between stiffness and deflection by introducing stiffness adjustment coefficients was established, then the value of deflection changing with time was calculated.


2013 ◽  
Vol 95 (1) ◽  
pp. 64-75
Author(s):  
Rudolf Urban ◽  
Martin Štroner

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.


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