Long-term seismic performance of reinforced concrete bridges under steel reinforcement corrosion due to chloride attack

2013 ◽  
pp. n/a-n/a ◽  
Author(s):  
Yu-Chen Ou ◽  
Hong-Da Fan ◽  
Nguyen Dang Nguyen
Author(s):  
Tae-Hoon Kim

AbstractThis paper presents a nonlinear analysis procedure for the seismic performance assessment of deteriorated reinforced concrete bridges using a modified damage index. A finite-element analysis program, RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology), is used to analyze deteriorated two-span simply supported reinforced concrete bridges. The new nonlinear material models for deteriorated reinforced concrete behaviors were proposed, considering corrosion effects as shown in a reduction in reinforcement section and bond strength. A modified damage index aims to quantify the seismic performance level in deteriorated reinforced concrete bridges. Several parameters of two-span simply supported deteriorated reinforced concrete bridge have been studied to determine the seismic performance levels. The newly developed analytical method for assessing the seismic performance of deteriorated reinforced concrete bridges is verified by comparison with the experimental and analytical parameter results.


1999 ◽  
Vol 5 (S2) ◽  
pp. 826-827
Author(s):  
W.K. Collins ◽  
S.D. Cramer ◽  
B.S. Covino ◽  
R.D. Govier ◽  
G.R. Holcomb ◽  
...  

Microanalysis has proved crucial in developing thermal-sprayed metal coatings on the surface of reinforced concrete to serve as anodes in impressed current (ICCP) and galvanic (GCP) cathodic protection systems and in understanding their long-term performance. Corrosion of reinforcing bar in concrete bridges is the primary cause of structural deterioration in high chloride environments such as coastal locations and colder climates where roads are deiced with salt. Over 40 pet of more than 500,000 bridges surveyed in the U.S. are in need of repair or rehabilitation. Cathodic protections is the most effective method of mitigating the effects of corrosion due to chloride contaminated concrete. While a young technology, consumable thermal sprayed zinc anodes (see Figure 1 for a schematic of the process) totaling over 40,000 m2 (430,00 ft2) have been installed on the Oregon coast, primarily on the Depoe Bay, Yaquina Bay, and Cape Creek bridges.


2012 ◽  
Vol 5 (3) ◽  
pp. 388-419
Author(s):  
P. T. C. Mendes ◽  
M. L. T. Moreira ◽  
P. M. Pimenta

Most of the Brazilian bridges of federal road network are made of reinforced concrete and are more than 30 years old, with little information about the mechanical properties of their constitutive materials. Along the service life of these bridges much modification occurred on vehicles load and geometry and in design standard. Many of them show signs of concrete and steel deterioration and their stability conditions are unknown. With the aim of contributing to the structural evaluation of reinforced concrete bridges it was decided to analyze the stresses in reinforced concrete bridge sections to verify the effects due to reinforcement corrosion and variation of the concrete Young modulus on the stress distribution regarding several load patterns and cracking effects in a representative bridge of the Brazilian road network with different longitudinal reinforcement taxes and two concrete Young modulus, Ec and 0.5Ec, and with different percentage of reinforcement corrosion. The analysis considered two finite element models: frame and shell elements as well as solid elements. The results indicate that these variation effects are more significant in reinforcement bars than in concrete.


Author(s):  
J. J. LUCHKO ◽  
I. I. KARKHUT ◽  
I. B. KRAVETS

Purpose. The aim of the work is to summarize design errors, construction defects and shortcomings and bridge defects after long-term operation on the basis of real field studies and analysis of scientific and technical sources. Methodology. To achieve this goal, an inspection of scientific and technical sources and regulations on the technical condition of transport facilities in Ukraine was conducted. In particular, it is a bridge in the city of Khust, built in 2000 on the site destroyed by floods in 1998 and a monolithic frame-cantilever bridge on the highway Mukachevo-Rogatin km 92 +700, built in 2001 on the site of partially destroyed in March 2001. The authors also took part in the construction, testing for static and dynamic loads of six steel-reinforced concrete bridges in Kobiletska and Kosivska Polyana, which were erected in 2000 on the site of those destroyed by the 1998 flood, as well as overpasses and bridges of long-term operation, – this is the Beregovsky bridge in the city of Mukachevo and the overpass in the village of Vistova. The results of the analysis and synthesis of the above studies became the basis for establishing the corresponding design errors, defects and shortcomings in construction and shortcomings in the operation of bridges and overpasses. Results. The analysis of domestic and foreign scientific and technical sources regarding the technical condition of the constructed reinforced concrete, steel-reinforced concrete bridges and bridges and overpasses of long-term operation is carried out. The analysis and synthesis of the problems of ensuring the reliability and durability of transport structures in the conditions of their operation in the air, soil and water environment. It is established on real examples of design errors, defects and shortcomings in construction, shortcomings in operation. The possibility of restoring the bearing capacity using modern materials and technologies is shown. Scientific novelty. As a result of the analysis of transport structures, scientific and technical sources and a number of studies of reinforced concrete and steel-reinforced concrete structures of bridges built after the floods in 1998 and 2001 and bridges (overpasses) of long-term operation, it was possible to summarize the main reasons that significantly affect the degradation of the structures of these bridges and overpasses. The possibility of restoring their bearing capacity and durability using modern materials and technologies is shown. In particular, it was found that in addition to power factors, factors of the air, soil and water environment also significantly affect. Practical significance. On the basis of these data, and observing the indicated objects for 20 years, it was possible to generalize and establish design errors, defects and shortcomings in construction and shortcomings of long-term operation. This makes it possible to propose areas of theoretical and experimental research and calculation methods, to take them into account in the design and operation of such structures. In particular, on the basis of these data, a technique was created and tested on real objects, which makes it possible to significantly increase the durability and reliability of such structures, using modern materials and technologies for repair and restoration work.


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