Steel Reinforcement Corrosion - Its Impact on Features of Steel PSC Strand

2020 ◽  
Vol 868 ◽  
pp. 57-64
Author(s):  
Vítězslav Vacek ◽  
Jiří Kolisko ◽  
Petr Pokorný ◽  
Michaela Kostelecká
Keyword(s):  
Maraging Steel ◽  
Prestressed Concrete ◽  
Mechanical Characteristics ◽  
Concrete Structures ◽  
Steel Reinforcement ◽  
Reinforcement Corrosion ◽  
Anticorrosion Protection ◽  
Long Time ◽  
Prestressed Reinforcement ◽  
Prestressed Structures

Steel reinforcement made of refined maraging steel in the form of wires and strands has been for a long time used commonly for reinforcement of prestressed concrete structures. Defects on some of them and unfortunately even accidents of some cases of bridge objects, mainly recently published by media, related to corrosion of prestressed reinforcement awoke interest of both professional and wide non-professional public related to its durability. This issue also opens up a question of durability and liability of prestressed structures. In majority of existing prestressed structures the anticorrosion protection of reinforcement was traditionally secured mainly by alkalinity of the environment, i.e. concreting and/or grouting of prestressed elements in ducts. The abstract presents information related mainly to mechanical characteristics of corrosion-affected prestressed elements.

Prestressing Steel Ropes - Corrosion Impact on its Properties

2020 ◽  
Vol 309 ◽  
pp. 272-280
Author(s):  
Jiří Kolísko ◽  
Vítězslav Vacek ◽  
Petr Pokorný ◽  
Michaela Kostelecká
Keyword(s):  
Maraging Steel ◽  
Prestressed Concrete ◽  
Mechanical Characteristics ◽  
Concrete Structures ◽  
Steel Reinforcement ◽  
Prestressing Steel ◽  
Anticorrosion Protection ◽  
Long Time ◽  
Prestressed Reinforcement ◽  
Prestressed Structures

Steel reinforcement made of refined maraging steel in the form of wires and tendons has been for a long time used commonly for reinforcement of prestressed concrete structures. Defects on some of them and unfortunately even accidents of some cases of bridge objects, mainly recently published by media, related to corrosion of prestressed reinforcement awoke interest of both professional and wide non-professional public related to its durability. This issue also opens up a question of durability and liability of prestressed structures. In majority of existing prestressed structures the anticorrosion protection of reinforcement was traditionally secured mainly by alkalinity of the environment, i.e. concreting and/or grouting of prestressed elements in ducts. The abstract presents information related mainly to mechanical characteristics of corrosion-affected prestressed elements.

Numerical Modeling of Time-Dependent Deformations of Concrete at 3D Analysis of Structures

2020 ◽  
Author(s):  
◽  
Ante Džolan
Keyword(s):  
Reinforced Concrete ◽  
Prestressed Concrete ◽  
Concrete Structures ◽  
Real Life ◽  
Nonlinear Behavior ◽  
3D Analysis ◽  
Actual Behavior ◽  
Realistic Simulation ◽  
Highly Nonlinear ◽  
Prestressed Structures

Concrete is a material with highly nonlinear behavior. In parallel, there are numerous secondary effects in concrete, such as aging, shrinkage, and creep, which further complicate the realistic simulation of reinforced concrete and prestressed concrete structures. In modern times, due to bolder construction, increasing spans and high rising construction, the need for realistic simulation of the behavior of concrete structures under conditions of various types of loads is becoming more pronounced. On the other hand, models with a small number of real-life parameters that can describe the actual behavior of concrete as accurately as possible are necessary. One such model, the previously developed model Precon 3D, which is based on a small number of parameters and can very well describe the behavior of concrete, reinforced concrete and prestressed structures for short-term static loads was taken as the basis for this work. Through this work, the numerical model Precon 3D has been upgraded with a model for following the behavior of concrete during time, i.e. the model has been upgraded with a model of creep and shrinkage of concrete, which is necessary for following the behavior of prestressed structures. The developed software has been tested against several experimental examples from the literature, with a very good match between numerical and experimental results.

DEVELOPMENT OF EMBEDDED MINI-SENSOR FOR DIAGNOSIS OF CORROSION OF STEEL REINFORCEMENT IN CONCRETE NONDESTRUCTIVELY

2016 ◽  
Vol 3 (2) ◽  
Author(s):  
Mohamed A. Ismail ◽  
Han-Seung Lee ◽  
Mohd Warid Hussin
Keyword(s):  
Reinforced Concrete ◽  
Polarization Resistance ◽  
Concrete Structures ◽  
Steel Reinforcement ◽  
Reinforced Concrete Structures ◽  
Chloride Ingress ◽  
Reinforcement Corrosion ◽  
Maintenance And Rehabilitation ◽  
Corrosion Of Steel ◽  
Non Destructive

Corrosion of steel reinforcement embedded in concrete is one of the main causes of degradation of reinforced concrete structures. Degradation occurs in reinforced concrete structures from corrosion caused by the Chloride ingress into concrete. That degradation has a severe impact on the structure in terms of maintenance and rehabilitation costs. Therefore, early detection of reinforcement corrosion is important for efficient maintenance, repair and planning. Meanwhile, the evaluation of the corrosion of reinforcement by non-destructive measurements have been used a lot. In particular CM-II (corrosion meter) is used to measure the polarization resistance, but has some disadvantages. Embedded mini-sensor has been developed in order to overcome these disadvantages. In this study, measurement of corrosion by using the mini-sensor is compared with the measured results by CM-II to verify the validity of the newly developed mini senor. Results show that there are agreement in trends of the parameters measured and as such the developed mini sensor has a promising start to be used.

scholarly journals Prestressed concrete seismic design

1969 ◽  
Vol 2 (3) ◽  
pp. 251-266
Author(s):  
K. E. Williamson
Keyword(s):  
Reinforced Concrete ◽  
Seismic Design ◽  
Prestressed Concrete ◽  
Structural Engineering ◽  
Civil Engineering ◽  
Concrete Structures ◽  
Earthquake Resistance ◽  
Reinforced Concrete Structures ◽  
The University ◽  
Prestressed Structures

This paper is reproduced from the proceedings of a seminar on "Seismic Problems in Structural Engineering" arranged by the Departments of Civil Engineering and Extension Studies of the University of Canterbury, and held in Christchurch from May 13 
to 16, 1968. Another paper from that seminar, also published 
in this issue of the Bulletin, discusses requirements for ductility in reinforced concrete structures. The present 
paper makes a comparison of prestressed concrete with reinforced concrete, and discusses the factors to be considered 
in the design of prestressed structures for earthquake resistance.

Long-Term Mechanical Properties of Fiber Reinforced Polymer Bars Exposed to Alkali Environment: Experimental Investigation

2016 ◽  
Vol 722 ◽  
pp. 27-32
Author(s):  
František Girgle ◽  
Lenka Bodnárová ◽  
Anna Matusikova ◽  
Vojtěch Kostiha ◽  
Jan Prokeš ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Concrete Structures ◽  
Steel Reinforcement ◽  
Advanced Composite Materials ◽  
Long Time ◽  
Frp Reinforcement ◽  
High Alkali ◽  
The Impact ◽  
Whole Life Cycle

This paper deals with actual issues concerning the design and the utilization of modern composite reinforcement (FRP) in concrete structures. These advanced composite materials are, especially if the whole life cycle of the structure is considered, gradually becoming a convenient alternative to ordinary steel reinforcement. The structure reinforced with FRP reinforcement (as well as the structure reinforced with steel reinforcement) has to be designed with regard to sufficient endurance, serviceability and durability. The long-term material properties of FRP reinforcement embedded in concrete, which are influenced by temperature, load magnitude and ambient environment, must be considered during design of the structure. A high alkali environment of concrete with pH higher than 12.0 acts mainly on glass fibres which degrade and their mechanical properties are reduced consequently. The used matrix creates a barrier which insulates the bearing fibres against alkali ions attack. The main objective of the paper is therefore to describe behaviour of composite as a whole. The experimental approach and results which were reached during the tests are also presented. An effort was to specify the impact of alkali environment on the long-time properties of developed reinforcement which could be used in durable concrete structures.

scholarly journals Propuesta de un nuevo indicador para definir la ductilidad aplicada a la corrosión del acero de refuerzo en estructuras de hormigón = Proposal of a new indicator to define ductility applied to corroded steel reinforcement on concrete structures

2015 ◽  
Vol 1 (2) ◽  
pp. 42
Author(s):  
E. Moreno ◽  
M. I. Prieto ◽  
M. N. González ◽  
N. Llauradó
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structures ◽  
Steel Corrosion ◽  
Steel Reinforcement ◽  
Single Parameter ◽  
Reinforced Concrete Structures ◽  
Reinforcement Corrosion ◽  
Accelerated Corrosion ◽  
Steel Bars ◽  
Reinforcing Steel Corrosion

ResumenLa carbonatación del hormigón o la intrusión de cloruros en suficiente cantidad para alcanzar el nivel de las barras, es desencadenante de la corrosión de la armadura. Uno de los efectos más significativos de la corrosión del acero de refuerzo en estructuras de hormigón armado es la disminución de las propiedades relacionadas con la ductilidad del acero. El reforzamiento tiene un efecto decisivo en la ductilidad global de las estructuras de hormigón armado. Se utilizan diferentes códigos para clasificar el tipo de acero en función de su ductilidad usando los valores mínimos de varios parámetros. El uso de indicadores de ductilidad asociados a diferentes propiedades puede ser ventajoso en muchas ocasiones. Se considera necesario para definir la ductilidad por medio de un solo parámetro que tiene en cuenta los valores de resistencia y deformación simultáneamente. Hay una serie de criterios para definir la ductilidad del acero mediante un único parámetro. El presente estudio experimental se ocupa de la variación en la ductilidad de las barras de acero embebido en hormigón cuando se expone a la corrosión acelerada. Este trabajo analiza la idoneidad de un nuevo indicador de la ductilidad utilizado en barras corroídas. AbstractThe carbonation of concrete or the chlorides ingress in such quantity to reach the level of bars is triggers of reinforcement corrosion. One of the most significant effects of reinforcing steel corrosion on reinforced concrete structures is the decline in the ductility-related properties of the steel. Reinforcement ductility has a decisive effect on the overall ductility of reinforced concrete structures. Different Codes classify the type of steel depending on their ductility defined by the minimum values of several parameters. Using indicators of ductility associating different properties can be advantageous on many occasions. It is considered necessary to define the ductility by means of a single parameter that considers strength values and deformation simultaneously. There are a number of criteria for defining steel ductility by a single parameter. The present experimental study addresses the variation in the ductility of concrete-embedded steel bars when exposed to accelerated corrosion. This paper analyzes the suitability of a new indicator of ductility used in corroded bars.

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