Corrosion of reinforcing and prestressing steel due to chloride contamination is one of the primary causes of deterioration of concrete structures. A review of published literatures shows that the research on the deterioration of mechanical properties of reinforcing steel is more than that on prestressing strands, even though the corrosion of prestressing strands may trigger structural collapse...

Prestressed concrete bridges currently account for 45% of bridges built in the last 5 years in the United States. This has resulted in an increase in the number of deficient bridges composed of prestressed concrete, which requires a better understanding of the on-site performance of this building material. The use of new materials, such as high-performance concrete, in conjunction with prestres...

This paper presents a proposal of a test setup and methodology for testing the transfer length evolution through time of prestressing reinforcement in pretensioned prestressed concrete members, aimed at providing a basis for standardization. The proposed test method is based on the instantaneous and time-related analysis of the prestressing reinforcement force profile at only one end of a prete...

This paper presents the results of the tests and analysis on the coefficient of thermal expansion for the steel strand under combined low temperatures and prestressing forces. A test program was firstly carried out to study the thermal expansion behaviour of the seven-wire strand under combined different low temperatures ranging from 20 to 165 C and different prestressing levels ranging from 0 ...

Corrosion of reinforcing and prestressing steel due to chloride attack is one of the major causes of deterioration of concrete structures. This is of most concern because of the associated reduction in steel cross-sectional area, spalling and loss of bond. In the case of prestressed concrete structures, the corrosion of prestressing strands can lead to a sudden failure due to higher stress leve...

External prestressing has become a primary method for strengthening existing concrete beam and has been increasingly used in the construction of newly erected ones, particularly railroad bridges in recent years. In order to evaluate the effect of this method, the static and dynamic behavior of a T-frame beam reinforced by external prestressed strengthened concrete beam was analyzed by 3D finite...

This paper investigated experimentally the feasibility of the method to estimate the stress in the prestressing tendons of prestressed concrete bridges using the magnetic field induced by a moving electromagnet. This method is based on the Villari effect in which the magnetic permeability of prestressing tendons changes when subjected to a mechanical stress. The test results show high linearity...

Failures of road embankments on discontinuous permafrost commonly occur during thawing of the foundation soil. As an approximation, weak zones created by thawing of discontinuous permafrost can be considered as ‘voids’ within the foundation. Geosynthetic reinforcements have been used to bridge these ‘voids’ and provide support to the embankment fill. This paper presents results of a numerical i...

There are more than 130,000 prestressed concrete bridges in the United States with about 37,000 bridges being more than 30 years old. Prestressing steel strands are an important construction element used in these bridges and are critical to their performance. Presently there is no effective Nondestructive Evaluation (NDE) technology for condition assessment of these prestressing strands once th...

Prestressing steel wires are commonly used as reinforcement elements in structures bearing fatigue loads. These wires are obtained by a conforming process called cold drawing, where a progressive reduction of the wire diameter is produced, causing residual stress in the commercial wire. The aim of this paper is to analyze the effect of diverse in-service cyclic loading conditions (cyclic loadin...