Seasonal Variation and Age-related Changes in the Relative Permittivity of Concrete Bridge Decks on Korea Expressways
نویسندگان
چکیده
The purposes of this study were to investigate the seasonal variations in the relative permittivity of actual concrete bridge decks of various ages on Korea expressways, and to propose a practical way to calibrate two critical effects, to assess the condition of the concrete bridge decks with better accuracy. For these purposes, fifty-three actual concrete bridge decks on Korea expressways were scanned using an air-coupled ground penetrating radar (GPR) system, and the relative permittivity of the concrete was evaluated from the GPR data in the field. A statistical analysis showed that the relative permittivity of the concrete bridge decks in Korea are closely correlated with seasonal changes and concrete ages. For concrete bridge decks aged 10 years or older, the effect of concrete age was not as significant as that of relative humidity of the air on relative permittivity of concrete. Based on the results, a simple calibration process was proposed to suppress the effects of seasonal variation and age of concrete on the measured relative permittivity of the concrete decks on actual bridges. As will be discussed, the resulting relative permittivity method produced better agreement with the current condition of the concrete bridge decks as determined by visual inspection and other complementary methods (energy attenuation of GPR signals and corrosion potential measurements) than without the calibration process.
منابع مشابه
Assessing the Performance of Corroding RC Bridge Decks: A Critical Review of Corrosion Propagation Models
Corrosion of steel reinforcement is one of the most prevalent causes of reinforced concrete (RC) structures deterioration in chloride-contaminated environments. As a result, evaluating the impact of any possible corrosion-induced damages to reinforced concrete bridges strongly affects management decisions: such as inspection, maintenance and repair actions. The corrosion propagation phase is a ...
متن کاملTransmission and Reflection Characteristics of a Concrete Block Wall Illuminated by a TM-polarized Obliquely incident wave
Typically, many of the modern buildings have concrete walls constructed from cinder block walls, that have periodic nature in their relative dielectric constant. This periodic nature excites higher-order Floquet harmonic modes at microwave frequencies, which leads to the propagation of scattered waves along with non-specular directions. Periodic structures exhibit different behaviors when illum...
متن کاملControl of Cracking in Bridge Decks: Observations from the Field
Crack surveys of bridge decks, performed over a 10-year period in northeast Kansas as part of three studies, provide strong guidance in identifying the parameters that control cracking in these structures. The surveys involve steel girder bridges—bridges that are generally agreed to exhibit the greatest amount of cracking in the concrete decks. The surveys include monolithic decks and decks wit...
متن کاملPrecast, Pretensioned, Post-Tensioned Concrete for Bridge Decks
The problem of concrete bridge deck deterioration on many of our newer as well as older bridges is severe, somewhat perplexing as to cause, and difficult to solve. Furthermore, the cost to highway agencies for their repair, and the cost of delay to the highway user, can be extremely large. The use of precast, prestressed concrete for bridge decks is a con cept of construction or reconstruction...
متن کاملImproved GPR-based Condition Assessment of Reinforced Concrete Bridge Decks Using Artificial Neural Network
Accounting for the effect of rebar depth variation is one of the most important and challenging tasks to accurately assess the condition of reinforced concrete elements using ground penetrating radar (GPR) technique. In current practices, this task is performed on the individual basis, as for each bridge deck a unique depth correction model is derived from the GPR data collected on it. It is fo...
متن کامل