The present study reviews bridge inspection practices and bridge management programs in China, Japan, Korea, and U.S. Bridges play an essential role in transportation systems and in the economic production process. Transportation agencies should maintain bridges in acceptable conditions to provide a desirable level of service to the public within limited budgets. In addition, a number of bridges are aging rapidly in these four countries. Fortunately, since several countries have experienced deteriorated bridges due to aging, the countries considered in this study have already developed comprehensive bridge management system (BMS) and bridge inspection practices. Therefore, the goal of this paper is to search for and synthesize useful knowledge on BMSs and bridge inspection practices of the four countries. Finally, recommendations that will serve as guidance to transportation agencies for potential enhancements to BMS and bridge inspections are presented.

Integral abutment bridges (IABs) are now a routine construction and design of choice for many DOTs as bridges are replaced or for new roadways. However, current design and analysis methodologies have not matured substantially because of a lack of available long-term field data. Often current analysis methods predict bridge behavior that is much different from observed. Because of thermal loading, time-dependent effects, and soil-structure interaction, significant irreversible abutment displacements and rotations occur. The primary objective of this paper is to report the actual in situ measurements obtained at four short to medium-long IABs and one weather station, all located in central Pennsylvania. A total of 240 instruments was installed on four IABs during bridge construction and monitored continuously. Monitoring duration at each bridge ranges from 2.5 years to nearly 7 years, having initiated the program in 2002 and continuing to the present. Because of a unique environmental issue, the bridges wer...

With the recent development of 3D printing technology, concrete materials are sometimes used in 3D printing. Concrete structures based on 3D printing have been characterized to have the form of multiple layer build-up. Unlike general concrete structures, therefore, the 3D-printed concrete can be regarded as an orthotropic material. The material property of the 3D-printed concrete’s interface between layers is expected to be far different from that of general concrete bodies since there are no aggregate interlocks and weak chemical bonding. Such a difference finally affects the structural performance of concrete structures even though the interfaces are formed before initial setting of the concrete. The current study mainly reviewed the changes in fracture energy (toughness) with respect to various environmental conditions of such interface. Changes in fracture energies of interfaces between concrete layers were measured using low-speed Crack Mouth Opening Displacement (CMOD) closed loop concrete fracture test. The experimental results indicated reduction in fracture energy as well as tensile strengths. To improve the tensile strength of interfaces, the use of bridging materials is suggested. Since it was assumed that reduction in fracture energy could be a cause of shear strength, to evaluate the reduced structural performance of concrete structure constructed with multiple interfaces by 3D printing technology, the shear strength of RC beam by 3D printing technology was predicted and compared with that of plain RC beam. Based on the fracture energy measured in this study, Modified Compression Field Theory (MCFT) theory-applied Vector 2 program was employed to predict the degree of reduction in shear strength without considering stirrups. Reduction factors were presented based on the obtained results to predict the reduction in shear strength due to interfaces before initial setting of the concrete.

The present study is designed to determine the effect of major parameters on maximum total bending moments of curved girders, establish the relationship between key parameters and girder distribution factors (GDFs), and develop new approximate distribution factor equations. A level of analysis study using three numerical models was performed to establish an appropriate numerical modeling method on the basis of field test results. A total of 81 two-traffic lane curved bridges were analyzed under HL-93 loading. Two approximate GDF equations were developed based on the data obtained in this study: (1) a single GDF based on total girder normal stress; and (2) a combined GDF treating bending and warping normal stress separately. The two equations were developed based on both an averaged coefficient method and regression analysis. A goodness-of-fit test revealed that the combined GDF model developed by regression analysis best predicted GDFs. The present study demonstrated that radius, span length, cross frame ...