The growing population and increasing demand for surface transportation have highlighted the importance of maintaining safe and reliable civil infrastructures for daily use. Among all civil infrastructures, bridges are one of the most important elements in the transportation system. As such, to prevent any failures caused by aging and environmental impacts, bridges require periodic inspections. This becomes even more critical due to climate change and its effect on bridges, especially in the coastal regions. Most of the inspections conducted incorporate the visual type of evaluation due to its simplicity. However, with the current developments in new technologies, there is a need for more advanced techniques of structural health monitoring (SHM) methods to be incorporated in the maintenance programs for more accurate and efficient surveys. In this paper, non-destructive testing (NDT) methods applicable to steel bridges are reviewed, with a focus on methods applicable to local damage detection. Moreover, the methodology, advantages and disadvantages, and up-to-date research on NDT methods are presented. Furthermore, the application of novel NDT techniques using innovative sensors, drones, and robots for the rapid and efficient assessment of damages on small and large scales is emphasized. This study is deemed necessary as it compiles in one place the available information regarding NDT methods for in-service steel bridges. Access to such information is critical for researchers who intend to work on new or improved NDT techniques.

Ultra-high performance concrete (UHPC) is a durable material that allows the construction of innovative structural elements and conforms with accelerated bridge construction (ABC) goals. The main idea of this research is to utilize UHPC to prefabricate a shell that acts as a stay-in-place form for bridge columns. The prefabricated shell eliminates the conventional formwork while reducing the on-site construction time and acting as a durable protective layer for the normal concrete inside the shell against environmental attacks. In addition, the UHPC shell provides additional confinement to the column concrete, which improves the column’s structural performance. During construction and after completing the column reinforcement work onsite, based on the conventional construction methods, the prefabricated UHPC shell is placed around the column reinforcement, followed by casting a portion of UHPC for a column-to-footing connection, which improves the capacity of the connection and shifts the plastic hinge zone above the connection. Once the UHPC portion hardens, normal concrete is placed inside the shell, forming a permanent concrete-filled UHPC shell. The construction process is finalized by placing and connecting a prefabricated cap beam to the column through the same developed connection as that in this research. This technical note presents the development of two test specimens using an UHPC shell in lieu of a conventional formwork with the advantage of improving the column performance and durability.

Humankind has not set foot on the Moon in more than half a century. Since then, our best chance to get back to the Moon and stay, is now, with the Artemis program, led by National Aeronautics and Space Administration (NASA). To achieve a lunar presence for longer than 3 days, the astronauts will need a safe lunar habitat that will protect them from the harsh environment on the lunar surface. When designing for a structure that is quite literally out of this world, there are many different factors to be considered, which are not present on Earth. Humanity went through thousands of years of construction to develop their understanding of structural shape effectiveness, construction material, understanding of the stresses and forces that are present in the Earth environment, and summarized them into various building codes. However, most of that knowledge is not applicable for the lunar environment due to different factors and lack of atmosphere. Various conceptual designs were presented and published around the world, but a more comprehensive study needs to be conducted to account for all the technical requirements and extreme factors affecting the decision of the lunar habitat. This paper briefly summarizes the most important data on the technical requirements and environmental factors to be considered for a successful design and continues with development of a preliminary in-depth and systematic framework, through the Pugh Matrix, to determine an optimal design for a lunar structure. 23 different evaluation criteria were used. Even though numerous different lunar habitat concepts were published throughout last 50 years, they were summarized in eight different concepts. The full decision matrix is presented, with the 3D printed structures as baseline concepts, and Modular Block Structures as the most viable option.