In the contemporary era, 3D printing technology has become widely utilized across diverse fields, including biomedicine, industrial design, manufacturing, food processing, aerospace, and construction engineering. The inherent advantages of automation, precision, and speed associated with 3D printing have progressively led to its incorporation into road engineering. Asphalt, a temperature-responsive material that softens at high temperatures and solidifies as it cools, presents distinctive challenges and opportunities in this context. For the effective implementation of 3D printing technology in road engineering, 3D printed asphalt (3DPA) must exhibit favorable performance and printability. This requires attributes such as good fluidity, extrudability, and buildability. Furthermore, materials utilizing 3DPA for crack repair should possess high viscosity, elasticity, toughness, superior high-temperature stability, and resistance to low-temperature cracking. These characteristics ultimately contribute to enhancing pavement longevity and ensuring worker safety.

In this study, as the proportion of aged pipelines increases rapidly, in the event of an accident caused by corrosion and structural deterioration of metal pipes, appropriate overlay welding is applied in the field to partially repair it. The size of the base steel plate and the selection of a stable welding method were evaluated, and possible problems caused by the overlay welding were identified, and improvement measures were proposed. For the test, a new steel pipe coated with epoxy lining on the inner surface and polyethylene on the outer surface was subjected to a tensile test by processing the repaired specimen through overlay welding with a steel plate after artificial cracking, and structural safety was evaluated after repair. Furthermore, the influences of the size of the throat and the size of the steel plate were analyzed. As a result of the tensile test by dividing the repaired steel plate overlay into a constraint and non-constraint conditions, the tensile load was concentrated in the welded part and damage occurred in the welded part. It was found that the maximum load leading to breakage increases as the size of the welding throat increases. In addition, it was found that the resistance to load increased slightly as the size of the overlaid steel plate increased, but the effect was not significant, confirming the need for repair in consideration of the site conditions. As a result of evaluating the damage to the coating material on the back side of the welding, it was confirmed that the coating material on the opposite side of the welding burned black(epoxy) or was greatly deformed by heat(polyethylene). Therefore, it is necessary to secure structural stability through repainting, etc. in order to prevent damage to the coating material on the opposite side during overlay welding.

군사용으로 먼저 개발되어 온 드론은 요소기술의 급격한 발전을 통해 민간 분야로 확대되면서 최근 다양한 산업분야에 활용되 고 있다. 이러한 시대적 흐름에 따라, 조선해양 산업계에서도 유지보수 및 점검용으로 드론의 활용이 유럽을 중심으로 본격화되고 있다. 이와 관련하여, 본 논문에서는 조선해양 분야에 적합한 드론의 기술개발을 위해 선박 및 해양플랜트의 유지보수 점검의 현상태를 진단함 으로써 드론 기술개발의 방향성을 제시한다. 즉, 조선해양용 드론이 이미 상용화 된 선진국의 기술력을 살펴보고, 조선해양 산업계에서 드론시대를 대비하여 해결해야 할 기술적 과제들을 소개한다. 또한, 이러한 드론의 시장성장 가능성을 전망함으로써 기술개발의 추진력 을 제공하고자 한다.

도로 포장 및 교면 포장의 노후화로 인해 이에 대한 보수는 지속적으로 이루어지고 있고 매년 증가하고 있다. 도로 및 교량의 유지보수는 교통량이 많은 낮 시간보다는 교통량이 상대적으로 적은 야간에 주로 수행되고, 교통량이 다시 많아지는 시간 이전에 신속히 마무리하고 교통개방을 해야 하기 때문에 노무자 의 인력관리 및 안전관리를 체계적으로 수행하기가 쉽지 않다. 본 연구는 주로 야간에 주어진 시간 내에 신속히 작업을 수행해야하는 유지보수공정에 대하여 노무자 의 업무 및 안전을 체계적으로 관리하기 위해 실시간 위치정보 시스템을 구축하고, 현장에 시범 적용하여 그 가능성을 살펴보았다. 유지보수 현장에 총 8개의 고정식 노드를 설치하고 작업자의 안전모에 이동식 노드를 설치하여 현장에서 노무자의 작업 패턴을 충분히 확인할 수 있었다. 그리고 시스템 상에서 현장을 1m 격자로 구분하고 위험지역을 시스템 상에서 부여하여 노무자가 위험지역을 진입할 경우 이를 실시간 으로 확인하고 위험여부를 통보 가능함을 확인하였다.

The electrophoretic deposition process of Ni nano-particles in organic suspension was employed for self-repairing of heat exchanger tubes. For this purpose, Ni nano-particles prepared by levitational gas condensation method were dispersed into the solution of ethanol with the addition of dispersant Hypermer KD2. For electrophoretic deposition of Ni nano-particles on the Ni alloy specimen, constant electric fields of 20 and 100 V were applied to the specimen in Ni-dispersed solution. It was found that as electrophoretic deposition proceeds, the size of the pit or crack remarkably decreased due to the agglomeration of Ni nano-particles at the pit or crack. This strongly suggests that the electrophoretic mobility of the charged particles is larger for the damaged part with a higher current value rather than outer surfaces with a lower current value.

In this study, chloride penetration in a repaired concrete using magnesium polymer ceramic (MPC) was assessed based on the NT BUILD 492. To investigate the effect of repaired material on chloride penetration, a cylinder OPC concrete specimen was fabricated and attached on the surface with MPC. Then, chloride penetration test was carried out on the combined concrete sample at a constant applied voltage (30 V) for 6 hours. It was found that most of chloride sources was passed though the interface between OPC and MPC, resulting in a loss of chloride in the material. Thus, it is needed to modify the conventional chloride penetration test for the repaired concrete specimen.

This report is contained to the repair guidelines of water-leakage crack and the standardization of performance evaluation testing method studied and reviewed to register to the domestic construction technique as the international standard, and to the introduction to the it’s research contents lasted three years between 2010 and 2013.

The goal of this study is to investigate an evaluated aerial work flatform for structure maintenance and repair. This study includes technical components and economic aspect. The investigation is extend and helpful to accomplish successful business according to foreign and domestic business.

This research is to understand the technology trends through the patent analysis of road pavement rehabilitation techniques. The target patents are open and registered from 1970's to 2010. It has been drawn the vulnerable technology part as a result of classifying and analyzing each patent by country, type of technology about the technology trends of rehabilitation techniques in the road fi