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.

최근 국내에서 토목 및 건축구조물의 노후화 및 성능저하에 따른 사회적인 우려가 발생하고 있다. 일반적으로 노후 구조물의 보수보강 방법으로는 외부 부착공법이 가장 많이 사용되고 있으며 시공 용이성을 위하여 GFRP나 CFRP Sheet나 Plate를 활용한 부착 보강방법이 활발히 적용되고 있다. 그러나 이들 방법은 온도에 취약하며 탄소섬유의 경우 경제성이 낮다는 우려가 발생한다. 본 연구에서는 친환경적이고 내열성이 상대적으로 우수한 현무암 섬유(BFRP)를 활용하여 온도변화 및 콘크리트 표면 내 균열발생에 따른 BFRP-콘크리트의 인장 부착성능 및 파괴 패턴을 실험적으로 평가하였다. 그 결과 구조물의 온도가 상승함에 따라 BFRP-콘크리트 계면의 부착성능은 약 30%정도 감소하는 것으로 나타났으며 내열성 수지를 사용한 보강재의 경우 일반 함침용 에폭시 수지보다 부착성능이 다소 우수한 것으로 평가되었다. 콘크리트 표면 내 균열 발생된 경우 균열의 폭이 증가함에 따라 부착 성능은 약 20%씩 감소하는 것으로 나타났다. 하지만 균열보수제로 보강 후 계면에서의 부착성능의 경우, 보강 전 대비 약 30% 정도의 개선효과를 나타내었다.

본 연구에서는 보수 모르타르와 직접 혼합 가능한 결정성장형 자기치유 고상캡슐을 제조하였으며, 자기치유 고상캡슐이 혼합된 보수 모르타르의 품질 및 균열 치유 성능 특성을 평가하였다. 자기치유 고상캡슐을 혼합한 보수 모르타르의 테이블 플로우 및 공기량 평가 결과 혼합율에 관계없이 테이블 플로우 및 공기량은 큰 영향이 없는 것으로 나타났다. 압축강도는 캡슐 혼합율이 증가할수록 강도가 감소하는 경향이 나타났다. 정수위 투수시험에 따른 균열 치유 특성 평가 결과 초기 투수량이 감소하는 결과가 나타났으며, 시간 경과에 따라 반응 생성물 발생하여 균열이 치유되는 것을 확인 할 수 있었다.

In this study, an experimental evaluation was made on the change of the pull - out performance of BFRP concrete interface after repairing cracks on the lower surface of reinforced concrete by using basalt fiber which is environment friendly and heat - resistant compared to glass fiber. The test standard was ASTM D7522 / D7522M, and the influence factor was considered as the crack thickness. Test results showed that the fracture pattern was the same regardless of the crack thickness and the bond stress was measured similarly.

In this research, the application of repair methods of water leakage cracks using self-healing technologies for subway tunnels is presented. In order to apply crack self-healing water stop agents and quick setting agents in subway tunnels, laboratory and field tests were performed based on various previous researches. Especially, this study focused on development of crack repair materials and their new repair methods. Therefore, various repair materials were examined for new repair materials with self-healing capability applied to crack sealing method and to patching repair method. The results show that the proposed water leak repair methods using water stop agent, quick setting agent and patching materials using self-healing ingredient were effective under the subway tunnel conditions. It is preferable in water leak repair to add self-healing components to sealers and water stop agents.

This study is subway tunnel field application about repair materials with crack self-healing capability. It was found that it showed good durability compared to the existing repair materials through lab test. Utilization of these mortars may have high potential for a new repair material.

In this study, the behavior of the existing tunnel was measured by automation system to analyze the characteristics of lining longitudinal cracks. The characteristic of the infusion material which it is applicable to crack repairing was considered by grasping the overall behavior including the temperature and the crack width change, and etc., From this, the reasonable repair period for the complement efficiency enhancement was trying to be determined.

Structure analysis and field instrumentation were carried out to understand the cause of crack taken place on a cover plate of a lower flange in plate-girder bridge. A cause of the crack turn out to be fatigue stress so that the bridge is in need of repair and reinforcement such as surface grinding, rewelding after gouging and reinforcement for a part of welding on a cover plate.

Restraint to drying shrinkage is the most common cause of concrete cracking. In many applications, drying shrinkage cracks are inevitable. In this paper, the surface cracks of soil concrete caused by drying shrinkage were considered to become an one of concrete textures. So, laboratory shrinkage tests were conducted and the results were applied to the field applications. The study results were summarized as follows; First, the use of vinyl sheets and concrete polymers helped to control the concrete cracking. Second, crack propagation usually started at the interfaces of soil concrete slabs and the cracks grew to the inner slabs. Third, surface cracks of soil concrete slabs could be an one of good concrete textures.

본 논문은 터널 콘크리트 구조물의 보수를 위한 무기계 균열주입기술의 표준화에 관한 연구이다. 본 연구를 위하여 균열보수공사가 필요한 터널 라이닝 및 박스 구조물을 선정하여, 균열폭에 따른 주입량, 주입시간 및 주입압력, 주입압력과 주입시간, 구조물 규모에 따른 주입량, 구조물별 균열 위치에 따른 주입량, 균열폭 및 구조물 두께와 주입시간의 관계에 관하여, 현장 조사와 시험평가를 수행하여 구조물의 종류 및 균열의 크기에 따른 균열보수재의 주입압력, 주입량 및 주입시간 등을 명확히 파악하였다.