광케이블은 유리를 가는 실처럼 만든 광섬유에 빛을 통하여 신호를 보내어 정보를 보내는 원리로써, 송신측에서 반도체 레이저에 의하여 정보를 빛으로 변환한 후 전송하면 수신측에서 전기 신호로 변환하여 정보를 수신하는 체계이며, 주요 성분은 PE등의 플라스틱 수지와 철, 알루미늄, 광섬유(SiO2 또는 GeO2)등으로 구성되어 있다. 현재 광케이블의 수요가 급증함과 동시에 폐광케이블 발생량 또한 급속도로 증가되고 있으며, 연간 약 3만톤 가량이 발생되나 재활용업체에서는 소형규모의 단순탈피장치로 외피인 HDPE(합성고밀도폴리에틸렌)만을 회수하고 다량의 플라스틱 수지와 알루미늄, 광섬유에 포함되어있는 광물자원(Ge 150만원/kg) 등은 단순 적재해 놓거나 매립, 소각하는 등 관련 재활용 기술이 매우 낮은 실정이다. 따라서 본 연구는 폐광케이블 재활용을 위하여 자동화 공급 기술, 선택적 국부가열, 절개 및 선별등의 기술을 통하여 각각의 유용자원을 분리/회수할 수 있는 1Ton/day 이상의 폐광케이블 자원회수장치를 연구하였다.

To examine the practical potentials of V-ties to provide a confinement to a strengthening jacket section of existing reinforced concrete members, direct bond tests were conducted under a parameter of the V-tie details. Test results showed that V-ties with headed-end had a higher bond strength than those with the other details.

게르마늄은 주로 광섬유, 반도체 등에 사용되고 있으며, 고가의 희소금속이므로 게르마늄에 대한 회수 및 재활용 기술 개발은 각국에서 경쟁적으로 진행되고 있다. 하지만 국내에서는 게르마늄에 대한 재활용 실적이 전무하며, 전량을 수입해서 사용하는 희소금속이므로 게르마늄에 대한 재활용 기술 개발이 필수적이다. 특히, 광케이블에 사용되는 광섬유에는 1km당 약 0.54g의 게르마늄을 함유하고 있으므로, 본 연구에서는 광섬유를 게르마늄 추출 대상으로 선정하였다. 또한, 게르마늄은 1kg당 150만원의 고가 희소 금속이므로 관련 기술 개발시 파급효과가 클 것으로 판단하였다. 본 개발 기술은 광섬유에서 실리카(Si)와 합금형태로 존재하는 게르마늄을 추출하기 위하여 Na 화합물과 염산을 이용한 선택적 추출을 적용하였으며, 게르마늄의 추출 효율을 알아보기 위하여 추출액에 대한 ICP 분석을 실시하였다. 본 연구에서 사용한 Na 화합물은 광섬유의 주성분인 실리카 성분을 석출시켜 제거하는 역할을 하며, 추출 용매인 염산은 질산, 황산과의 추출 효율을 비교하여 최종 추출 용매로 선정하여 실험을 진행하였다.

The purpose of this study was to evaluate the sulfate attack of ternary blended concrete based on low-heat cement for reducing the heat of hydration. The main parameters were water-to-binder ratio and curing temperature on the matching mixtures. Test results revealed that compressive strength ratio at each age was superior to the developed mixtures than control mixtures. Whereas, the mass change ratio was superior to the control mixture at all ages.

The purpose of this study was to evaluate the shrinkage of ternary blended concrete based on low-heat cement for reducing the heat of hydration. The main parameters were water-to-binder ratio and curing temperature(5, 20, 40℃). Test results showed that the shrinkage significantly was influenced by water-to-binder ratio than binder type. The shrinkage strain of all of the mixtures was increased with increasing the curing temperature.

To examine the in-place strength development of concrete of nuclear containment structures with the wall thickness of 1200 mm, mock-up wall specimens were prepared. For maturity evaluation, the temperature rise in the wall specimens owing to hydration heat of cementitious materials was also measured. The in-place strength of concrete was measured using core specimens collected at different locations of mock-up walls. Test results showed that in-place compressive strength development was 1.5 times higher than the strength measured from the standard cylinders. This indicates the maturity effect is needed to be considered in predicting the compressive strength development of concrete in mass structures.

Many accidents by side-wind have been reported worldwide when vehicle passes through the bridges. In order to solve this problem, it needs to investigate the accident cases and to classify the accident types. Therefore, it can lead to adequate plans for prevention.

The objective of this study is to investigate the safety of the slab type precast module. To achieve this, the designed slab type precast module was made using the manufacturing facility for the precast modular superstructure and the flexural performance test was conducted.

The modular road system was proposed to achieve the fast construction and the closed-loop chain of the resources in the field of road construction. In this study, the concept of the joint system that complies with the goal of the development of modular road system was proposed.

In this study, the mock-up test of a girder-type precast module was conducted for evaluated construction applicability. Results of mock-up test, girder type precast module`s process of manufacturing and transport, fabrication, installation was satisfied the construction application.

This study was intended to estimate the axial deformation of joint between pavement modules in the rapid-constructible modular pavement system, and to investigate the applicability of two-phase composites for a joint material, which was composed of cement paste, epoxy, or polyurethane as a matrix and sand as particles.

In this study, the measurement items for establishing the structural health monitoring for super tall buildings were proposed. The items were classified in level of structure, as a structure level and a member level. The external forces and internal responses are measured at each level to monitor the behavior of structure in real time.

In this study, the methods of structural analysis modeling for establish the structural health monitoring system of super tall buildings was proposed. The analysis was conducted through the stages of construction and the results was reflected to the final analysis model.

The current road length in Korea is 106,000km, and the demand for new road construction is nearly reaching its limits. Even the policy of the road is on the turning point of new construction to maintenance and management. The need of effective maintenance for existing road infra is increasing, and as for new road, the paradigm is changing to characterized road construction. The development of technology for customized road system through modularization is actively tried out to satisfy the needs of multi-functional roads. In this study, the required performance about joint of modular road system was researched

In USA and Europe, a study for precast modular road system has been performed over the last 20 years to construct the road rapidly and to reduce traffic congestion during repair and rehabilitation of deteriorated concrete pavements. This precast modular road system could be applied to exclusive bus lanes and roads in industrial area.

To design the program that can effectively support the port facilities management system for to reduce maintenance costs, to ensure the safety and to extend the age of the facilities(docking facilities, counter facilities, pavement etc.) by effective repair at the optimum time is the purpose of this study. The program was designed by considering the business processes of the system. The program was divided into the database and the operating programs, and composed of a total of five modules.

Domestic port facilities has increased rapidly since the late 1980s. Therefore, future maintenance demand will increase significantly. However, because of the limited budget, the maintenance budget will not increase significantly. In this study, maintenance prioritization method was proposed by Delphi study for the efficient use of the maintenance budget.

The purpose of this study is to collect and analyze the condition and history data of the port facility for the systematic management. To this end, the preliminary and background data were collected through each related organization. The present state data of the port facility were established by the analysis of collected data. Based on the result of this study, the systematic data were constructed for the port facility's systematic management

This paper presents the results of researches to developing the precast modular bridges. Procedures to decide types of bridges, results of the optimizations to minimize the cross sectional areas, concepts of joints between modules, and the results of the experimental tests to evaluate the performance of joints are presented in this paper. It is expected that the precast modular bridges may be the effective alternatives to rapidly replace deteriorated bridges and damaged bridges by disasters.

To evaluate the seismic performance of CFFT pier reinforced by FRP, quasi-static loading tests have been conducted using the real-scaled specimens in this study. The cast in placed CFFT specimen and the precast CFFT specimens were used in these tests. From the results of the tests, it is observed that the ultimate deformation and the ductility can be improved by FRP reinforcement though the hoop reinforcement is minimized.