본 연구는 154℃로 2시간의 단기노화를 거친 혼합물로 제작한 공시체를 110℃에서 24, 48, 72, 96시간 동안 장기노화를 시켜 아스팔트 혼합물의 노화와 소성변형 저항성을 평가하였다. 혼합물의 노화 시간이 증가함에 따라 강성의 증가로 인한 소성변형 저항성이 증가할 것을 고려하여 변형강도를 이용해 단기노화와 장기노화를 거친 공시체에 대해 소성변형특성을 측정하였다. 또한 노화 시간의 증가에 따른 바인더의 노화 정도를 측정하기 위하여 GPC (Gel-permeation chromatograph) 분석을 통하여 대형분자비율(LMS(%))을 측정하였다. 노화 시간이 길어짐에 따라 LMS(%)가 증가하고 혼합물의 변형강도 값이 커지는 것을 확인하였다. 또한 상관성 분석으로부터 LMS(%)와 변형강도가 상관성이 높은 것으로 나타나 이를 통해 혼합물이 노화되면 소성변형 저항성이 증가됨을 확인하였다. 따라서 LMS(%)의 측정으로 아스팔트 혼합물의 바인더 추출 없이도 소성변형특성을 추정 가능함을 확인하였다.

The apartment structures built using tunnel form method in 1980's, are vulnerable to lateral loads since wall elements don't exist in longitudinal direction and especially they were not seismically designed. In this study, in order to evaluate the seismic performance of those apartment structures, nonlinear analysis was performed and static test was conducted using small scale partial specimen. Both shear and moment should be considered for the structure subject to lateral load. Most existing methods, however, consider only shear force in test specimen because it is difficult to realize the actual moment distribution of the practical structure, and furthermore axial force is often neglected. This study propose a testing method which can realize similar moment and axial force distribution of a specimen to that of the practical structure by controlling the lateral loading condition. Numerical analysis was performed using moment-curvature curve considering stiffness degrading parameter, ductility-based strength and energy dissipation. The result of this study shows that only 15~20% difference exist between analysis and test, which confirms that the performance of wall elements in a non-seismically designed wall type reinforced concrete apartment can be accurately evaluated.

The seismically design of building has objects to minimize in judge of people by preventing brittle fracture and to guarantee serviceability of building. But I come to the conclusion that the seismically design is not easy to use, even though we recently use it applyed with shear wall-type evaluation method, because we don't know how to estimate seismic performance of existing reinforced concrete wall-type apartment and evaluation method of wall-type apartment. so in this study, we conduct analysis program by using MIDAS-Gen & MIDAS-SDS, structure analysis program, after conducting a preliminary evaluation about research apartment by seismic performance evaluation method of existing safety & Technology corporation. In addition we show the problem when research apartment is applied with shear wall-type evaluation method that is estimate and grade of seismic performance level by capacity spectrum method.

Recently, earthquakes occur over 30 times a year in Korea. In addition, earthquakes originating from the neighborhood countries were sensed in Korea and caused serious human casualties and economic loss. In Japan, U.S.A., New Zealand and etc., forces seismic design of building structures to prevent seismic damage. In Korea, seismic design has been applied to building structures with a scale larger than defined in the building code since 1988. However, serious seismic damages are expected for wall-type apartment buildings, which were designed before 1988 without application of seismic design. Therefore, appropriate seismic retrofitting methods that are economical and easy to construct are required for such buildings. In this study, seismic retrofitting methods using steel plates or sections are developed for the wall-type apartment buildings. Proposed retrofitting methods improve lateral stiffness of the wall-slab system without excessive increment of loads on base structure. The effect of retrofitting using plates, T-sections and H-sections was examined experimentally for wall-slap system test models. In the experiment, the performance of the joint and slab of the test models was improved and the retrofitting effect was proved to be excellent.

Earthquake resistance design has been developed many countries like Japan, USA, Mexico, New Zealand etc., which countries have experienced many earthquakes. Nowadays, earthquake resistance design has come into worldwide use. In Korea, the seismic design regulations have been established since 1988 in order to minimize the economic losses. Recently performance based design method has been adopted as a new Earthquake resistance design method. These regulations, however, are targeted for newly constructed buildings, In Korea, there are no regulations for existing buildings that built before 1988. So, we need to prepare the regulations that evaluate the seismic performance, furthermore proper retrofitting design guideline needs to be proposed when remodeling old buildings. This study was performed that many existing apartments is being a Remodeling object when considering the present condition of existing apartment and the problerns of cost and environment in the future plan. When Remodeling construction is reviewed by former the Seismic Performance Evaluation Method, generating problems is evaluation by using Push-over. According to this, it provides the appropriate method of calculating the Seismic Performance Index.

Recent building structures are superior in its ability but they are light and flexible, and so have problems of habitability induced by building vibration. In general, the problem of vertical vibration is not considered in structural design. However, in terms of serviceability for inhabitants in buildings, the estimation of vertical vibration in design stage is important. Characteristics of vertical vibration is changed by modeling method of beam-column joint. To check the characteristics of vertical vibration, many tests and analyses were conducted on constructing building in Seoul. Results of tests and analyses were compared using transfer function. As a results, to check the vertical vibration characteristics, the cramp ratio of beam-column joint must be considered and reduced to 50% ~ 60% in structural design.

Before incorporating the earthquake-resistance design in design code(1988), most of existing residential buildings were built without having lateral resistance capacity in addition to their structural peculiarity such as exterior stair ways, exterior elevator room. For these reasons, the retrofitting research demands for existing buildings arise recently and many retrofitting methods are proposed. These tasks are irnportant to reduce the enormous economic loss and environmental issues. The objective of this study is to predict the perforrnance increase due to various strengthen schemes and suggest adequate strengthen methods for wall type apartment buildings not designed to resist earthquake.

The reinforced concrete wall type apartments built before 1988 in Korea, which are rarely seen in other countries, were constructed using tunnel form method for convenience of construction. Tunnel form method, however, do not arrange bearing walls in the direction of long side of the apartment, and this results in little resistance capability against lateral loads in that direction. Consequently, there exists significant collapse possibility due to the formation of plastic hinge at the joints of wall and slab during earthquake. This study experimentally investigates the reinforcement methods using carbon sheet and L-shaped steel which were not seismically designed. The reinforcement method using carbon sheet and L-shaped angle, has following advantages; construction workability, usage of light-weight material, and little requirement for the installation room. The specimen with steel bar fill up using modified epoxy mortar in the mid-span of the slab shows the same stiffness as the standard specimen without reinforcement and the stiffness of the specimen reinforced by carbon sheets without L-shaped steel was increased by only about 13%, implying that those existing methods cannot provide significant reinforcement effects. For the specimens of which wall-slab joints were reinforced using both carbon sheet and L-shaped steel, the increase of stiffness ranges from 43% to 496% and the increase of energy dissipation amount ranges from 120% to 233%. Also it was identified that the linkage method using penetration bolts was more efficient than the one using expansion anchors in increasing stiffness, strength and energy dissipation capacity.

Before incorporating the earthquake-resistance design in design code(1998), most of existing residential buildings were built without having lateral resistance capacity in addition to their structural peculiarity such as exterior stair ways, exterior elevator room. For these reasons, the retrofitting research demands for existing buildings arise recently and many retrofitting methods are proposed. These tasks are important to reduce the enormous economic loss and environmental issues. In this study, Scaled residential buildings with/without lateral resistance were tested and monitored with external lateral load especially toward the longer side of the building. From these experiments, enhanced retrofitting methods of old shear wall system are proposed and also compared with structural analysis.

Earthquake resistant design was introduced to Korea in 1988 for tall buildings, in 1992 for highway bridges and even earlier than that for nuclear power plants. The apartments designed by large unit housing planning was constructed by tunnel form method for the construction convenient in 1980. As a results, many structures without any seismic resistance capacity were built during the 80’s. In this paper, to improve the seismic capacity in wall-slab joint, experiments which improve and retrofit a seismic capacity by steel reinforcing, unequal angle bracing, carbon sheet attachment are carried out. These methods also are economic and simple in mitigating seismic hazard, improving earthquake-resistance performance, and reducing the risk level of building occupants. Consequently these methods were confirmed its effectiveness in improving the seismic performance were confirmed its effectiveness.

Earthquake resistance design has been developed many countries like Japan, USA, Mexico, New Zealand etc., which countries have experienced many earthquakes. Nowadays, earthquake resistance design has come into worldwide use. In Korea, the seismic design regulations have been established since 1988 in order to minimize the economic losses. Recently performance based design method has been adopted as a new Earthquake resistance design method. These regulations, however, are targeted for newly constructed buildings, In Korea, there are no regulations for existing buildings that built before 1988. On the other hand, in Japan and USA, the seismic performance evaluation is coded. In Japan, the evaluation index which can measure seismic performance has been made. So, we need to prepare the regulations that evaluate the seismic performance, furthermore proper retrofitting design guideline needs to be proposed when remodeling old buildings. In this research, various seismic performance evaluation methods which are being used in Japan and USA are reviewed in order to establish seismic performance evaluation index for those existing old structures in Korea.

This paper studied the efficiency of retrofitting of reinforced concrete structure which was not designed to endure an earthquake. The earthquake in Kobe, Japan showed that there was a great possibility of having an earthquake even in big city and the damages were concentrated on mid or low story buildings which were not considered to be protected from an earthquake. This experiment used reinforced concrete structure which restrained side-by-side displacement-to test durability against an earthquake. This study deals with the structural performance of reinforced concrete frame structures strengthened with steel materials.

Cu를 함유한 2종의 저합금 고장력강(HSLA-A, HSLA-B)? 기계적 성질에 미치는 시효처리의 영향을 조사하였다. 탄소량이 적음에도 불구하고 Cu첨가로 석출물을 생성시킴으로서 2합금 모두 650˚C에서 시효한 경우 양호한 강도(HSLA-A:Y.S 703Mpa, E.L 22.6% HSLA-B:Y.S 810 Mpa, E.L 23.8%)와 인성(HSLA-A:271.4J, HSLA-B:197.5J at -50˚C)의 조합을 나타내었다. 500˚C에서 시효할 때 가장 높은 항복 강도를 나타내나 인성은 아주 낮은 값을 나타내었다. 500˚C이상 시효 온도가 증가하면 강도는 감소하고 인성은 증가하였다. HSLA-B강의 강도가 HSLA-A 강보다 높은데, ?칭 상태에서의 강도 차이는 경화능을 증가시키는 원소인 Ni, Mn, Mo, Cu의 첨가량 차이에 의한 기지 조직의 차이에 의한 것이며, 시효한 상태에서의 강도 차이는 기지 조직과 석출 강화에 기여하는 Cu량의 차이에 의한 것으로 판단된다. 시효 경화 곡선에서 700˚C에서의 경도 증가는 오스테나이트-페라이트 2상 영역으로부터 냉각시 생성된 “M-A constituents”에 의한 것이다. HSLA-A강과 HSLA-B강의 충격 천이 온도는 각각 -125˚C와 -145˚C이었다.

본 연구에서는 기계식 후설치앵커 중 비틀림 제어 확장 앵커를 비균열콘크리트에 설치한 것으로 연구범위를 국한하고, 슬리브와 헤더를 개선한 국내 A사의 앵커를 시험대상으로 선정하여 콘크리트 강도와 앵커의 유효 묻힘깊이에 따른 단일앵커에 대한 인발시험을 수행하였다. 시험결과를 나타낸 것으로 모든 시험체 군에서 변동계수 15%이내의 성능을 나타내었고 이러한 결과로 볼 때 후설치앵커의 성능은 만족하고 있는 것으로 판단된다.

이 연구에서는 현실적이고 유의미한 내진보강비용 산정하기 위해 실제 내진보강 사례를 기반으로 통계분석을 수행하여 건축물의 노후도와 연면적을 고려한 보다 현실적인 내진보강 비용을 추정하는 연구를 수행하였다. 데이터 베이스를 기반으로 노후도에 따라 연면적 대한 내진보강비용을 통계적으로 분석하여 이를 정규화하였고, 역으로 연 면적과 준공연도를 가지고 내진보강공사비용을 역추산할 수 있는 방법을 제안하였다.. 지속적인 내진보강 사업 사례의 빅데이터화가 이루어지면 정확성이 높은 내진보강 비용 산정이 실현될 것으로 판단된다.

구조물의 내진보강의 필요성이 대두되고 있지만 이를 담당하는 기관이나 사람은 내진구조 비전공자로 효과적으로 내진보강사업을 발주 및 관리, 감독하는데 어려움이 있다. 이러한 문제점을 해결하기위해 분석적 계층화 프로세스를 이용하여 보강대상 건축물의 내진보강공법 우선순위를 제안하는 프로그램을 개발하였다. 이를 통해 담당자는 구조물별, 내진성능 부족요인 별 최적의 내진보강공법을 선정할 수 있을 것으로 기대된다.

본 연구에서는 캐스트 인 채널의 반복가력 시험을 수행하고 그 성능을 평가하였다. 반복가력 시험결과, 1,111,111번 동안 콘크리트 파괴 및 캐스트 인 채널 파괴는 발생하지 않았다. 또한, 캐스트 인 채널의 인발강도를 반복가력 시험 전․후로 나누어 평가한 결과 최대하중 차이는 1.5kN로 나타나 매립형 찬넬의 내구성 및 안전성은 확보된 것으로 판단된다.