PURPOSES: Recently, crack, rutting, and stripping problems from the surface of asphalt pavements in National highway are observed and they affect the drivers to feel uncomfortable on the road. Surface treatments are recommended to use in distressed pavements due to costeffective, and improvement of surface performance. The purpose of this study is to evaluate the performance of micro-surfacing and polymer slurry seal treatments for distressed asphalt pavements. METHODS: Surface conditions and friction resistance are evaluated for asphalt pavements treated with micro-surfacing and polymer slurry seal mixes in National highway 30 line and 34 line. Visual observation is conducted and surface performance is measured by PES (Performance Evaluation Surveyor) in terms of crack ratio, rutting and IRI(International Roughness Index). BPN(British Pendulum Number) is measured by BPT(British Pendulum Tester) to evaluate the friction resistance in the field. RESULTS: The surface evaluation results are presented for asphalt pavement treated with micro-surfacing and polymer slurry seal treatments in National highway 30 line and 34 line. Based on the visual observation, micro-surfacing and polymer slurry seal treatments show better improvements in terms of cracks and stripping. Based on the surface conditions measured by PES vehicle, the surface performance of microsurfacing treatments improves from 53.3% to 54.2% and the surface performance of polymer slurry seal treatments improves from 21.6% to 59.7%. However, the friction resistance of both micro-surfacing and polymer slurry seal treatments decreases from 2.5% to 6.7%. Further, it should be verified to produce the surface exposed with aggregates during the construction process of both treatment methods in the field. CONCLUSIONS : Based on the performance evaluation results in the filed, the surface performance of asphalt pavement treated with micro-surfacing and polymer slurry seal treatments improves from 21.6% to 59.7%. While, the friction resistance of asphalt pavement treated with micro-surfacing and polymer slurry seal treatments does not improve. It can be concluded that current micro-surfacing and polymer slurry seal treatments would improve surface performance but would not improve the friction resistance.

화장료의 UV 차단과 은폐효과를 갖는 이산화티탄을 사용하여 자기조직체 형성공법을 적용한 하이브리드 이산화티탄을 제조하고 형태, 성질, 공정의 최적조건과 자외선차단 개선을 확인하였다. 하이브리드 이산화티탄은 마이크로 이산화티탄(250~300nm)의 표면에 나노 이산화티탄(20~30nm)을 자기조직체 형성공법을 이용해 결합시킨, 이산화티탄 대 이산화티탄의 결합체를 말한다. 하이브리드 이산화티탄 제조의 최적조건을 알아내기 위해 (-)을 띄는 마이크로 이산화티탄의 표면에 양이온의 링크로써 AlCl3 를 농도별로 조정하고, 그에 따른 마이크로와 나노 이산화티탄의 투입비율을 달리하여 각각의 조건에서 만들어진 시료를 광학분석, 입도분석, 전위차분석 등을 이용해 확인하고 최적의 제조 조건을 알 수 있었다. 최적의 제조 조건에서 만들어진 하이브리드 이산화티탄의 자외선차단 상승효과를 확인하기 위하여 하이브리드 이산화티탄이 첨가된 화장료와 사용된 하이브리드 이산화티탄과 같은 비율의 마이크로와 나노 이산화티탄을 첨가한 화장료의 SPF in-vitro 를 측정하였고, 15%내지 30%의 자외선차단 상승 효과를 확인하였다.

PURPOSES : The purpose of this article is to compare and evaluate the riding comfort of a passenger in tunnels depending on different surface textures of concrete pavement. METHODS: Evaluation of riding comfort is conducted at 17 sections, which have different surface texture such as transverse tinned(TT), longitudinal tinned(LT) and diamond grinded(DG). A triaxial accelerometer was set up on the passenger seat surface of the test vehicle to measure vibrations of an occupant, then the effects of vibration on comfort and health were evaluated by ISO 2631. And microphones were installed at passenger's ears height to measure sound pressure level(SPL) in the test vehicle. Additionally, a surface microphone was installed on the inside of wheel arch to evaluate noise between tire and pavement by NCPX method. All tests were conducted cruising at 100km/h. RESULTS : The results of all tests are as follows. First, both vibration magnitudes for comfort and for health in LT and DG sections are almost same and they represent lower than those in TT sections. Second, the average SPL of DG shows the lowest decibels among them. And third, it is founded that interior noise is significantly affected by noise between tire and pavement. CONCLUSIONS : It may be concluded that DG can provide more excellent riding comfort to passenger than LT or TT. Therefore, it is necessary to consider applying DG to existing pavement surface to improve surface condition when the driving environment especially requires riding comfort like a long tunnel.

When we excavate an underground to build basement, the ground anchors are needed to prevent collapse of neighboring ground, subsidence and movement. Ground anchor construction required shore sheet piles, wales and struts as to maintain secure excavation. Existing box-type bracket using head part of ground anchor can not be possibly adjustable to the boring angle because the brackets are manufactured with unified angle in a factory. Also, box-type brackets have imperfection and instability caused by inequable force. In this study, a new bracket system is proposed. The bracket's side plate is reinforced and the angle of boring can be controlled. To investigate the structural performance of presented brackets, FEM analysis has been performed by using ANSYS commercial program. As a result, this bracket shows sufficient stability for all angle case and the strength is increased about 24% than existing bracket.

PURPOSES : This study aims at proposing the methodology for benefit evaluations in pavement maintenance methods and timings using KoPMS(Korean Pavement Management System) software which was developed for efficient pavement management. METHODS : This study classified pavement sections into 4 clusters considering AADT(Annual Average Daily Traffic) and ESAL(Equivalent Single-Axle Load) using cluster analysis and used the deterioration models in each cluster. Increased user costs due to pavement deterioration as time goes by and agent costs for maintenance were estimated. Based on deterioration model and KoPMS software, Methodology for benefit evaluation was proposed in pavement maintenance methods and with/without implementation using real pavement section data. RESULTS : This study verified that considering agent costs only would be constrained to decide pavement maintenance methods and timings, and ascertained that decision making with agent and user costs would be effective. In addition, this study revealed that pavement maintenance methods and timings can be affected by AADT and ESAL and frequent pavement maintenances can be more efficient for benefits in pavement sections with more AADT and ESAL. Also this study found that user costs would be more affected to decision making than agent costs. Moreover, Delay of conducting pavement maintenance caused increased vehicle operating costs and environmental costs because of poor conditions of pavements. CONCLUSIONS : This study proposed LCCA and benefit estimation methodology of pavement with considering agent and user costs. The results of this study can be used for baseline data of efficient pavement asset management.

현재 우리나라 고속도로의 60%이상을 차지하는 콘크리트 포장은 공용수명의 도달로 인해 보수를 필요 로 하는 구간이 증가하고 있다. 노후된 콘크리트 포장은 단면보수 등 부분적 보수가 진행되어 왔으나 이 또한 한계에 이르러, 전면보수를 필요로 하는 구간이 증가되고 있다. 노후 콘크리트의 전면보수 방법으로 아스팔트 덧씌우기가 주로 사용되고 있지만, 기존 콘크리트 포장 줄눈부에서 유발되는 반사균열 및 기존 포장과의 부착력 부족으로 발생되는 포트홀 등의 문제가 발생하여 덧씌우기된 아스팔트 포장의 수명을 단축하는 요소로 평가되어왔다. 아스팔트 덧씌우기 구간의 반사균열 문제를 해결하기 위해 제안된 Saw and Seal 공법은, 덧씌우기된 아스팔트 포장에 기존 콘크리트 포장의 줄눈과 동일한 위치에 줄눈을 시공하여 반사균열을 제어하는 공법 이다. 하지만 주입식 줄눈재를 사용한 기존의 Saw and Seal 공법은 줄눈부의 차수기능 미흡에 따른 2차 균열 등의 포장결함과 신․구 포장간의 부착력 미흡에 따른 포트홀 문제등의 문제를 해결하지 못하였다. 기존 Saw and Seal 공법의 문제를 해결하고자 개발된 ‘노후콘크리트 포장 줄눈 아스팔트 덧씌우기 공 법’은 Water-blasting과 진공흡입 청소의 표면처리 공정을 통해 절삭 잔재물 및 열화부의 완전한 제거를 가능하게 하여 기존 포장과 아스팔트 덧씌우기 포장의 3.5배 증대된 부착력을 바탕으로 포트홀 발생을 억제하고 , 접착식 중공 성형 줄눈재의 사용으로 유도된 반사균열을 효과적으로 제어하고 더불어 줄눈을 통한 수분침투를 방지하여 2차 파손을 억제하는 것을 특징으로 한다. 개선된 ‘노후콘크리트 포장 줄눈 아스팔트 덧씌우기 공법’은 포장가속시험 및 접착제의 허용변위 시험, 노화시험, 줄눈재의 차수기능 시험 등을 통해 성능을 검증하였으며, 경기도 가평의 국도 37호선 봉수교차로에 2011년 6월 시험시공을 실시하였다. 본 연구에서는 추적 조사를 통하여 국도 37호선 봉수교차로에 시공한 개선 공법 구간 및 동일시기 시공 된 화현, 일동 교차로의 주입식 줄눈재가 적용된 기존 Saw and Seal 공법의 줄눈부 비교를 통해 ‘노후콘 크리트 포장 줄눈 아스팔트 덧씌우기 공법’의 장기 공용성을 평가하였다. 본 연구의 봉수교차로 줄눈부의 이력조사는, 시공 전과 시공 단계에 따른 줄눈부 변화, 시공 직후, 1년 공용 뒤, 동절기의 줄눈부(20개월 공용 뒤), 2년 공용 뒤의 줄눈부의 변화를 추적조사를 통해 실시하였 다. 인근 교차로의 주입식 줄눈재 Saw and Seal 구간 줄눈부 조사는 봉수 교차로 조사시기와 동일한 날 짜에 진행되어 두 구간의 줄눈부 상태를 비교하였다. 평가 결과 개발 공법 구간의 줄눈부는 공용후 2년간의 추적조사 기간 동안 시공초기와 같이 양호한 상 태를 보였으나, 주입식 줄눈재 사용구간에서는 2차 균열을 비롯한 백태 현상, 줄눈재 손상등의 포장결함 이 발생하였다.

There are a number of construction methods to build spatial structures such as erection method, Element method, Block method, Sliding method, Lift-up method and Push-up method. These methods are uneconomical and low accuracy, and require long construction duration because of a need of a scaffold or a tower crane to build spatial roof frame. In this study, the construction method to erect a truss structure was proposed as an economical and easy installation method. The proposed method has end hinges of keel truss and winches with horizontal cable. This method makes safe and accurate production and reduces construction duration because trusses are built on the floor or supporter. The goal of this study is to verify the validity of construction method by building scale model using the proposed method.

PURPOSES : The PMS(Pavement Management System) has been utilized in order to efficiently allocate the limited budget for the maintenance of national highway system. In the PMS of national highway, surface pavement condition is evaluated by using the VI (Visual Index). However, the VI is determined only by considering the cracking rate (%) and rut depth (mm), which is not reflecting the IRI (International Roughness Index) that is known as an important factor of pavement performance. In this study, the NHPCI (National Highway Pavement Condition Index) which includes the cracking rate (%), rut depth (mm), and IRI (m/km) is suggested for determining the rehabilitation methods group. METHODS : First, the rehabilitation methods performed between 2008 and 2010 on the national highway is classified and then, NHPCI is determined for each rehabilitation method. Next, the NHPCI for each rehabilitation method is grouped through the interval estimation of the population mean and T-test analysis. RESULTS : According to NHPCI range, the rehabilitation methods are divided into four categories: Not Required, Preventive Maintenance, Overlay Treatment (with or without cutting), and Full-scale Treatment (i.e., reconstruction). CONCLUSIONS : Based on this study, it is recommended that the appropriate NHPCI range should be determined through the combination of the rehabilitation categories and Decision Procedure of Pavement Distress Condition Visual Index.

The large-space single-layer lattice dome is relatively simpler in terms of the arrangement of the various framework members and of the design of the junction than the multi-layered lattice dome, can reduce the numbers and quantity of the framework members, and has the merit of exposing the beauty of the framework as it stands. The single-layer lattice dome, however, requires a stability investigation of the whole structure itself, along with an analysis of the stress of the framework members, because an unstable phenomenon called "buckling" occurs when its weight reaches critical levels. Many researchers have systematically conducted researches on the stability evaluation of the single-layer lattice dome. No construction case of a single-layer lattice dome with a 300-m-long span, however, has yet been reported anywhere in the world. The large-space dome structure is difficult to erect due to the gigantic span and higher ceiling compared with other common buildings, and its construction cost is generally huge. The method of erecting a structure causes major differences in the construction cost and period. Therefore, many researchers have been conducting various researches on the method of erecting such structure. The step-up method developed by these authors can reduce the construction cost and period to a great extent compared with the other general methods, but the application of this method inevitably requires the development of system supports in the center section as well as pre-existing supports in the boundary sections. In this research, the safety during the construction of a single-layer lattice dome with 300-m-long span using pre-existing materials was examined in the aspect of structural strength, and the basic data required for manufacturing the supports in the application of the step-up method developed by these authors during the erection of the roof structure were obtained.