국내 도로 연장은 2023년 기준 115,878km로 매년 증가하는 추세를 보이고 있다. 이중 준공 30년 이상된 노후도로의 비율은 51.5%에 해당하고 있어 도로 유지관리의 중요성이 대두되는 실정이다. 본 연구에서는 아스팔트 예방적 유지보수공법인 포그씰(Fog Seal)을 실 제 공용중에 있는 도로에 적용하여 공용성 변화를 분석하였다. 공용성능 분석을 위해 차량의 휠패스 부분에서 공법당 6개의 코어를 3 차년간 채취하여 공극률 및 바인더 함량 값을 비교하였다. 분석 방법으로는 포그씰 공법을 시공하지 않은 구간을 대조군으로 선정하 여 추적조사 기간에 따른 변화 추이를 분석하였다. 분석 결과, 공극률은 포그씰 시공 이후 지속적인 감소를 보였다. 바인더 함량의 경 우 공용연수가 증가할수록 바인더 함량 또한 점차 증가하는 것으로 확인되었다. 이는 공용연수가 증가함에 따라 차량의 주행으로 인 해 표면에 도포된 포그씰이 점차 도로 표면 및 균열 속으로 스며들어 내부의 공극이 채워지는 것으로 판단된다.

PURPOSES : The purpose of this study is to provide basic data to improve the service life of asphalt pavement using basalt aggregate in Jeju Island by evaluating the performance of asphalt pavement through analysis of material and structural aspects. METHODS : To evaluate the performance of Jeju Island's asphalt pavement, cracks, permanent deformation, and longitudinal roughness were analyzed for the Aejo-ro road, which has high traffic and frequent premature damage. Cores were collected from Aejo-ro sections in good condition and damaged condition, and the physical properties of each layer were compared and analyzed. In addition, plate cores were collected from two sections with severe damage and the cause of pavement damage was analyzed in detail. RESULTS : About 45% of the collected cores suffered damage such as layer separation and damage to the lower layer. The asphalt content of surface layer in the damaged section was found to be 1.1% lower on average than that in the good condition section, and the mix gradations generally satisfied the standards. The density difference between the cores of each layer was found to be quite large, and the air voids was found to be at a high level. CONCLUSIONS : Test results on the cores showed that, considering the high absorption ratio of basalt aggregate, the asphalt content was generally low, and the high air voids of the pavement was believed to have had a significant impact on damage. High air voids in asphalt pavement can be caused by poor mixture itself, poor construction management, or a combination of the two factors. Additionally, the separation of each layer is believed to be the cause of premature failure of asphalt pavement.

PURPOSES: This study was conducted to investigate the causes of damage and to suggest proper repair methods for the sections in which a number of transverse cracks and faulting occurred in JCP (Jointed Concrete Pavement) slabs during the early-age performance period. METHODS: Field crack survey, FWD (Falling Weight Deflectometer) investigation, dowel bar installation condition survey, longitudinal profile survey, and in-situ core specimen inspection were conducted. . RESULTS : As a result of the analysis, it was found that there was no decline in the composite modulus of the subgrade reaction (k-value). The dowel bars were properly installed, but the LTE (Load Transfer Efficiency) of the joint and transverse cracks were analyzed to be very low. In addition, it was found that there are voids in the bottom of the slab at the joints and corners. Due to the excessive built-in curling in the early age of concrete pavement construction, upward curling displacement occurred at the joints and corners, resulting in voids at the bottom of the slab. As a result, it was found that transverse cracks occurred due to the defective joint LTE. CONCLUSIONS: Excessive built-in curling can cause early age cracks in the JCP slabs. In order to minimize the occurrence of reflection cracks after the application of the asphalt overlay in the future, concepts of alternative repair methods were proposed.

PURPOSES: The purpose of this study was to develop an urgent road-repair system and perform a field applicability test, as well as discover the optimum mix design for machine applications compared to the optimum mix design for lab applications. METHODS: According to reviews of the patent and developed equipment, self-propelled and mix-in-place equipment types are suitable for urgent pavement repair, e.g., potholes and cracks. The machine-application mix design was revised based on the optimum lab-test mix design, and the field application of a spray-injection system was performed on the job site. The mixture from the machine application and lab application was subjected to a wet-track abrasion test and a wheel-tracking test to calibrate the machine application. RESULTS and CONCLUSIONS : This study showed that the binder content could differ for the lab application and the machine application in the same setting. Based on the wet-track abrasion test result, the binder contents of the machine application exceeded the binder contents of the lab application by 1-1.5% on the same setting value. Moreover, the maximum dynamic stability value for the machine application showed 1% lower binder contents than the maximum lab-application value. Collectively, the results of the two different tests showed that the different sizes and operating methods of the machine and lab applications could affect the mix designs. Further studies will be performed to verify the bonding strength and monitor the field application.

PURPOSES:In this study, field performance evaluation of crack treatment of pavement and the feasibility of surface treatment of pavement are presented. The performance and cost of preventive maintenance methods have been previously verified, and the methods are being used in many developed countries and cities. However, the performance and cost of the system have not been verified in domestic, field applications. Therefore, in order to improve performance, the field performance is evaluated, and a reasonable cost is proposed.METHODS:Visual Inspection was conducted to evaluate the field application and performance of the preventive maintenance method. In addition, the PCI index was calculated from the results of visual inspection of the application area of the surface treatment method, and the performance life of each method was predicted. For the economic evaluation, life cycle cost analysis was performed using the life cycle cost analysis program.RESULTS:In order to evaluate and quantify the field performance of crack repair material, the residue condition of the pavement surface after crack treatment, rather than the performance of the material, is evaluated. In addition, the crack resistance and performance life of surface treatment methods are evaluated. The cost of currently available treatment methods are compared to the common pavement cut and overlay method, and it is determined that the preventive method is not economical based on life cycle cost analysis.CONCLUSIONS:Because of the characteristics of cracking, it is necessary to conduct the evaluation of currently applied methods and the analysis of the cause of damage, by visual inspection. Moreover, in order to evaluate the performance and economic suitability of the currently applied surface treatment methods, it is necessary to acquire information on application sections by monitoring their long-term conditions and performance.

PURPOSES: Performance evaluation of four types of asphalt concrete overlays for deteriorated national highways. METHODS : Pavement distress surveys for crack rate and rut depth have been conducted annually using an automated pavement survey vehicle since 2007. Linear and non-linear performance prediction models of the asphalt concrete overlays were developed for 43 sections. The service life of the asphalt overlays was defined as the number of years after which a crack rate of 30% or rut depth of 15mm is observed. RESULTS: The service life of the asphalt overlays was estimated as 17.4 years on an average. In 90.7% of the sections, the service life of the overlays was 15 years or more which is 1.5 times the life of conventional asphalt concrete overlays used in national highways. The performance of the overlays was dependent on the type of asphalt mixture, traffic volume levels, and environmental conditions. CONCLUSIONS : The usage of stone mastic asphalt (SMA) and polymer-modified asphalt (PMA) for the overlays provided good resistance to cracking and rutting development. It is recommended that appropriate asphalt concrete overlays must be applied depending on the type of existing pavement distress.

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.

This study examined the growth performance and field evaluation of the dual herbicide-resistant transgenic creeping bentgrass plants. The effect of glyphosate treatment on the herbicide resistance of the transgenic creeping bentgrass plants was determined, and the non-transgenic control plant withered at the concentration 11 μg/mL or higher whereas the transgenic creeping bentgrass plants survived the treatment at the concentration of 3,000 μg/mL, and the increase of the plant length was repressed as the glyphosate treatment concentration was increased. At field evaluation, glufosinate-ammonium and glyphosate were simultaneously treated to investigate the weed control effect. The results showed that more than 90% of the weeds withered four week after herbicide treatment, while the transgenic creeping bentgrass plants continued to grow normally. Therefore, the dual herbicideresistant creeping bentgrass plants may be able to greatly contribute to the efficiency of weed control and to the economic feasibility of mowing in places such as golf courses.

PURPOSES : The purpose of this study is to evaluate of field application and laboratory performance of warm-mix asphalt (WMA) according to the dosage rate of organic-based WMA additive. METHODS: Three asphalt mixtures, i.e., hot mix asphalt (HMA), WMA with the dosage rate of 1.5%, WMA with the dosage rate of 1.0%, were sampled from the asphalt plant when the field trial project were constructed. With these mixtures, the laboratory testings were performed to evaluate the linear viscoelastic characteristics and the resistance to moisture, rutting and fatigue damage. RESULTS : From the laboratory test results, it was found that the WMA with the reduced dosage rate of additive would be comparable to HMA and WMA with the original dosage rate in terms of the dynamic modulus, tensile strength ratio, rutting resistance. However, the fatigue reisistance of WMA with the reduced dosage rate was slightly worse but it should be noted that the fatigue performance is necessarily predicted by combining the material properties and pavement structure. CONCLUSIONS: Through the field construction and laboratory testings, the dosage rate of organic-based WMA additive could be reduced from 1.5% to 1.0% without the significant decrease of compactability and laboratory performance. The long-term performance of the constructed pavement will be periodically monitored to support the findings from this study.

PURPOSES : This study evaluated the field applicability and laboratory performance of warm-mix asphalt (WMA) as an alternative technology in asphalt pavement. METHODS : The pilot road using two different types of WMA mixture and one HMA mixture was constructed in Waegwan-Seokjeok road construction site and the mixtures were sampled at the asphalt plant for laboratory testings. The field applicability was assessed in environmental aspects, such as CO2 emission, and in aspects of constructibility using the existing equipment and procedure, i.e., thickness and density measurement. The laboratory testings included the moisture susceptibility test by AASHTO T283, dynamic modulus test, triaxial repeated load permanent deformation test, and the fatigue test. RESULTS : The temperatures for production and compaction of WMA were 20~30℃ lower than those for HMA and therefore, the noxious gas emission were significantly reduced. The field density of WMA pavements was similar or better than that of HMA pavement. From the laboratory testings, it was found that WMA mixtures exhibit comparable performance to HMA mixture in moisture susceptibility, permanent deformation, and fatigue performance. CONCLUSIONS : With these results, it would be concluded that WMA could replace the existing HMA technology without any significant issue. To support this conclusion, it is necessary to track the long-term performance of WMA in pilot road.

본 연구에서는 도심지 열섬현상을 완화 시킬 수 있는 아크릴 수지와 차열안료를 혼합한 차열성 포장을 개발하였다. 태양 복사열에 의한 포장체의 온도상승을 모사한 실내 시험으로부터 60℃의 포장 온도에서 차열성 포장이 12℃ 이상의 온도 저감 효과를 나타냈다. 이러한 온도 감소 효과는 차열안료의 배합비가 증가함에 따라 증가하였고, 반면에 점도의 증가로 인하여 작업성은 떨어졌다. 이러한 결과로부터 아크릴 수지 대비 차열안료의 최적혼합비율을 15%로 결정하였다. 차열성 포장의 칸타브로 손실률은 일반 배수성 포장의 손실률 1/4 수준으로 골재 비산 저항성이 우수하게 나타났다. 휠트랙킹 시험결과 차열성 포장의 동적안정도가 일반 배수성 포장에 비해 두 배 증가하였다. 차열성 포장재의 높은 부착력으로 인하여 탈리에 의한 손상 가능성은 낮은 것으로 나타났다. 시험 시공 구간에서의 소음도 측정 시험 결과 일반 배수성 포장에 비하여 평균 3.7dB의 소음저감 효과가 있었고, 미끄럼 저항치는 일반 배수성 포장에 비해서 평균 30% 정도 높아 우수한 미끄럼 저항성을 가지는 것으로 판단된다. 투수 시험 결과 차열성 포장의 투수성은 일반 배수성 포장보다 다소 작았으나 국내 배수성 포장 기준을 만족하는 것으로 나타났다.

In order to verify the strength of slurry shotcrete compared to existing shotcrete, The results were analyzed and evaluated.

국가직무능력표준(National competency standards, NCS)은 산업현장에서 직무를 수행하기 위해 요구되는 지식, 기술, 태도 등의 내용을 국가가 체계화한 것이다. NCS기반 현장중심 교육과정을 적용한 방사선과 재학생 3학년을 대상으로 일반촬영에 대한 방사선사 직무수행도를 평가하였다. 평가 결과, 모든 촬영방식에서 우수 및 충족 비율이 93% 이상으로 현장중심 교육과정이 재학생의 직무수행도 향상에 긍정적인 영향을 끼친 것으로 판단된다. CR 방식은 전체적으로 가장 우수한 평가를 받았으나 대상자 간 편차가 크고 영상기기조작능력이 부족한 것으로 평가되었고 Film 방식은 노출조건 설정 및 현상작업이 문제점으로 평가되었다. DR 방식은 우수한 평가를 받았으나 영상기기조작능력, 부속기자재운영능력이 부족한 것으로 평가되었다. 각 촬영에서 성취수준 이하의 평가요소를 교과목 운영에 보완한다면 재학생의 학업성취도 향상뿐만 아니라 졸업 후 임상에서 방사선사 직무수행도 향상에 도움이 되리라 판단 한다.

In this study, the field construction with the prefabricated lightweight plastic foundation using recycled plastic forsewage pipeline and triple wall PE sewer pipe was carried out to verify the construction workability of prefabricated plasticfoundation and deformation resistance potential of triple wall PE sewer pipe. The construction procedure in field wasfollowed the KS standard. The measured vertical deformations of PE pipe are average 2.35mm which means around 1%of deformation for 300mm diameter of PE pipe. Judging from the type of foundation, the use of plastic foundation (CaseB & Case C) showed lower deformation due to differential settlement than that of sand bedding foundation. Especially,the plastic foundation made a relatively uniform deformation of PE pipe. However, the sand foundation represented thenon-uniform deformation of PE pipe.

In this research, we evaluate the workability of 100 MPa concrete for CFT column thru Batch plant test. Also, we evaluate the fire resistance performance of steel composite column.

In this study, an automated cable non-destructive test (NDT) system was proposed to monitor the steel cable. Magnetic Flux Leakage (MFL) method was applied for the cable inspection. A multi-channel MFL sensor head was fabricated using Hall sensors and permanent magnets. A wheel based Cable climbing robot was used to improve the accessibility to cable. In addition, remote data transmission and robot control were possible by applying the Wireless LAN communication. Finally, developed element techniques were integrated to MFL based Cable Climbing NDT system, and the field applicability of the integrated cable NDT system was verified through a field test.

To introduce how to design the shear wall for compression field theory, and to secure the strength of shear wall by using Prestressing element, to control at working load condition. also to evaluate the performance of shear wall's capacity.

최근 들어 온실 가스 감축을 위한 국제적 논의가 활발히 진행 중에 있으며, 탄소배출량 규제는 환경개선 이외에 산업·경제 분야에 중요한 영향을 미치면서 탄소 배출권 거래시장을 형성하였다. 이에 따라 도로 포장분야에도 국내외적으로 CO2 및 유해가스 배출량을 줄이기 위한 새로운 포장공법과 재료들에 대한 개발의 연구가 진행되고 있는데, 이중 생산 및 포설온도를 약 30℃ 낮추어 CO2 및 유해가스 배출량을 감소시키는 중온 아스팔트 포장공법이 있다. 본 연구에서는 시공된 중온 아스팔트 포장의 현장시험을 통해 장기 공용성을 평가하고자 공용초기에 1차 측정을 수행하고, 약 11개월경과 후에 2차 측정을 수행하고 비교분석하였으며, 그 결과 11개월 후에도 양호한 평탄성을 나타냈고 미끄럼 저항은 BPN 60.1으로 안전 기준에 만족하는 것을 확인하였다. 소성변형 측정 결과 버스 정류장 앞과 교차로 정지선 부근의 포트홀 발생 지점을 제외하고는 전체적으로 양호한 상태였으며 균열은 발생하지 않은 것으로 보아 섬유의 사용에 따른 혼합물의 인성과 균열 저항성이 향상된 것으로 판단된다.