캄보디아 해외 시범사업을 통한 아스팔트 포장 품질관리 사례

임재규 한국아스팔트학회 2022 한국아스팔트학회지 Vol.12 No.1

By comparing and evaluating the physical properties of asphalt road pavement in Cambodia and Korea, Cambodian companies will use it as basic data for future efficient management such as road pavement design, quality and maintenance management. The purpose of this study was to examine the pavement status of Cambodia’s asphalt roads through quality control cases based on overseas demonstration projects. The thickness of the asphalt layer was thinner and larger than that of Korea. on the other hand, density is generally similar. Deformation strength test results showed that neither surface layer nor base layer corresponded Korean standards. Marshall stability, flow, retained stability, indirect tension, tenacity, and tensile strength ratios were corresponded Korea’s quality standards, but not enough. The performance analysis of the asphalt core specimens showed that the overall quality standards of Korea were satisfied. However, As the thickness of the asphalt layer is rather thin and the variation is severe, it is necessary to thoroughly manage the construction and the quality fluctuation due to the thickness difference of the surface layer and the base layer will be serious.

국내적용 온도보정처짐개발식을 통한 배수성포장 분석절차 제안

최준성,오승훈,김장락,이종섭 한국아스팔트학회 2023 한국아스팔트학회지 Vol.13 No.2

In this study, we reviewed the applicability of the existing Temperature-compensated deflection equation using a Representative temperature estimation method using existing research results, and improved and verified it to a domestically new temperature- compensated deflection equation that takes into account various asphalt thicknesses. In addition, based on the FWD test-data of porous asphalt pavement, we propose a analyzing process for the performance degradation of porous asphalt pavement, including a process of performing standard load and temperature correction on FWD data, and a conversion process of FWD Back-calculation elastic modulus to field dynamic elastic modulus. After proposing the process, a Excel program was developed for the evaluating the degradation of performance in the porous asphalt pavement using the concept of dynamic elastic modulus.

재활용비율에 따른 순환아스팔트 혼합물의 절대점도, GPC 및 PG 판정온도를 이용한 회생수준평가

김원배,김우현,김영삼,김광우 한국아스팔트학회 2023 한국아스팔트학회지 Vol.13 No.2

The reclaimed asphalt pavement (RAP) should be properly rejuvenated when it is used in a recycled asphalt mixture. In this study, a RAP was used for recycled mix with recycle ratios of 30, 40 and 50 wt. % without rejuvenator. A 19 mm virgin aggregate for binder-course mixes, and a PG58-22 asphalt were used for recycled mixes, and a PG64-22 was used for a normal (control) mix. The asphalt binders were recovered from the RAP, normal mix and recycled mixes by Abson method. Absolute viscosity at 60°C, kinematic viscosity at 135°C, PG grading, G*/sin  and pass/fail (P/F) temperatures were measured from the recovered binders by a dynamic shear rheometer (DSR). Gel-permeation chromatography (GPC) was used to measure large molecular size (LMS) of binder from the dissolution of mixture particle without binder recovery for estimation of physical properties of asphalt. The recovered binder properties including absolute viscosity (AV), G*/sin  and P/F temperature were found to be increased by the recycling ratio increases. The regression analyses between AV and LMS, and P/F temp. and LMS showed high correlations with R2 > 0.99, respectively. Therefore, it was possible to estimate AV and P/F temp. reliably by LMS. According to Korean guide-line, recycled mixes failed to pass the limit of AV ≤ 5,000 p except for 30% recycled mix. However, all recycled mixes should be prepared using a rejuvenator when evaluated by P/F temp. method of the Asphalt Institute method, because the P/F temp. of recovered binders were 6°C on average higher than expected values.

라테라이트로 구성된 라오스 비포장도로의 품질 향상을 위한 개선공법의 적정치환두께 연구

강일환,김용주,권홍준 한국아스팔트학회 2023 한국아스팔트학회지 Vol.13 No.2

The main roads in Lao PDR are unpaved and made of laterite, which has the disadvantage of reducing bearing capacity during rainy season or squalls and causing soil and sand to flow out. In this study, the appropriate replacement thickness of three types of improvement methods (CTB, ATB, and Lean Con'c) was calculated through computer analysis to improve the quality of unpaved roads in Laos, which are mainly composed of laterite. As a result of engineering classification by sampling the soil of the unpaved road, A-2-7 (High-plasticity silts) according to the AASHTO classification and SP, CL, and ML according to the USCS classification were obtained. Based on engineering classification, the condition of unpaved roads was divided into 5 types (SP, SM, very stiff clay (dry season), medium clay, and very soft clay), and computerized analysis was performed in FLAC 3D using the HL-93 truck tandem model. was carried out. As a result of computer analysis, it was confirmed that the maximum deflection decreases according to the replacement thickness of the improved method. In the case of ATB, horizontal and vertical strains (εt,εz) were calculated to be the largest in all conditions. In the case of Lean Con’c, the horizontal strain and vertical strain were calculated to be the smallest in all conditions, and the amount of change according to replacement thickness was the smallest. As a result of calculating the appropriate replacement thickness in the upper layer of unpaved roads in all conditions, it is 10 to 20 cm for CTB, more than 20 cm for ATB, and 5 to 10 cm for Lean Con’c

기존 설계사례 분석을 통한 항만 화물자동차 주차장 설계방법론에 관한 연구

최준성,진현호,이재진,홍성현 한국아스팔트학회 2022 한국아스팔트학회지 Vol.12 No.2

In recent years, the conflict between the port authority and nearby residents due to the chronic illegal parking problem on the road near the port is getting worse. This is one of the factors that adversely affect the long-term road pavement performance. The parking supply problem in the port hinterland is due to the gap between the actual demand for parking lots and the calculation formula used in designing the parking lot. To solve this problem, this study presents a design methodology when designing a parking lot in a port by examining and analyzing on the existing design method problems and actual design examples of parking lots in the port hinterland. Through the methodology presented in this study, it is believed that more logical design can be implemented than past design cases when designing the parking lot for cargo vehicles in the hinterland of the port, and pavement performance of roads near the port can be increased due to reduction of illegal parking near the port through estimation of the appropriate number of parking surfaces.

노후 콘크리트 포장의 내구성, 시공성, 유지관리성을 고려한 아스팔트콘크리트포장 리모델링 검토 사례연구

지화식 한국아스팔트학회 2022 한국아스팔트학회지 Vol.12 No.1

Currently, the applied remodeling method for concrete pavement, which is more or less than 20 year of performance period varies project by project, due to the absence of the standard design guideline on concrete pavement (cutting/non-cutting and overlay). This study aims to establish remodeling methods for aged concrete pavement according to its site pavement damage conditions, using the design case study, research data, and papers from projects procured by Korea Expressway Corporation. The study found that the overlay method without cutting was advantageous in terms of durability, workability, etc. and that the overlay thickness of 10 cm, was useful for reducing cost and suppressing reflection cracks. The study also surveyed damage level of the existing concrete pavement and determined the corresponding rehabilitation methods

수치해석을 통한 비포장도로 개선을 위한 공법별 적용 효과 연구

강경남,박해원,김용주 한국아스팔트학회 2022 한국아스팔트학회지 Vol.12 No.2

Many developing countries have many unpaved roads that should be applied the optimal methods for improving the unpaved roads within the limited budget. With three clay-based road conditions in southeast Asia countries, four improvement methods are applied on the top of the unpaved roads and then the behaviour of the surface and underlayer of the treated road under the traffic loading are compared by numerical analysis based on the Mohr-coulomb model. In this study, effect of several methods to improve the unpaved roads is analysed by comparing the behaviour results of a numerical analysis considering traffic loading on the improved unpaved road conditions. Based on the limited analysis results, it would be confirmed that some improvement methods can obtain positive effect on the several clay-based unpaved roads. However, it could be possible to determine effective improvement methods after running laboratory tests using the raw materials of unpaved roads.

아스팔트의 성능개선을 위한 고분자 재료의 특징과 현황

가현길 한국아스팔트학회 2023 한국아스팔트학회지 Vol.13 No.1

Domestic asphalt pavement is intensifying damage due to various reasons such as traffic volume and temperature changes. As a way to solve the damage of asphalt pavement, a modified asphalt mixture mixed with a modifier of asphalt is used. In particular, as an improvement measure to prevent plastic deformation among the types of damage to asphalt pavement, modified asphalt is used in which various modifiers are mixed into the asphalt. Asphalt modified materials mainly produce the effect of plastic deformation suppression by modifying the high temperature characteristics, which is asphalt vulnerability. In the case of modifiers used in Korea, there are various types of modifiers such as chemcrete, gilsonite, SBS, SBR, EVA, LDPE, etc. In this study, the types of asphalt modifiers were listed and the characteristics of each modifier were analyzed. In addition, the resistance to cracking and plastic deformation was comparatively analyzed through the indoor test results of hot mix asphalt and modified asphalt mixture.

국내 기후조건의 아스팔트포장에 대한 FWD 처짐값의 온도보정식 제안

최준성,오승훈,김상진,김장락,이종섭 한국아스팔트학회 2023 한국아스팔트학회지 Vol.13 No.1

To valuate the domestic asphalt pavement, it is necessary to consider the temperature of the four seasons with a large temperature change range. Therefore, the FWD deflection value tested at the temperature of each season must be corrected according to the reference temperature. In this study, a temperature correction formula of FWD deflections ware developed based on the long-term monitored section without performance change under domestic climatic conditions. As a result of applying the developed formula to FWD field data in the domestic temperature range, it was found that it can be appropriately used in Korea, where the mean value and standard deviation value has less fluctuation than the other existing temperature correction formula.

철도 아스팔트 콘크리트 궤도의 시공정밀도 및 주행 안정성 확보를 위한 실현장(중부내륙선 일부) 적용 사례 연구

나일호,정원우,박지용 한국아스팔트학회 2023 한국아스팔트학회지 Vol.13 No.1

Asphalt concrete tracks are excellent in terms of workability and economy, and have the advantage of improving running stability and easy maintenance. However, because it is constructed on site in the buttom-up method, methods for precise construction are required. The composition of the asphalt concrete track system can be divided into subgrade installation, asphalt concrete ballast installation, track installation, and vertical and horizontal resistance equipment, Management through guide wire and measurement is required to secure the precision of each process. If studies to increase precision are continuously promoted through these field installation studies, it will contribute to the technological development of asphalt concrete tracks.