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.

매립부지의 시설위치 선정을 위한 지진시 지반재해 영향평가 사례연구

최재순,백우현,김장태 한국아스팔트학회 2023 한국아스팔트학회지 Vol.13 No.2

Since 1980s, due to the rise in domestic real estate prices, it has become difficult to secure land for the construction of social overhead capital. Instead, the necessary land has been secured through reclamation of domestic coastal areas, and such attempts have continued in recent years. Meanwhile, due to the 1995 southern Hyogoken-Nambu earthquake that struck Kobe, most of Kobe Port, built on reclaimed land, lost its port logistics distribution function due to soil liquefaction. The Korean peninsula, previously considered a safe zone against earthquake, experienced soil liquefaction in 2017. In this study, a method for evaluating the impact of ground disasters during earthquakes was presented in selecting the locations of roads and major facilities when making construction plans on reclaimed lands, and the assessment for seismic geotechnical disaster was performed in actual reclaimed lands

Sphalt 배수성 아스팔트 바인더 특성 분석

장영두,이재식,김동균 한국아스팔트학회 2023 한국아스팔트학회지 Vol.13 No.2

Drain asphalt pavement has many advantages such as drain function and noise function, but it is not widely used in Korea due to loss of drain function during use and poor durability such as desorption of aggregates. However, if a binder suitable for the characteristics of drain asphalt is developed and applied, it is expected to be used continuously in the henceforward. Therefore, in this technology, the characteristics of the high-viscosity Sphalt drain binder developed to solve the problem are described. Spalt drain binder is a binder developed to produce a homogeneous mixture because it has excellent storage stability and reduces phase separation during transportation and storage.

Laboratory investigation on storage stability based on physical properties and microstructural image depending on rubber particle size for CRM asphalt binder

Jihyeon Yun,Sushmit Sharma Bhattarai,Hyunhwan Kim,나일호 한국아스팔트학회 2023 한국아스팔트학회지 Vol.13 No.2

In this research, the viscoelastic properties and microstructure of asphalt binders modified with two Crumb rubber modifiers (CRM), #50 and #30, using mechanical tests and Atomic force microscopy (AFM) were evaluated. Each modified asphalt binder was prepared by mixing 5% and 15% CRM. The Separation index (SI) of each binder was calculated using rheological measurements (G*/sin δ and % recovery). Additionally, AFM was employed to capture topographical images of the CRM asphalt binders, aiding in a comprehensive assessment for SI. The key findings include (1) enhanced rheological properties in the lower sections of CRM asphalt binders, attributed to density differences between the CRM and the base asphalt; (2) lower SI in #50 CRM binders, correlating with their more uniform particle distribution; and (3) microstructural distinctions observed via AFM, with #50 CRM binders showing uniformity across top and bottom layers, unlike #30 CRM binders. These insights demonstrate that microstructural images can be an effective tool for assessing the storage stability of CRM asphalt binders, thereby contributing significantly to a more in-depth understanding of their stability.

불투수 차단층(샌드 매스틱) 혼합물의 현장 적용성 평가

조문진,신현국 한국아스팔트학회 2023 한국아스팔트학회지 Vol.13 No.2

In Korea, concrete pavements account for 66% of all pavements and Jointed Concrete Pavement (JCP) is the main one. Spalling of joints, which is a representative damage of JCP pavement, is threatening ride comfort, vehicle damage, and driver safety. There is an increasing interest in maintenance methods due to aging of concrete pavement. As a repair method for aged concrete pavement, the asphalt overlay method, which is advantageous in smoothness, noise, and construction period, is most often applied. However, pavement damages such as reflection cracking, shoving and pothole occur due to lack of adhesion between the existing concrete pavement and the new asphalt pavement. There is a need for a new method for preventing such pavement damage and extending the life of the pavement. In this investigation, an impermeable layer was applied on top of the existing JCP to reduce reflection cracking propagating from the bottom, increase adhesion with the existing pavement, and prevent penetration of rainwater and chlorides from the top. Thus, the durability of the pavement was secured and the lifetime of the pavement was extended at the same time. The impermeable layer is a thin sand mastic mixture(TSM) using a binder of PG88-34 with improved performance at low and high temperatures. In this study, the reflection cracking resistance, rutting resistance, and low-temperature bending strain of the TSM were evaluated through lab experiments, and field applicability was confirmed through test beds.

통계분석 기법을 적용한 고점도 아스팔트 바인더의 저온 휨 특성 연구

박건호,박성현,박태순,문기훈 한국아스팔트학회 2023 한국아스팔트학회지 Vol.13 No.2

Porus asphalt pavement, with a 20% porosity compared to conventional asphalt, allows for the generation of high-pressure water infiltration during rainfall. To prevent premature oxidation of the asphalt binder due to exposure to UV rays and wind, high-modulus asphalt binders are utilized. In addition to the standard performance grade test, a flexural beam test is conducted for freeze-thaw vulnerability assessment. Currently, flexural beam test is conducted at -20°C regardless of the performance grade. To evaluate the suitability of this test temperature, mathematical modeling and statistical analysis were performed, confirming the appropriateness of the current flexural beam test temperature of -20°C.

시그모이드함수 기반으로 아스팔트 바인더의 극한영역 모델링 연구

조상갑,박태순,문기훈 한국아스팔트학회 2023 한국아스팔트학회지 Vol.13 No.2

This study was performed to predict the viscoelastic behavior on Asphalt binder by means of mathematic modeling approach. As testing material, PG 64-22 asphalt binder was prepared. The Dynamic Shear Rheometer (DSR) test was performed as mechanical experimental activities of asphalt binder. As result, complex shear modulus of given asphalt binder at various temperature and frequency conditions was computed then generated. To predict and analyze the global mechanical performance of tested asphalt binder from DSR test results, a master curve construction and generation approach was considered. In the previous studies, two mathematical models: Sigmoidal and Richards models, were considered to predict the global complex shear modulus pattern of given asphalt binders. However, not many studies considered on developing more advanced mathematical models on global complex shear modulus behavior than the previous ones in the past decades. In this paper, three different mathematical modeling approaches for complex shear modulus master curve construction were introduced. It was found that the newly developed three mathematical models can successfully explain and predict global complex shear modulus of asphalt binder compared to the previous ones. This means there can be more options for DSR test results prediction. More experimental works and corresponding analyses are needed to further strengthen the findings in this paper as a future research.

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.

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.