인도네시아는 전 세계에서 여섯 번째로 많은 탄소 배출국으로, 2023년 기준 약 729 MtCO₂를 배출하며 아세안 국가 중 가장 높은 배출량을 기록하고 있다(Global Carbon Atlas). 이러한 탄소 배출은 주로 화석연료 사용과 산림 벌채로 인해 발생한다. 인도네시아 정부 는 파리기후협정에 따라 2030년까지 온실가스 배출을 29% 감축하는 목표를 설정했으며, 이를 달성하기 위해 다양한 저탄소 기술 도입 이 필수적이다. 특히, 도로 건설 분야에서는 탄소 저감과 시공 효율성을 동시에 향상시킬 수 있는 중온 아스팔트(Warm Mix Asphalt) 기술이 중요한 역할을 한다. 본 연구에서는 인도네시아에 적합한 중온 아스팔트 기술의 적용 가능성을 평가하기 위해, 국내 골재와 중온첨가제를 사용하여 인도 네시아 현지 바인더(IN 6070, 침입도 60-70)와 국내 아스팔트 바인더(PG64-22, 침입도 60-80)를 각각 비교 분석하였다. 인도네시아 시방 기준에 따라 배합설계를 수행하였으며, 합성입도는 인도네시아 시방기준과 유사한 입도(WC-2)를 적용하였다. 또한 현지 바인더와 국내 바인더를 비교하여 성능 차이를 분석하고, 중온첨가제를 사용한 경우와 그렇지 않은 경우의 혼합물 특성도 평가하였다. 아스팔트 바인더 시험 결과, 인도네시아 바인더는 국내 바인더와 유사하였으며, 중온첨가제를 적용한 경우 점도가 모두 낮아지는 경 향을 보였다. 혼합물 시험 결과(국내 골재 사용) 두 바인더 모두 유사한 성능을 나타냈으며, 중온첨가제를 사용한 경우 가열 아스팔트 대비 약 30℃ 낮은 온도에서도 공극률이 유사하였고, 품질 기준을 모두 만족하였다. 향후 인도네시아의 골재와 바인더에 국내 중온첨 가제를 적용한 시험 결과가 본 연구와 유사하게 나타난다면, 국내 중온첨가제를 인도네시아 도로 건설에 적용할 수 있을 것으로 판단 된다.

본 연구에서는 온도 반응형 발열 아스팔트 포장 공법 개발을 위하여 온도 반응형 신소재의 아스팔트 적용 방안과 이를 아스팔트 재 료에 적용하기 위한 기초 연구를 수행하였다. 발열 아스팔트 포장에 적합한 상변화 온도 범위에 따른 PCM 재료 선정 및 아스팔트 재 료에 적용하기 위한 캡슐화 방안을 검토하고 다양한 소재를 활용한 캡슐화된 PCM 신소재(ePCM)를 제작하였다. 이에 대한 발열 특성 및 물리적 특성 평가를 수행하였다.

2022년 기준 국내 폐타이어 발생량은 약 37만톤으로 그 중 88.9% 인 약 32만 9천톤이 재활용되는 것으로 조사되었다. 하지만 이 중 약 75%가 시멘트소성로용 등 열이용 분야에 사용되었다. 폐타이어는 대부분 고무와 플라스틱으로 이루어져 있기 때문에, 고온에서 분 해되면서 다양한 유해가스와 오염물질이 발생할 수 있고, 이러한 공해물질은 적극적으로 관리되지 않으면 대기오염, 수질 오염 등 다 양한 환경문제를 발생시킬 수 있다. 때문에 친환경적이고 지속적인 재활용에 대한 필요성이 대두되고 있다. 폐타이어 고무 분말을 아스팔트 혼합물의 골재 일부로 치환하여 재활용하는 접근 방식은 환경에 미치는 영향을 완화할 뿐만 아니라 천연 자원의 고갈 측면에서도 긍정적인 영향을 미치는 것으로 판단된다. 따라서 타이어분말을 아스팔트 혼합물에 적용하는 것은 환경 문제를 해결하고 자원 효율성을 높이는 두 가지 이점을 가지고 있다. 폐타이어 분말을 아스팔트 바인더와 아스팔트 혼합물에 적용할 경우 미치는 영향을 평가하기 위하여 TTI의 반사균열 저항성 시험, FN Test를 진행하였다.

PURPOSES : This study analyzed the amount of fuel consumption and atmospheric emissions by type of asphalt concrete mixtures. METHODS : Asphalt concrete mixture was produced directly at the plant, fuel consumption was measured compared to daily production, and atmospheric emissions emitted during the production process were measured. Hot and warm asphalt mixtures were produced, and analyses were conducted according to weather conditions and production volume. RESULTS : The fuel use per ton was confirmed to reduce energy by approximately 23.5% in WMA compared to HMA due to differences in the production temperature during the production of asphalt mixtures. Additionally, HMA production yielded 1.6 times higher atmospheric emissions for CO2 and 3.8 times higher for NOx than that for WMA, indicating that CO2 and NOx emissions tended to increase as fuel consumption increased. CONCLUSIONS : When producing asphalt mixtures, the production temperature, production volume, atmospheric conditions, and site conditions have a significant impact on fuel usage and atmospheric emissions.

택코트란 아스팔트 포장 공사 시 기존 아스팔트층과 신설 아스팔트 층 사이에 부착성을 증가시키기 위하여 사용되는 재료이다. 교통 하중으로 인해 포장 경계면에서 수평전단응력 및 수직인장응력이 발생하게 되는데 택코트의 유실, 양생 부족 등의 문제로 접착 성능 이 부족하면 포장층의 분리, 밀림과 같은 도로 파괴가 형상이 나타날 수 있다. 현재 국내에서는 국토교통부 아스팔트 콘크리트 포장 시공 지침에 택코트 살포량에 대한 기준은 존재하지만 기존 및 신설 아스팔트 포장층 사이에 택코트의 접착강도에 대한 기준은 존재 하지 않는 실정이다, 이는 접착강도 특성이 분석되지 않은 택코트를 사용함에 따라 아스팔트 포장의 공용성 측면에서 문제를 초래할 수 있다. 따라서 본 연구에서는 PG등급이 다른 택코트 4종류에 대한 인장 및 전단접착강도를 확인하기 위하여 인장접착강도 시험, 전 단접착강도 시험을 진행하였다. 택코트의 양생정도에 따른 접착강도 특성을 확인해보기 위하여 택코트의 수분이 증발됨에 따라 중량 변화가 없는 상태를 양생 100%로 하여 양생 0%, 50%, 100%로 진행하였으며, 살포량은 국토교통부 아스팔트 콘크리트 시공 지침에 따 라 0.5ℓ/m2로 진행하였다. 사용된 택코트 종류에 관계 없이 양생 정도가 증가함에 따라 접착강도는 증가하는 추세를 보였으며, 인장 및 전단접착강도 시험에 관계없이 초기 양생(양생 0%~50%)보다 양생 50% 이후에서의 더 높게 강도가 발현된 것을 확인하였다. 또한 PG등급이 높은 택코트가 인장 및 전단접착강도에 관계없이 접착강도 성능이 우수한 것을 확인할 수 있었다. 추후 택코트의 종류를 추 가하여 PG등급이 분류가 이루어진 후에 접착강도 시험을 진행하여 결과를 확인할 예정이다.

PURPOSES : In this study, energy-consuming processes in asphalt plants were evaluated, and the drying and mixing processes were characterized using a thermal equilibrium equation-based model to quantitatively estimate the amount of energy consumed during the production of mixtures in asphalt concrete plants. METHODS : An energy consumption model based on the thermal equilibrium equation was used to estimate the energy consumption of the aggregate drying process that consumes the maximum energy; the energy consumed for material transportation, storage, and operation of other facilities was cited from the literature. The results were compared with the actual results obtained for recycled hot asphalt mixtures and recycled warm mix asphalt mixtures, and a sensitivity analysis was performed by varying the conditions. RESULTS : An analysis of the main processes required to produce asphalt mixtures showed that the water content had the largest impact on energy consumption (approximately 80%). This quantitatively supports the opinion of field practitioners that maximum energy is consumed during aggregate drying. Although some discrepancies were observed, the results were found to be reasonable and within the range of typical measurements. CONCLUSIONS : The thermal energy consumption estimation model provides consistent results that reflect the characteristics of the mixture and can be used to derive the thermal energy consumption rates for individual materials, such as aggregates and binders. This can be used to identify the priorities for process optimization within a plant.

PURPOSES : This study was conducted to compare and evaluate the compaction performance and physical properties of recycled asphalt mixtures by utilizing the characteristics of hot-mix asphalt mixtures and foamed asphalt. METHODS : A wearing-course mixture was used for performance evaluations. Subsequently, dynamic shear rheometry (DSR), compaction performance, general physical properties, tensile strength ratio, and Hamburg wheel tracking were tested. RESULTS : As a result of performance comparisons, compaction, and general physical properties satisfied the quality standards. In the Hamburg wheel tracking test, the mixture with the antistripping agent improved performance by approximately 40% compared with the general mixture. As the foamed asphalt binder was produced at a relatively low temperature compared with the general hot-mix asphalt binder, the penetration, viscosity, and DSR test results of the aged foamed asphalt binder showed that the aging of the asphalt binder was suppressed, and the flexibility increased. Therefore, the resistance to fatigue cracks is expected to be enhanced. CONCLUSIONS : Even though the foamed warm-mix recycled asphalt mixture was produced at a temperature that was 20~30°C lower than the hot-mix asphalt mixture, its physical properties were similar to those of the hot-mix asphalt mixture; its use is expected to reduce the production of fuel and air pollutants.

PURPOSES : This study compared the performance evaluation of a hot mix asphalt (HMA) and asphalt mixture of a warm-antistrip agent. METHODS : A mix design applying Korean standards was conducted to evaluate the performance evaluation. Thereafter, the quality standard evaluation of the asphalt mixture produced was conducted, and if all quality standards were satisfied, a performance evaluation was conducted. Types of performance evaluation included the Hamburg wheel tracking test and dynamic modulus test. RESULTS : As a result of the Hamburg wheel tracking test, the asphalt mixture with a warm-antistrip agent obtained a lower sedimentation value at 10000 times and 20000 times. This result is considered to have higher plastic deformation resistance of the asphalt mixture with a Warm-antistrip agent than HMA. The U.S. Department of Transportation stipulates that plastic deformation resistance is excellent if the asphalt mixture does not exceed 20,000 times the precipitate of 20 mm. Therefore, we confirmed that the plastic deformation resistance of the asphalt mixture with a warm-antistrip agent was excellent. Additionally, the master curve was analyzed by synthesizing the results of the dynamic modulus test. When analyzing the low load cycle at the bottom left of the master curve, the dynamic modulus value of the master curve was higher in the asphalt mixture with a warm-antistrip agent than in the HMA. In addition, when analyzing the high load cycle part, the dynamic modulus of the HMA was measured to be higher than that of the asphalt mixture with a warm-antistrip agent. Accordingly, the resistance to fatigue cracking of the asphalt mixture with a warm-antistrip agent was considered superior to that of the HMA. CONCLUSIONS : As a result, we confirmed that the asphalt mixture with a warm-antistrip agent that satisfies the Korean quality standards had better plastic deformation and fatigue resistance for all performance evaluation tests conducted in this study than the HMA. However, since the Hamburg wheel tracking test did not significantly differ in the amount of sedimentation in the performance evaluation tests and the mixture using one additive was compared with HMA, studies on the effects of various additives containing warm-antistrip agents are required.

PURPOSES : Graphene nanoplates, which have recently been in the spotlight in various fields, are a layer of graphite used in pencil leads, with carbon arranged in hexagonal honeycomb shapes. The graphene is 0.2 nanometers thick, and it possesses high physical and chemical stability, high strength, and conductivity. These graphene nanoplates have been studied for application in various devices such as semiconductors and batteries, and in the construction sector, where they are used as additives to improve the durability of cement concrete. The purpose of this study was to investigate the physical, and functional properties of graphene-modified asphalt mixtures. METHODS : In this study, the graphene input content of asphalt mixture samples was determined using an asphalt performance grade (PG) test. Based on the results of the test, their strength, stiffness, thermal properties, and electrical conductivity were evaluated. Indirect tensile strength test and dynamic modulus (DM) test were conducted to evaluate the strength and stiffness, and thermal conductivity tests and electrical conductivity evaluations were conducted for determining the functionality of the graphene-modified asphalt mixtures. The thermal conduction test was used to measure the external temperature change over time by placing a general heated asphalt mixture and graphene-modified asphalt with the same raw material-specific mixing ratio inside the temperature chamber in order to measure the heat conductivity. The electrical conductivity was evaluated using a digital multimeter to measure the resistance of DC voltage and DC current via a 4-probe method. RESULTS : The performance grade (PG) test results showed that, for a dynamic shear rheometer (DSR), both tests met the baseline and that physical changes in the binder did not appear evident with graphene addition. Furthermore, each content met the baseline for the bending beam rheometer (BBR). The increasing ratio of flexural creep stiffness approached the maximum when 7.5% graphene was used. In indirect tensile strength test, an average of thrice the indirect tensile strength for graphene-modified asphalt was 0.92 N/mm2, which was approximately 0.04 N/mm2 higher than the average measured three times that of hot mix asphalt mixture, with the same raw material mixing ratio. In the thermal conduction tests, the temperature and the rate of change of temperature of the graphene-modified asphalt mixture were higher than those of the hot-mix asphalt mixture. Lastly, the results of the electric conductivity test using the 4-probe method showed that the electrical conductivity increased slightly as the graphene content increased, but overall, it showed very low electrical conductivity. CONCLUSIONS : In this study, the potential for enhancing the physical and functional performance of graphene nanoplates applied to asphalt mixtures was demonstrated. However, it is practically difficult to arrange graphene particles continuously within an asphalt mixture, which is believed to have very low electrical conductivity.

PURPOSES : The purpose of this study was to evaluate the newly developed Guss mastic asphalt mixtures, called EQ-mastic asphalt mixtures, which contain melted additives for decreasing cooking time. METHODS : A series of experiments were performed to investigate the effectiveness of the melted additives in EQ-mastic asphalt mixtures. Both the existing Guss mastic asphalt mixture and the EQ-mastic asphalt mixture were produced with the same amounts of asphalt binders, aggregates, and fillers, but the existing Guss mastic asphalt mixture contained 3% Trinidad lake asphalt (TLA). The EQ-mastic asphalt mixture contained 3% of additives, including TLA and polyolefin. The physical material performances of both mastic asphalt mixtures were obtained by conducting the Luer fluidity test, penetration test, dynamic stability test, and low-temperature bending test. The results of the tests for the existing Guss mastic and EQ-mastic asphalt mixtures were compared. RESULTS : The fluidity, penetration, dynamic stability, and low-temperature bending strains of both the existing Guss mastic and EQmastic asphalt mixtures all satisfied the standard values provided in the production and construction guides of the Guss mastic asphalt pavement. CONCLUSIONS : When melted additives containing polyolefin are used in the production of Guss mastic asphalt mixtures, the cooking time decreases, so that the corresponding energy consumption and asphalt fume amount can be reduced. Therefore, an EQ-mastic asphalt mixture is proposed for use as an eco-friendly pavement material.

PURPOSES : The purpose of this study is to analyze the effect of ions in emulsion asphalt on recycling cold asphalt concrete and suggest the possibility of using anionic and nonionic emulsion asphalt. METHODS : In this study, indirect tensile strength, toughness, tensile strength ratio, and dynamic immersion tests were conducted to determine the effects of cation, anion, and non-ion emulsified asphalt on the cold recycled asphalt mixture. Crack resistance was evaluated through indirect tensile strength and toughness tests and the tensile strength ratio and dynamic immersion test were evaluated through tensile strength ratio and dynamic water immersion test. RESULTS : Indirect tensile strength and toughness measurement results demonstrated that the mixture using anion and non-ion emulsified asphalt tended to be higher than that using cation emulsified asphalt; this is due to the high content of reclaimed asphalt pavement with a cationic or ionic surface, which is related to the use of cation-emulsified asphalt in the mixture and has shown a low strength tendency. The tensile strength ratio measurement demonstrated that the mixture using non-ion emulsified asphalt tended to be approximately 15 % higher than that of the anion mixture. This demonstrated that the chemical additive used in the mixture showed a complete hydration reaction with the distribution to the mixture. The dynamic immersion test indicates that the aggregate film rate of asphalt is highly influenced by the surface electric charge of the new aggregate while the ionicity effect appears to be insignificant, at 75 - 85 %, when circular aggregates are used. CONCLUSIONS : High reclaimed asphalt pavement content in cold recycled asphalt mixture, as well as non-ion and anionic emulsified asphalt, is advantageous, reducing cracking and improving moisture resistance. It is believed that anions and non-ions may be better utilized than applying the existing criteria to the cold temperature recycled asphalt mixture with high reclaimed asphalt pavement content. In addition, if the scope of the emulsified asphalt is expanded, various additives can be used, which will require analysis of materials, such as fertilizers and additives.

PURPOSES : The objective of this study is to address various problems, such as an increase in material cost and premature failure (e.g., cracks and potholes) of porous pavements, and to develop multifunctional asphalt and asphalt mixtures to ensure the long-term commonality of porous asphalt pavements. METHODS : A basic quality test of two types of porous asphalt mixtures was performed. One type consisted of the existing porous asphalt mixture, using domestically presented grading, and the other a porous asphalt mixture using high-viscosity modified asphalt with enhanced low-temperature properties, aimed at improving strain resistance and developed by applying the grading suggested by the Federal Highway Administration (FHWA). RESULTS : The cantabros loss rate was 19.62 % for conventional modified asphalt (PG 82-22) and 5.95 % for the developed highviscosity modified asphalt (PG 88-28), indicating that both mixtures passed the criteria. Regarding the drain-down loss rate, mixtures using both types of asphalt were found to pass all quality standards. The average permeability coefficients for each porous asphalt mixture were 0.023 and 0.018 and both types of porous asphalt mixtures satisfied the quality standard of 0.01 cm/s, as given by the Asphalt Concrete Pavement Guidelines of the Ministry of Land, Infrastructure, and Transport. CONCLUSIONS : As a result of the mix design of the two porous asphalt mixtures, the mixture developed in this study was found to be superior to the conventional porous asphalt mixture using conventional porous asphalt grading and modified asphalt.

PURPOSES : This study was performed to evaluate the short-term aging (SA) protocols of the normal hot-mix asphalt (HMA) mixture, to explore problems, and to suggest proper procedures based on fundamental principles of SA in terms of the SA temperature (T) and length of time (Lt) in existing specifications in several countries including Korea. METHODS : As the SA in our lab is a simulation of field SA, which is an inevitable procedure occurring naturally in the current field practice, major SA guidelines of foreign countries and Korea were reviewed to investigate problems that showed discrepancies with field practice. The aging quantity (Aq) model was introduced as a function of T and Lt, based on the correlation with absolute viscosity (AV) to estimate Aq by T and Lt. The normal SA (NSA) was suggested through an example procedure inducing binder aging level similar to the RTFOtreated binder AV or Aq. Based on the NSA Aq level, lower, proper, or higher SA conditions were discovered from the existing SA guidelines. RESULTS : As Aq has excellent correlation with AV, the proper T and Lt for NSA as an example was suggested based on the AV of RTFOtreated binder to induce an Aq range of 19,000-25,000 min.℃. It was found that there were several problems in the existing guidelines in USA and Korea. These included lower T, shorter or longer Lt, and air blowing or stirring the mix during SA, which were not matched with the practical condition of loaded HMA mixtures that were short-term aged under hot temperatures in trucks. CONCLUSIONS : It was concluded that there are several problems in the current SA guidelines, which do not provide proper HMA temperature to mixtures for proper (modal) length of time. Therefore, these guidelines should be reevaluated carefully and revised based on the fundamental field SA principle. The NSA condition should be suggested using proper HMA T and modal Lt for better simulation of field SA practice.

PURPOSES: The objective of this study is to evaluate the physical properties of recycled asphalt mixtures reinforced with glass fiber. METHODS: Firstly, mixing design was conducted on recycled asphalt mixture for use of 50% recycled aggregate. Various laboratory tests were performed on four types of recycled asphalt mixtures with different glass fiber content to evaluate the physical properties. The laboratory tests include indirect tensile strength test, dynamic modulus test, Hamburg wheel tracking test and tensile-strength ratio to evaluate cracks, rutting and moisture resistance of mixtures. RESULTS: The indirect tensile strength of fiber reinforced glass increased about 139.4%. As a result of comparing the master curves obtained by the dynamic modulus test, the elasticity was low in the low temperature region and high in the high temperature region when the glass fiber was reinforced. The glass fiber contents of PEGS 0.3%, Micro PPGF 0.1% and Macro PPGF 0.3% showed the highest moisture resistance and rutting resistance. CONCLUSIONS : The test results show that use of glass fiber reinforcement can increase the resistance to cracking, rutting, and moisture damage of asphalt mixtures. It is also necessary to validate the long-term performance of recycled asphalt mixtures with glass fiber using full scale pavement testing and field trial construction.