PURPOSES : The purpose of this paper is to evaluate the performance of MAST composite pavement. METHODS : A Testbed with three different sections with varying pavement materials were constructed: Section 1 (MAST(Multi-Layered Asphalt Surface Treatment) Composite Pavement; RCC(Roller Compacted Concrete)+Modified DBST(Double Bituminous Surface Treatment), Section 2 (Aggregate base+Modified DBST), and Section 3 (aggregate base+General DBST). The structural stability and skid resistance were evaluated using LFWD test and sand patch test, respectively. Moreover, laboratory specimens of four different pavement materials (HMA(Hot Mix Asphalt), Gravel base+DBST, RCC+DBST, and RCC+Modified DBST) were fabricated using and the rutting resistance of each pavement type was evaluated using the MMLS3. RESULTS : As a result of the LFWD(Light Falling Weight Deflectometer) test, the elastic modulus of Section 1 was significantly higher compared to the other section with values between 450 MPa to 650 MPa. Meanwhile, the elastic modulus of Section 2 and Section 3 were almost similar from 50 MPa to 150 MPa. Moreover, sand patch test results showed that Section 1 and Section 2 have an excellent surface roughness with values higher than 0.7 mm but Section 3 has a poor surface roughness with MTD(Mean Texture Depth) value of 0.4 mm. Lastly, based on the results of the MMLS3(third scale Model Mobile Load Simulator) test, gravel base+DBST showed the lowest resistance to rutting among the four specimens, and both RCC+modified DBST and RCC+DBST showed good performance up to 600 loading cycles, but the rut depth increased rapidly until 1,000 loading cycles. CONCLUSIONS : MAST composite pavement(RCC+modified DBST) has superior structural stability compared to general DBST pavement (aggregate base+DBST), has excellent skid resistance with values higher than 0.7 mm, and has similar rutting resistance to that of general dense asphalt concrete pavement. Therefore, exhibiting its good performance in both structural and functional aspects, it can be concluded that MAST composite pavement(RCC+modified DBST) can be an effective alternative for pavement material in Southeast Asian developing countries where support for heavy vehicle loads is required and rutting is likely to occur.

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 intended to derive a methodology that can evaluate water splash caused by distress on the road surface based on experimental methods and to present quantitatively by analyzing the impact on road users. METHODS : Through literature review, the current problems of road pavement and drainage facility standards, the factors of road splash caused by puddle was selected to measure damage. Field measurements were conducted by setting different conditions for each factors and setting different conditions based on the hypothesis. In addition, water splash by surface distress type and puddle was measured to analyze using statistical techniques from correlation to multi-regression. RESULTS : The maximum and effective distance due to road splash increases as the driving speed, regardless of vehicle load and tyre type. Splash was measured according to the type of road distress to analyze the correlation between the influencing factors, and there was a weak correlation between the width and length of the puddle, depth and the effective distance. In addition, the interaction analysis showed that there was an interaction between the width of the water hole and the depth of puddle. Moreover, based on the multi-regression analysis, it was not statistical significant. This is judged to that the number of data samples used for this analysis is limited because the diversity of puddle conditions cannot be set differently for each type of distress. CONCLUSIONS : Since the distress of depending on the size, depth and shape of the road surface, it is necessary to calculate it and present maintenance standards, so this results present an experimental methodology that can intuitively evaluate damage cased by unestablished puddle. From this results, this is expected to be used as a quantitative indicator to evaluate the satisfaction of road users as a functional performance according to road surface condition.

PURPOSES : The objective of this study is to develop the data driven pavement condition index by considering the traffic and climatic characteristics in Incheon city. METHODS : The Incheon pavement condition index (IPCI) was proposed using the weighted sum concept with standardization and coefficient of variation for measured pavement performance data, such as crack rate, rut depth, and International Roughness Index (IRI). A correlation study between the National Highway Pavement Condition Index (NHPCI) and Seoul Pavement Condition Index (SPI) was conducted to validate the accuracy of the IPCI. RESULTS : The equation for determining the IPCI was developed using standardization and the coefficient of variation for the crack rate, rut depth, and IRI collected in the field. It was found from the statistical analysis that the weight factors of the IPCI for the crack rate were twice as high as those for the rut depth and IRI. It was also observed that IPCI had a close correlation with the NHPCI and SPI, albeit with some degree of scattering. This correlation study between the NHPCI and SPI indicates that the existing pavement condition index does not consider the asymmetry of the original measured data. CONCLUSIONS : The proposed pavement condition provides an index value that considers the characteristics of the original raw data measured in the field. The developed pavement condition index is extensively used to determine the timing and method of pavement repair, and to establish pavement maintenance and rehabilitation strategies in Incheon.

PURPOSES : Fine dust significantly affects the atmospheric environment, and various measures have been implement to reduce it. The aim of this study is to reduce fine dust on roads by implementing porous pavements and a clean road system using the low-impact development technique. METHODS : We conducted quality tests (draindown, cantabro loss rate, tensile strength ratio, dynamic stability, and indoor permeability coefficient tests) and performance evaluation (dynamic modulus and Hamburg wheel-tracking tests) on the porous asphalt mixture. Subsequently, we constructed a porous pavement road in a test bed and conducted a permeability test. In the test bed, we installed a nozzle, a water tank, and a fluid pump to water the roadside. After the clean road system was completely installed, we measured the concentration of fine dust before and after water was sprayed. Additionally, we conducted a total suspended solids (TSS) test to confirm the reduction in re-suspended dust. RESULTS : All results from the quality test of the porous asphalt mixture satisfy the standards stipulated by the Ministry of Land, Infrastructure and Transport. Results from the dynamic modulus test show a low plastic deformation resistance but a high fatigue crack resistance. The results from the Hamburg wheel-tracking test satisfy the U.S. Department of Transportation standards. After the porous pavement was constructed, a permeability test was conducted, and the result satisfies the standard value. Using a particle counter, we measured the concentration of fine dust before and after water spraying, and results show 12.08% and 10.23% for PM10 and PM2.5 particles, respectively. The results from the TSS test show that after the initial water spray, almost all re-suspended dust are removed from a road. In unfavorable road conditions, almost all re-suspended dust are removed after a second water spray. CONCLUSIONS : The results of all of quality tests performed on a porous asphalt mixture satisfy the standards. By applying the results to a test bed, the problem of securing water is solved. Using the clean road system, 12.08% and 10.23% of PM10 and PM2.5 particles are removed, respectively. The system removes PM10 particles (larger particles) more effectively compared with PM2.5 particles. IN the future, we plan to revise the maintenance plan such that the porous pavement can exhibit long-term performance. Because pipe freezing may occur in the winter, we plan to analyze the periodic maintenance plan of the porous pavement and develop a solution to mitigate the issue of freezing pipes in the winter.