Research on the Impact of Recycled Asphalt Mixture on Road Performance Based on New Thermal Recycling

Different binder content to RAP Regeneration SBS modified asphalt mixture for road performance to SBS modified asphalt (I-D type) as an index, determine the optimum dose of new heat regenerating agent and different RAP regeneration, and prepared different recycled asphalt, which have differences in RAP content. The performance of recycled asphalt mixture with different RAP content was evaluated by freeze-thaw splitting test. Rut test and Low temperature trabecular bending test. The correlation between RAP content and pavement performance was analyzed by grey system correlation analysis method. According to the experimental verification results, it can be known that increasing the content of RAP material can improve the high-temperature performance of reclaimed asphalt, but will result in a qualitative decrease in low-temperature performance and water temperature, but the above-mentioned performance can reach the required level, Shows that new heat regenerators play a role in the road performance of RAP materials, and for the RAP material utilization ratio of more than 50%, as for the gray correlation analysis, it can be found that there is a close correlation between the low-temperature performance of recycled asphalt mixture and the content of RAP material. The low temperature cracking resistance of asphalt mixtures will change significantly due to the slight changes in RAP materials.

Investigation of the Road Performance of AH-30 Bitumen and Its Mixture: Comparison with AH-70 and SBS-Modified Bitumen

AH-30 is a type of high-viscosity matrix asphalt. The asphalt mixture made by AH-30 as a binder has an excellent antirutting performance. However, the other road performance of AH-30 was still worthy of attention. This research aims to reveal the properties of AH-30 and its impact on the road performance of asphalt mixtures (AH30-AC20/25). The AH-70 neat asphalt and SBS modified asphalt were prepared for comparison. The high-temperature sensitivity and fatigue resistance of AH-30 are evaluated by the dynamic shear rheological (DSR) test. The low-temperature performance is evaluated by the bending beam rheometer (BBR) test. The high-temperature stability (HTS) of AH30-AC20/25 is carried out by the wheel tracking (WT) test and the repeated shear constant height (RSCH) test. The low-temperature crack resistance (LTCR) is carried out by the direct stretching (DS) test. The fatigue property is carried out by the three-point bending test. Water stability (WS) is carried out by the Marshall residual stability (MRS) and the intensity ratio of the frozen and melted (IRFM) test. The test results show that the high-temperature resistance of AH-30 is better than that of AH-70. The low-temperature crack resistance of AH-30 is equivalent to that of AH-70. The AH-30 as a binder can meet the requirements of the roads, which are located at a minimum temperature of not less than −10.5°C in winter. The fatigue property of the AH-30 asphalt mixture is poor, which may be one reason why AH-30 asphalt pavement is more prone to cracking. The water stability of the AH30-AC (20/25) asphalt mixture can meet the specification requirements, and AH30-AC20 is better than the other two asphalt mixtures. The research of this paper will provide a basis and reference for the popularization and application of AH-30 in asphalt pavement.

Analisis Pengaruh On-Street Parking terhadap Kinerja Jalan di Pasar Jaya Ciracas, Jakarta Timur

This research contains an analysis of the traffic performance by dint of on-street parking, afterward the results are compared with the traffic performance if a scenario is made that there is no on-street parking activity. The purposes of this research are to determine the impact of on-street parking to road performance also to perceive the road level of service. The method used in this research is a quantitive method by direct field research. The results of this research are on-street parking activity around Jaya Ciracas Market affected the traffic performance with a difference in road capacity about 39,03%. The value of the road level of service when there is on-street parking activity is D, while when on-street parking is abolished, the road level of service can increase to C.

Optimizing The Functional Performance of Road Network using Vulnerability Assessment to Cope with Unforeseen Road Incidents

An Urban Road network is often used for multipurpose trips, due to their transportation functions, such as attractiveness and orientation, as well as social, ecological, and economic features. In Indonesia, road incidents have reportedly increased during the last decade because of a higher frequency of natural hazards, accidents, and on-street mass demonstrations. These incidents are found to degrade or terminate road access, forcing users to utilize alternative routes and decreasing the service performance in adjacent directions. Due to the unexpected occurrences at any location and time, there is a need to investigate the impact of random incidents on road performances. Several accessibility indexes have also been used to evaluate the vulnerability of road networks. However, this is less practical in Indonesia, with the road authority using functional performances as the indicator. This indicates the need for an index to be developed based on road performance parameters. Therefore, this study aims to develop a road performance-based vulnerability index known as the RCI (Road Criticality Index). Combined with a traffic simulation tool, this system is used as an alternative index to assess vulnerabilities, by identifying the road(s) providing worse consequences due to unforeseen incidents. This simulation was conducted by using the PTV Visum, assuming a road section is closed due to the worst incident scenarios. The result showed that the RCI offered a more comprehensive assessment than the existing indicator (volume capacity ratio). The RCI included travel speed and mobility components for evaluating both local and global road performances. With the knowledge of the most vulnerable locations and their consequences, road authorities can prioritize maintenance and development strategies based on the criticality index. Also, preventive measures should be conducted to mitigate risk under a constrained budget. This methodology can be applied to sustainably enhance the resilience of urban road networks.

Analisa Penyebab Kemacetan Dan Kecelakaan Jalan Raya Ngaliyan Kota Semarang Tanjakan Silayur

A traffic accident is a tragedy or accident that occurs on the road involving a motorized or heavy vehicle with other road users or without a vehicle. This incident caused the victim to suffer physical, health and material losses. Traffic accidents occur due to several factors such as human error or inadequate road conditions. Even traffic jams can also lead to traffic accidents. The problem of driving and road safety needs to be considered to reduce the number of traffic accidents that occur. This study was conducted to determine the factors that cause accidents, especially those caused by road conditions and traffic performance. The method used in the field observation research and using data on the number of accidents in 2018–2020 located on Jalan Raya Ngaliyan which was taken from the accident data of the West Semarang Police Traffic Unit. The level of road performance on Jalan Tanjakan Silayur Semarang City, at peak hours in the morning and non-peak hours during the day category C and at peak hours in the afternoon category E. Damage to the flexible pavement surface on Jalan Tanjakan Silayur is dominated by the type of damage cracks, grooves, and bleeding. One of the factors that caused the accident was because the traffic signs were not optimal on the Jalan Tanjakan Silayur section.

Design of Cold-Mixed High-Toughness Ultra-Thin Asphalt Layer towards Sustainable Pavement Construction

Ultra-thin asphalt overlay has become the mainstream measure of road preventive maintenance due to its good economic benefits and road performance. However, hot mix asphalt concrete technology is widely used at present, which is not the most ideal way to promote energy saving and emission reduction in the field of road maintenance. At the same time, the ultra-thin friction course based on cold mix technology, such as slurry seal layer, micro-surface, and other technologies, are still far behind the hot mix friction course in terms of crack resistance. In this research, by establishing an integrated design of materials and structures, a cold paving technology called “high-toughness cold-mixed ultra-thin pavement (HCUP)” is proposed. The high-viscosity emulsified bitumen prepared by using high-viscosity and high-elasticity modified bitumen is used as the binder and sticky layer of HCUP. The thickness of HCUP is 0.8–2.0 cm, the typical thickness is 1.2 cm, and the nominal maximum size of the coarse aggregate is 8 mm. Indoor tests show that HCUP-8 has water stability, anti-skid performance, high temperature performance, peeling resistance, and crack resistance that are not weaker than traditional hot-mixed ultra-thin wear layers such as AC-10, Novachip, and GT-8. At the same time, the test road paving further proved that HCUP-8 has excellent road performance with a view to providing new ideas for low-carbon and environmentally friendly road materials.

Comparing Young and Old Adults’ Night Hazard Detection With Driving Simulation and on Road

While there is validity of using driving simulation as a proxy for on-road performance, few studies have examined hazard detection at night. Night driving is a self-restricting practice with little evidence demonstrating the need with healthy older adults. This study’s objective was to analyze night driving using eye-tracking technology examining differences between on-road/simulated drives and older/younger adults. A 2 (old, young) x 2 (simulator, on-road) repeated-measures design measured three roadway “hazards” of pedestrains looking at their cell phone while posed to cross the roadway. Pupil glances were recorded using outcome measures of total fixation duration, number of fixations, and time-to-first fixation for the pedestrains on-road and on a specifically designed scenario matching the on-road route. Thirty-three healthy, community-living drivers age 65+ years (N=16) and drivers age 20-40 years (N=17) completed both drives. Using non-parametric statistics, results demonstrated that night hazard detection was similar across driving conditions except for time-to-first fixation, which was faster on-road for both age groups (p<.001). At some hazard locations, there were significant differences between the two age groups, with older adults taking longer to initially see hazards. Results suggest, older adults detected hazards similarly to younger adults, especially during on-road performance, suggesting avoidance of night driving may not be necessary. Results also support using driving simulation as a proxy for on-road with night driving needing to be incorporated. Additionally, eye-tracking has the potential for research in hazard detection with emphasis on the time-to-first fixation outcomes when considering driving analysis.

Road performance analysis of cement stabilized coal gangue mixture

In order to solve the environmental pollution of coal gangue and the shortage of aggregate resources in road engineering, waste coal gangue is used as road base material instead of natural stone materials. Through physical, mechanical, chemical and activity tests of coal gangue aggregate, the optimal gradation composition of unconfined compressive strength was determined. Through unconfined compressive strength, indirect tensile strength, flexural tensile strength, freeze-thaw and dry shrinkage tests, the influence of cement content on road performance of cement stabilized coal gangue mixture was studied. By means of SEM, ICP AES, XRD and optical digital microscope, the difference between spontaneous combustion coal gangue and Unspontaneous combustion coal gangue was analyzed, the microstructure of cement stabilized coal gangue mixture was characterized, and the strength formation mechanism of mixture was explored. The results show that Spontaneous combustion coal gangue has higher activity than Unspontaneous combustion coal gangue.Based on the selected optimal allocation（BNS:SNS:SSC =71.26:9.41:18.8）,The mixture of 4% cement dosage can not only meet the requirement of early strength 4.16 MPa, but also show an efficient strength growth rate of 36.10%, showing the optimum mechanical properties. The total shrinkage coefficient of cement stabilized coal gangue mixture with 4% cement dosage is 1.12×10-2, which shows that the dry shrinkage resistance is the best. With the increase of time, hydration degree is gradually deepened, and gelled substance is more tightly bonded to aggregates. There is no obvious gap between aggregates, and the integrity of the mixture is enhanced, which can show better road performance. Ca (OH)2, a cement hydration product in cement stabilized coal gangue mixture, takes place pozzolana reaction with active SiO2 and Al2O3 in coal gangue to produce gismondine, which is beneficial to the global strength and the bond quality of the mixture.