Journal of transportation engineering
American Society of Civil Engineers
About: Journal of transportation engineering is an academic journal published by American Society of Civil Engineers. The journal publishes majorly in the area(s): Asphalt & Materials science. It has an ISSN identifier of 2573-5438. Over the lifetime, 89 publications have been published receiving 88 citations.
TL;DR: In this article , a more accurate intelligent compaction quality evaluation index is proposed, Acceleration Intelligent Compaction Value (AICV), based on field measurement data analysis, AICV turned out to be effective to elevate quality evaluation accuracy.
Abstract: Compaction Measurement Value (CMV) is the most widely used quality evaluation index for intelligent compaction. However, with the growth of compaction degree, CMV becomes less accurate due to increased reaction force from densified geomaterials. To solve this problem, this paper proposes a more accurate intelligent compaction quality evaluation index, acceleration intelligent compaction value (AICV). Based on field measurement data analysis, AICV turned out to be effective to elevate quality evaluation accuracy. Additionally, the singularities were detected by 3σ normal distribution in order to assess the uniformity of subgrade compaction quality. Based on the semivariogram analysis method of spatial statistics, CMV and AICV were analyzed for spatial correlation, and the influence range of intelligent compaction technology employed for subgrade was evaluated. The results from this study provide a basis for further research on precision control and uniformity analysis of intelligent compaction technology.
TL;DR: In this paper , the effect of asphalt-binder high-temperature rheological properties on hot-mix asphalt rutting performance was investigated using the Texas flexible pavements and overlays database.
Abstract: Asphalt binder is one of the key constitutive components of hot-mix asphalt (HMA) that considerably affects its rutting performance. In particular, the high-temperature rheological properties measured from the multiple stress creep and recovery (MSCR) test are critical for correlating to the HMA rutting resistance. In this study, the Texas flexible pavements and overlays database was used as the data source to investigate the effect of asphalt-binder high-temperature rheological properties on the HMA rutting resistance. The study methodology was based on correlating the results of the MSCR test and the Hamburg wheel-tracking test (HWTT) to HMA field rutting performance. The data matrix for the study included asphalt binder (PG 64-22) from three different sources, three widely used Texas HMA mixes (fine gradation to coarse gradation), and five in-service highway test sections constructed using the same asphalt binders and HMA mixes. In general, the MSCR nonrecoverable creep compliance parameter, Jnrdiff, showed fairly strong correlations with the HMA rutting performance in the laboratory and field. The percent recovery parameter (R), on the other hand, exhibited the potential to ascertain and quantify the presence of modifiers in the asphalt binders. Furthermore, the test results indicated that material source/supplier has an impact on the rheological properties of the asphalt binders with the same performance grade (PG). Overall, the use of the MSCR test to quantify the asphalt-binder high-temperature rheological properties indicated the potential to compliment the laboratory HWTT test for correlating with the field HMA rutting performance in terms of the effects of asphalt binder.
TL;DR: In this paper , the authors investigated the mechanical response of asphalt surfaces under moving traffic loads using the three-dimensional (3D) discrete element method (DEM) and established a discrete element model for asphalt surface based on the random generation algorithm of irregular particles.
Abstract: This paper investigates the mechanical response of asphalt surfaces under moving traffic loads using the three-dimensional (3D) discrete element method (DEM). As an example of a semirigid base asphalt pavement, a discrete element model for asphalt surface was established based on the random generation algorithm of irregular particles in Python language and DEM. The model considered the temperature gradient and fatigue damage to simulate the permanent deformations, shear stresses, and strains in asphalt surfaces under different working conditions (e.g., different temperatures and numbers of repeated loads). Part of the simulation results was verified by performing a full-scale accelerated loading test (ALT). Results show that the 3D discrete element model embedded with temperature gradient and fatigue damage could be used to predict the mechanical response of asphalt surfaces under repeated loads. As the temperature increased, the mechanical response of asphalt surfaces increased. The middle surface was the main area of shear stresses in semirigid base asphalt pavements. Due to fatigue damage, the stresses and strains in asphalt surfaces increased with the number of repeated loads.
TL;DR: In this article , fly ash was used as a replacement for aggregate in the base layer; in the cemented subbase layer, only fly ash and cement were used, and finite element modeling of the test section using PLAXIS 3D version 2013 showed the vertical stress distribution in the inverted pavement.
Abstract: The inverted pavement system is an alternate type of pavement system compared to rigid and flexible pavement systems. The base layer of inverted pavements is generally a cement-treated layer with varied cement content, depending on the unconfined compressive strength criteria and durability. In the present study, fly ash was used as a replacement for aggregate in the cemented base layer; in the cemented subbase layer, only fly ash and cement were used. An optimized combination of fly ash (22%), aggregate (78%), and cement (3%) was used for the cemented base layer. For the cemented subbase layer, 7% cement and 93% fly ash were used. Therefore, 22% aggregate in cemented base and 100% aggregate in cemented subbase layer can be saved. For the field investigation, a test track was constructed for 0.5 million standard axles (MSA), and performance was monitored with both nondestructive testing (NDT), that is, falling weight deflectometer (FWD), Benkelman beam deflection (BBD), and ultrasonic pulse velocity (UPV), and destructive testing (actual loading, plate load test and dynamic cone penetration test) on the test track. The NDT testing showed that the cemented layers performed well. However, it was found that the pavement failed prematurely under actual loading. The plate load test showed that crack relief failed because of compaction issues. Last, finite-element modeling of the test section using PLAXIS 3D version 2013 showed the vertical stress distribution in the inverted pavement.