Meso-Scale Kinematic Responses of Asphalt Mixture in Both Field and Laboratory Compaction

2021 ◽  
pp. 036119812110092
Author(s):  
Xue Wang ◽  
Shihui Shen ◽  
Hai Huang
Keyword(s):  
Angular Position ◽  
Asphalt Mixture ◽  
Movement Pattern ◽  
Position Change ◽  
Pneumatic Tire ◽  
Field Compaction ◽  
Gyratory Compaction ◽  
Pavement Construction ◽  
Rolling Wheel ◽  
Meso Scale

Compaction is one of the most critical steps in asphalt pavement construction. Traditional compaction relies heavily on engineering experience and post-construction quality control and can lead to under/over compaction problems. The emerging intelligent compaction technology has improved compaction quality but is still not successful in obtaining mixture properties of a single pavement layer. Besides, very few studies have discussed the internal material responses during field and laboratory compaction to explain the meso-scale (i.e., particle scale) compaction mechanism. Knowledge in those areas may greatly promote the development of smart compaction. Therefore, this study aims to investigate the kinematic behavior of the asphalt mixture particles (translation and rotation) under six types of field and laboratory compaction methods and establish the relationship between the field and the laboratory compaction by using a real-time particle motion sensor, SmartRock. It was found that particle movement pattern was mainly affected by the compaction mode. At the meso-scale where particle behavior is the focus, the kneading effects of a pneumatic-tire roller can be simulated by laboratory gyratory and rolling wheel compaction, and the vibrating effects of a vibratory roller can be simulated by Marshall compaction. However, none of those laboratory compaction methods can completely simulate the field compaction. Under vibratory rolling, particle acceleration decreased fast in the breakdown rolling stage. Under pneumatic-tire rolling, particle angular position change was related to aggregate skeleton, and particle relative rotation showed a decreasing trend that was consistent with the laboratory gyratory compaction results. Those kinematic responses can potentially be used to monitor density change in field compaction.

scholarly journals Evaluating Gyratory Compaction Characteristics of Unbound Permeable Aggregate Base Materials from Meso-Scale Particle Movement Measured by Smart Sensing Technology

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4287
Author(s):  
Yuanjie Xiao ◽  
Meng Wang ◽  
Xiaoming Wang ◽  
Juanjuan Ren ◽  
Weidong Wang ◽  
...  
Keyword(s):  
Motion Sensors ◽  
Particle Movement ◽  
Compaction Process ◽  
Movement Characteristics ◽  
Macro Scale ◽  
Field Compaction ◽  
Gyratory Compaction ◽  
Scale Particle ◽  
Meso Scale

The quality of compaction of unbound aggregate materials with permeable gradation plays a vital role in their field performance; however, there are currently few unanimously accepted techniques or quality control criteria available for ensuring adequate compaction of such materials in either laboratory or field applications. This paper presented testing results of a laboratory gyratory compaction study where the combinations of gyratory parameters were properly designed using the orthogonal array theory. Innovative real-time particle motion sensors were employed to record particle movement characteristics during the compaction process and provide a meso-scale explanation about compaction mechanisms. Particle abrasion and breakage were also quantified from particle shape digitized from the three-dimensional (3D) laser scanner before and after compaction. The optimal combination of gyratory parameters that yields the best compaction performance was determined from the orthogonal testing results with the relative importance of major influencing parameters ranked accordingly. Meso-scale particle movement at the upper center and center side positions of the specimen are promising indicators of compaction quality. The gyratory compaction process can be consistently divided into three distinct stages according to both macro-scale performance indicators and meso-scale particle movement characteristics. A statistically significant bi-linear relationship was found to exist between relative breakage index and maximum abrasion depth, whereas the quality of compaction and the extent of particle breakage appear to be positively correlated, thus necessitating the cost-effective balance between them. The results of this study could provide technical insights and guidance to field compaction of unbound permeable aggregates.

scholarly journals Experimental and Numerical Analysis on Mesoscale Mechanical Behavior of Coarse Aggregates in the Asphalt Mixture during Gyratory Compaction

Processes ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 47
Author(s):  
De Zhang ◽  
Zhiqiang Cheng ◽  
Dajiang Geng ◽  
Shengjia Xie ◽  
Tao Wang
Keyword(s):  
Contact Stress ◽  
Positive Impact ◽  
Asphalt Mixture ◽  
Contact Forces ◽  
Normal Contact ◽  
Coarse Aggregates ◽  
Stress Rotation ◽  
Gyratory Compaction ◽  
Internal Angle ◽  
Pavement Construction

Compaction is a critical step in asphalt pavement construction. The objective of this study is to analyze the mesoscale mechanical behaviors of coarse aggregates in asphalt mixtures during gyratory compaction through experiments and numerical simulation using the Discrete Element Method (DEM). A novel granular sensor (SmartRock) was embedded in an asphalt mixture specimen to collect compaction response data, including acceleration, stress, rotation angle and temperature. Moreover, the irregularly shaped coarse aggregates were regenerated in the DEM model, and numerical simulations were conducted to analyze the evolution of aggregate interaction characteristics. The findings are as follows: (1) the measured contact stress between particles changes periodically during gyratory compaction, and the amplitude of stress tends to be stable with the increase of compaction cycles; (2) the contact stress of particles is influenced by the shape of aggregates: flat-shaped particles are subjected to greater stress than angular, fractured or elongated particles; (3) the proportion of strong contacts among particles is high in the initial gyratory compaction stage, then decreases as the number of gyratory compactions grows, the contacts among particles tending to homogenize; (4) during initial gyratory compactions, the normal contact forces form a vertical distribution due to the aggregates’ gravity accumulation. The isotropic distribution of contact forces increases locally in the loading direction along the axis with a calibrated internal angle orientation (1.25°) in the earlier cyclic loading stage, then the local strong contacts decrease in the later stage, while the strength of the force chains in other directions increase. The anisotropy of aggregate contact force networks tends to weaken. In other words, kneading and shearing action during gyratory compaction have a positive impact on the homogenization and isotropy of asphalt mixture contact forces.

A Hybrid Model to Predict the Gyratory Compaction of Hot Mixed Asphalt

2019 ◽  
Author(s):  
Teng Man
Keyword(s):  
Hybrid Model ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Aggregate Size ◽  
Asphalt Mixtures ◽  
Compaction Process ◽  
Particle Rearrangement ◽  
Compaction Behavior ◽  
Grain Size Distributions ◽  
Gyratory Compaction

The compaction of asphalt mixture is crucial to the mechanical properties and the maintenance of the pavement. However, the mix design, which based on the compaction properties, remains largely on empirical data. We found difficulties to relate the aggregate size distribution and the asphalt binder properties to the compaction behavior in both the field and laboratory compaction of asphalt mixtures. In this paper, we would like to propose a simple hybrid model to predict the compaction of asphalt mixtures. In this model, we divided the compaction process into two mechanisms: (i) visco-plastic deformation of an ordered thickly-coated granular assembly, and (ii) the transition from an ordered system to a disordered system due to particle rearrangement. This model could take into account both the viscous properties of the asphalt binder and grain size distributions of the aggregates. Additionally, we suggest to use the discrete element method to understand the particle rearrangement during the compaction process. This model is calibrated based on the SuperPave gyratory compaction tests in the pavement lab. In the end, we compared the model results to experimental data to show that this model prediction had a good agreement with the experiments, thus, had great potentials to be implemented to improve the design of asphalt mixtures.

Coir fiber as a sustainable material in pavement construction.

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Anjaly M.
Keyword(s):  
Natural Fibers ◽  
Asphalt Mixture ◽  
Fatigue Cracking ◽  
Performance Characteristics ◽  
Traffic Density ◽  
Coir Fiber ◽  
Sustainable Material ◽  
Stone Matrix Asphalt ◽  
Pavement Construction ◽  
Stone Matrix

ABSTRACT Traffic is increasing day by day due to increased vehicle ownership and infrastructure development. As the modern highway transportation has high speed, high traffic density, heavy load and channelized traffic, bituminous concrete is subjected to various types of distress such as rutting, fatigue cracking and raveling. Fatigue cracking occurs because bituminous layers are weak in tension. Therefore reinforcement of the bituminous mixes is one approach to improve tensile strength. Natural fibers can be used for reinforcing as a substitute for synthetic fibers due to their lower cost, ecological recycling and low specific gravity. Among natural fibers growing attention is being paid to coir fiber due to its easy availability, good wearing resistance and more durable property. Also rutting along wheel path causes vehicle hydroplaning during rainy seasons due to loss of skid resistance. As well as water accumulated over the longitudinal depressions damages bond between binder and aggregates. Therefore there is a need for a durable mix which can increase the service life of pavement thus reduces life cycle cost. This study is about use of coir fiber in pavement construction to improve the performance characteristics of the asphalt mixture being used. Stone matrix asphalt mixture is a rut resistant and durable mix which is reinforced with coir fiber and tested for various performance characteristics. Coir fiber is a sustainable material which can be used for rutting resistant mixture.   Keywords: Stone matrix asphalt, Coir fiber, rutting

Determining Optimum Carbon Nanotubes Content for Asphalt Mixture in Road Pavements

2021 ◽  
Vol 1023 ◽  
pp. 121-126
Author(s):  
Van Bach Le ◽  
Van Phuc Le
Keyword(s):  
Carbon Nanotubes ◽  
Asphalt Pavement ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Construction Cost ◽  
Asphalt Mixtures ◽  
Static Modulus ◽  
Pavement Construction ◽  
Modified Binder ◽  
Marshall Stability

Although small amount of binder in asphalt concrete mixture may commonly range from 3.5 to 5.5% of total mixture as per many international specifications, it has a significant impact on the total cost of pavement construction. Therefore, this paper investigated the effects of five carbon nanotubes contents of 0.05%, 0.1%, 0.15%, 0.2%, 0.25% by asphalt weight as an additive material for binder on performance characteristics of asphalt mixtures. Performance properties of CNTs modified asphalt mixtures were investigated through the Marshall stability (MS) test, indirect tensile (IDT) test, static modulus (SM) test, wheel tracking (WT) test. The results indicated that asphalt mixtures with CNT modified binder can improve both the rutting performance, IDT strength and marshall stability of tested asphalt mixtures significantly at higher percentages of carbon nanotubes. However, the issue that should be considered is the construction cost of asphalt pavement. Based on the asphalt pavement structural analysis and construction cost, it can be concluded that an optimum CNT content of 0.1% by asphalt weight may be used as additive for asphalt binder in asphalt mixtures.

scholarly journals Comparative study on combustion characteristics of lean premixed CH4/air mixtures in RCM using spark ignition and turbulent jet ignition in terms of orifices angular position change

2019 ◽  
Vol 176 (1) ◽  
pp. 36-41 ◽  
Author(s):  
Wojciech BUESCHKE ◽  
Maciej SKOWRON ◽  
Krzysztof WISŁOCKI ◽  
Filip SZWAJCA
Keyword(s):  
Internal Combustion Engines ◽  
Positive Impact ◽  
Angular Position ◽  
Turbulent Jet ◽  
Combustion Stability ◽  
Optical Observations ◽  
Charge Movement ◽  
Position Change ◽  
Lean Burn ◽  
The Impact

The increase in ignitability consist a main aim of implementation of the turbulent jet ignition (TJI) in relation to the combustion of diluted charges. Such an ignition system has been introduced to the lean-burn CNG engine in the scope of GasOn-Project (Gas Only Internal Combustion Engines). In this study the impact of TJI application on the main combustion indexes has been investigated using RCM and analyzed on the bases of the indicating and optical observations data. The images have been recorded using LaVision HSS5 camera and post-processed with Davis software. Second part of the study based on indicating measurements consist the analysis of combustion regarding the variation in the geometry of pre-chamber nozzles. It has been noted, that combustion with TJI indicates signi- ficantly bigger flame luminescence and simultaneously – faster flame front development, than the combustion initiated with conventional SI. The positive impact of nozzles angular position on engine operational data has been found in the static charge movement conditions, regarding the combustion stability.

scholarly journals The Durability of the AC-BC Mixture Using Stone of Baba Mount, Tana Toraja Regency

2021 ◽  
Vol 3 (3) ◽  
pp. 69-75
Author(s):  
Cindy Pasilaputri ◽  
Alpius ◽  
Louise Elizabeth Radjawane
Keyword(s):  
Immersion Time ◽  
Asphalt Mixture ◽  
Immersion Test ◽  
Test Method ◽  
Traffic Load ◽  
Technical Requirements ◽  
High Durability ◽  
Marshall Test ◽  
Pavement Construction

Several factors that can affect road damage are excessive traffic load, temperature (weather), water, and pavement construction that does not meet the technical requirements. The durability of an asphalt mixture is the resistance of the mixture to the effects of water, water vapor, and temperature. A mixture with a high durability value provides a good mix quality and long-term use. The purpose of this study was to determine the durability of the AC-BC mixture using Mount Baba stone. The general specifications of Bina Marga in 2018 are the reference in this study. By using the standard Marshall test method, the results obtained through the Marshall AC-BC mixture immersion test with a duration of immersion time of 0.5 hours, 12 hours, 24 hours, 36 hours, 48 hours, 60 hours with a durability value of 95.49% - 86.99%. The increase in immersion time causes a decrease in the durability of the mixture.

scholarly journals Additive Percent Influence on “Warm Mix” Behavior

2014 ◽  
Vol 3 (1) ◽  
pp. 35-42
Author(s):  
Carmen Răcănel ◽  
Adrian Burlacu
Keyword(s):  
Sustainable Development ◽  
Working Conditions ◽  
Hot Mix Asphalt ◽  
New Technology ◽  
Asphalt Mixture ◽  
Master Curves ◽  
Stiffness Modulus ◽  
Chemical Additive ◽  
The Road ◽  
Field Compaction

Abstract The benefits of WMA technologies include reduced fuel usage and emissions in support of sustainable development, improved field compaction, which can facilitate longer haul distances and cool weather pavement, and better working conditions. Since this is a relatively new technology, it is necessary to determine the behavior and the performances of this type of asphalt mixture depending on additive percent. These technologies tend to reduce the viscosity of the asphalt and provide for the complete coating of aggregates at lower temperatures. WMA is produced at temperatures 20 to 30°C lower than typical hot-mix asphalt (HMA). The paper presents the results obtained in the Road Laboratory of Technical University of Civil Engineering Bucharest on an asphalt mixture with fibers (MASF16) prepared according to the “warm mix” technology with chemical additive. Different percent of additive are used in laboratory to draw up the “master curves” of asphalt mixture obtained by 4PB-PR stiffness modulus results.

scholarly journals How Can Sustainable Materials in Road Construction Contribute to Vehicles’ Braking?

Vehicles ◽  
2020 ◽  
Vol 2 (1) ◽  
pp. 55-74 ◽  
Author(s):  
Maria Pomoni ◽  
Christina Plati ◽  
Andreas Loizos
Keyword(s):  
Asphalt Mixture ◽  
Road Construction ◽  
Seasonal Temperature ◽  
Reclaimed Asphalt ◽  
Frictional Properties ◽  
Key Factor ◽  
Sustainable Materials ◽  
Materials Used ◽  
Pavement Construction ◽  
Pavement Friction

Vehicles’ braking is a key factor towards safer driving. In particular, tyre–pavement friction is connected with both industry and infrastructure requirements in terms of tyre characteristics and frictional properties of pavement surfaces respectively that both contribute to safe braking. For this reason, tyre–pavement friction is considered as one of the most pressing emergencies in roadway assets in order to reduce skidding related accidents. At the same time, sustainability aspects have been raised in modern infrastructure engineering. Hence, an issue is introduced on how sustainable materials used for pavement construction may contribute to tyre–pavement and consequently vehicles’ braking. For this reason, a laboratory process is developed to investigate the frictional properties of several utilized in pavement wearing courses including both traditional and sustainable materials (reacted activated rubber—RAR and reclaimed asphalt pavement—RAP). Environmental conditions (seasonal temperature changes, rainfall effect and contamination caused by dust formation) are simulated in the laboratory and vehicles’ braking is investigated using the British Pendulum Tester (BPT). Results provide a good explanation for the vehicles’ braking ability under the investigated conditions for both traditional and sustainable materials. Ultimately, it is proved that asphalt mixture types with RAR modifier or RAP material exhibit a satisfactory performance towards providing a safe road surface for the moving vehicles.

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