scholarly journals Linking the Effect of Aggregate Interaction to the Compaction Theory for Asphalt Mixtures Using Image Processing

2018 ◽  
Vol 8 (11) ◽  
pp. 2045 ◽  
Author(s):  
Kyoungchul Kim ◽  
Myungook Kang
Keyword(s):  
Image Processing ◽  
High Temperature ◽  
Asphalt Binder ◽  
Asphalt Mixtures ◽  
Energy Index ◽  
Optimum Temperature ◽  
Frictional Behavior ◽  
Viscosity Effect ◽  
Frictional Interaction ◽  
Compaction Energy

This study presents a modified compaction concept of asphalt mixtures based on aggregate frictional behavior using self-developed image processing for measuring the aggregate orientation. The compaction energy index was introduced to evaluate the aggregate orientation on different compaction temperatures. For the better rearrangement of aggregates, there was an optimum temperature at which a preferred orientation exists, providing lower compaction efforts. An excessively high temperature reduced the asphalt contents for lubrication and caused additional aggregate friction to require higher compaction efforts. This phenomenon can be found in the changes of the volume of the effective asphalt binder (Veac) and the absorbed asphalt binder (Pba). The mixture produced higher Veac, at which an optimum compaction temperature required lower compaction energy. Despite being higher than the optimum temperature for the PG62-28 mixture, the Veac decreased by 0.4%. An increase of 0.35% in the Pba was inferred to flow into the aggregates. Clearly, a reduction of lubricant in the mixture caused a higher frictional interaction between aggregates. Changes in the Veac and the Pba can eliminate the viscosity effect for the rearrangement of aggregates. Based on the aggregate orientation and change in mixture volumetrics, the aggregate interaction effect was introduced to the Mohr–Coulomb compaction theory to explain the additional friction.

scholarly journals Cold In-Place Recycling Asphalt Mixtures: Laboratory Performance and Preliminary M-E Design Analysis

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2036
Author(s):  
Dongzhao Jin ◽  
Dongdong Ge ◽  
Siyu Chen ◽  
Tiankai Che ◽  
Hongfu Liu ◽  
...  
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Dynamic Modulus ◽  
Asphalt Pavement ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Asphalt Emulsion ◽  
Moisture Susceptibility ◽  
Low Temperature Cracking

Cold in-place recycling (CIR) asphalt mixtures are an attractive eco-friendly method for rehabilitating asphalt pavement. However, the on-site CIR asphalt mixture generally has a high air void because of the moisture content during construction, and the moisture susceptibility is vital for estimating the road service life. Therefore, the main purpose of this research is to characterize the effect of moisture on the high-temperature and low-temperature performance of a CIR asphalt mixture to predict CIR pavement distress based on a mechanistic–empirical (M-E) pavement design. Moisture conditioning was simulated by the moisture-induced stress tester (MIST). The moisture susceptibility performance of the CIR asphalt mixture (pre-mist and post-mist) was estimated by a dynamic modulus test and a disk-shaped compact tension (DCT) test. In addition, the standard solvent extraction test was used to obtain the reclaimed asphalt pavement (RAP) and CIR asphalt. Asphalt binder performance, including higher temperature and medium temperature performance, was evaluated by dynamic shear rheometer (DSR) equipment and low-temperature properties were estimated by the asphalt binder cracking device (ABCD). Then the predicted pavement distresses were estimated based on the pavement M-E design method. The experimental results revealed that (1) DCT and dynamic modulus tests are sensitive to moisture conditioning. The dynamic modulus decreased by 13% to 43% at various temperatures and frequencies, and the low-temperature cracking energy decreased by 20%. (2) RAP asphalt incorporated with asphalt emulsion decreased the high-temperature rutting resistance but improved the low-temperature anti-cracking and the fatigue life. The M-E design results showed that the RAP incorporated with asphalt emulsion reduced the international roughness index (IRI) and AC bottom-up fatigue predictions, while increasing the total rutting and AC rutting predictions. The moisture damage in the CIR pavement layer also did not significantly affect the predicted distress with low traffic volume. In summary, the implementation of CIR technology in the project improved low-temperature cracking and fatigue performance in the asphalt pavement. Meanwhile, the moisture damage of the CIR asphalt mixture accelerated high-temperature rutting and low-temperature cracking, but it may be acceptable when used for low-volume roads.

Laboratory evaluation on the high temperature rheological properties of rubber asphalt: a preliminary study

2012 ◽  
Vol 39 (10) ◽  
pp. 1125-1135 ◽  
Author(s):  
Hainian Wang ◽  
Zhanping You ◽  
Shu Wei Goh ◽  
Peiwen Hao ◽  
Xiaoming Huang
Keyword(s):  
High Temperature ◽  
Rheological Properties ◽  
Rubber Particle ◽  
Asphalt Binder ◽  
Field Performance ◽  
Crumb Rubber ◽  
Testing Temperature ◽  
Asphalt Mixtures ◽  
Laboratory Evaluation ◽  
Loading Frequency

Crumb rubber is the recycled rubber particle obtained from mechanical shearing or grinding scrap tires into small particle sizes less than 6.3 mm (or approximately 1/4”). The rheological properties of asphalt binder have an important effect on the field performance of asphalt mixtures and the long-term serviceability of asphalt pavement. The objective of this research is to evaluate the high temperature rheological performance of rubber asphalt binder based on the complex shear modulus (|G*|) and the phase angle (δ) values using the dynamic shear rheometer. Five rubber asphalt dosages at 0, 10, 15, 20, and 25% by weight of asphalt (Superpave PG 64-22), respectively, were used to modify asphalt binder; and three rubber particle meshes, 20#, 30#, and 40#, were utilized in this research. The |G*| at various temperatures and frequencies were tested on each sample, including original and short-term aging binder using the rolling thin-film over. The master curves of |G*|/sin(δ) for each type of rubber asphalt was generated to investigate its rheological properties over a broad range of temperatures and frequencies. Based on the testing results, it was found that the addition of crumb rubber significantly increases the |G*| of asphalt binder, which is desirable to potentially improve the anti-rutting performance of asphalt mixtures. It was also found that the addition of 10% mesh crumb rubbers bumps up the high temperature grade of asphalt, from PG64 to PG76 in this case. The master curve using the |G*|/sin(δ) of rubber asphalt shows a substantial improvement in rutting resistant at each testing temperature and loading frequency. However, it was noteworthy that the rutting resistance enhancement of crumb rubber was affected by the percentage of rubber used, the rubber particle size and its aging condition.

scholarly journals Characterization of asphalt binders extracted from field mixtures containing RAP and/or RAS

2022 ◽  
Vol 13 (1) ◽  
pp. 140-152
Author(s):  
Eslam Deef-Allah ◽  
Magdy Abdelrahman
Keyword(s):  
High Temperature ◽  
Rheological Properties ◽  
Asphalt Binder ◽  
Asphalt Mixtures ◽  
Asphalt Binders ◽  
Creep Recovery ◽  
Recycled Asphalt ◽  
Reclaimed Asphalt ◽  
Multiple Stress Creep Recovery ◽  
Pavement Construction

The use of reclaimed asphalt pavement (RAP) and/or recycled asphalt shingles (RAS) in the asphalt mixtures is a common practice in the U.S.A. However, there is a controversy to date on how RAP/RAS interact with virgin asphalt binders (VABs) in asphalt mixtures. For mixtures containing RAP/RAS, the aged asphalt binders in RAP and air-blown asphalt binders in RAS alter the performances of the extracted asphalt binders (EABs). Thus, the rheological properties of EABs from these mixtures require more investigation. The focus of this paper was relating the high-temperature properties of EABs from field cores to the corresponding rolling thin film oven aged virgin asphalt binders (RTFO AVABs). Furthermore, a comparison of the effect of RAP and RAS on the high-temperature rheological properties of EABs was another objective. Different asphalt cores were collected from the field within two weeks after the pavement construction process in 2016. These cores represented eight asphalt mixtures with different asphalt binder replacement percentages by RAP, RAS, or both. The asphalt binders were extracted from these mixtures and considered as RTFO AVABs. The high-temperature rheological properties included the temperature sweep and frequency sweep testing and the multiple stress creep recovery testing. The EABs had higher stiffnesses and elasticates than the corresponding RTFO AVABs because of the aged binders in RAP/RAS. The binders in RAP interacted more readily with VABs than RAS binders.

Stability of Asphalt Binder and Asphalt Mixture Modified by Polyacrylonitrile Fibers

2011 ◽  
Vol 228-229 ◽  
pp. 242-247 ◽  
Author(s):  
Li Yang Yao ◽  
Yun Peng Hu ◽  
Qin Ma ◽  
Xian Wei Ma
Keyword(s):  
High Temperature ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Methyl Cellulose ◽  
Temperature Stability ◽  
Asphalt Mixtures ◽  
Pavement Performance ◽  
Polyacrylonitrile Fiber ◽  
High Temperature Stability ◽  
Temperature Crack

The research was conducted to evaluate pavement properties of polyacrylonitrile fiber asphalt binder and asphalt mixtures, including high temperature stability of binder and mixture, low temperature crack resistance and water stability of mixture. Moreover, polyacrylonitrile fibers were compared with methyl cellulose in the asphalt binder and asphalt mixtures. The result indicates that polyacrylonitrile fibers may improve clearly the high temperature stability of asphalt binder, and pavement performance of mixtures is enhanced obviously. Also polyacrylonitrile fiber binder and mixtures have better performance than methyl cellulose.

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.

scholarly journals Greener Solution to Waste Corn Stalks and Shortage of Asphalt Resource: Hydrochar Produced by Hydrothermal Carbonization as a Novel Performance Enhancer for Asphalt Binder

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1427
Author(s):  
Xiaoming Wu ◽  
Chichun Hu
Keyword(s):  
High Temperature ◽  
Reaction Temperature ◽  
Storage Stability ◽  
Asphalt Binder ◽  
Aging Effect ◽  
Experimental Tests ◽  
Hydrothermal Carbonization ◽  
Modified Asphalt ◽  
Direct Combustion ◽  
Aging Property

Utilization of waste corn stalks (CS) has seized extensive attention due to high annual output and hazardous impact of piling aside or direct combustion on environment. However, previously there has been a lot of emphasis on improvement of its energy efficiency as solid fuel while limited investigations are available which explore the possibility of applying corn stalks as performance enhancer in asphalt binder. The purpose of this study is to examine the potential of employing hydrochar as modifiers in asphalt binder by a series of experimental tests. In this study, two hydrochar were produced from corn stalks by a novel process called hydrothermal carbonization at a different reaction temperature. The two hydrochar and their responding hydrochar-modified asphalt (HCMA) were tested by chemical and rheological tests. Chemical analysis detected the interaction between hydrochar and binder factions, resulting in poor compatibility but satisfying anti-aging property. Even though hydrochar increased the viscosity of bitumen, implying worse workability, and caused poor storage stability, ameliorated performance of asphalt binder at high temperature by incorporating hydrochar was verified by various criteria such as higher performance grade (PG) failure temperature and lower non-recoverable creep compliance (Jnr). Moreover, higher reaction temperature makes hydrochar’s particles smaller and more homogeneous, which results in slightly lower enhanced high temperature performance, more satisfying workability, better storage stability, and greater anti-aging effect of hydrochar-modified asphalt. Eventually, this study provided a promising win-win solution to environment problems concerning corn stalk treatment and shortage of asphalt binder. Further exploration of methods to improve HCMA’s storage stability, real-scale corroboration on trial section and life cycle assessment of asphalt pavement containing hydrochar modifiers will be followed in the future.

Investigating the influence of carbon nanotube on the performance of asphalt binder

2021 ◽  
pp. 147776062110194
Author(s):  
Peerzada Mosir Shah ◽  
Mohammad Shafi Mir
Keyword(s):  
High Temperature ◽  
Asphalt Binder ◽  
Storage Condition ◽  
Modified Bitumen ◽  
Creep And Recovery ◽  
Low Viscosity ◽  
Temperature Performance ◽  
Modified Asphalt Binder ◽  
Viscosity Grade ◽  
The Impact

The purpose of this study aims at investigating the impact of multi-walled carbon nanotubes (MWCNT’s) on the properties of low viscosity grade asphalt binder. Asphalt binder with viscosity grade-10 is selected as the control binder and later it is modified with different percentages of MWCNT’s (0.5–2.5%). Penetration, softening point, ductility and rotational viscosity test were employed for evaluating the effect of MWCNT’s on basic physical properties of modified asphalt binder. Dynamic Shear Rheometer (DSR) is used for evaluating the rheological properties of the base and modified bitumen, for both aged and unaged bitumen. Based on the conventional and basic rheological tests, it was seen that the addition of MWCNT’s improved the high-temperature performance of modified bitumen. Multiple Stress Creep and Recovery (MSCR) test results revealed that the addition of MWCNT’s improved the creep and recovery of modified binders for both stress intensities (0.1 kPa and 3.2 kPa) which confirms that the modified binder is more rut resistant. Moreover, it was observed that there was a significant improvement in the aging resistance of the asphalt binder due to addition of MWCNTs. However low temperature performance of MWCNTs was not encouraging. Also, MWCNTs addition to asphalt binder was found to be stable under high-temperature storage condition. Overall, there is a significant amount of improvement using MWCNTs in the base asphalt binder.

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.

Sign in / Sign up

Export Citation Format

Share Document