Analytical Formulas for Film Thickness in Compacted Asphalt Mixture

2003 ◽  
Vol 1829 (1) ◽  
pp. 26-32 ◽  
Author(s):  
Boris Radovskiy
Keyword(s):  
Film Thickness ◽  
Asphalt Concrete ◽  
Volume Fraction ◽  
Asphalt Mixture ◽  
Modern Technology ◽  
Asphalt Mixtures ◽  
Statistical Geometry ◽  
Arbitrary Size ◽  
Analytical Formulas ◽  
Asphalt Film

Recently, several researchers have proposed asphalt film thickness as a criterion for ensuring the durability of asphalt mixtures. However, they suggested that the standard film thickness equation, which dates back to the 1940s, needs to be examined by modern technology and improved. A presumable background on which the Asphalt Institute surface area factors are based was recovered and analyzed in detail. A fundamentally sound model for film thickness calculation was developed using a model of asphalt concrete in which the aggregates are spherical but have an arbitrary size distribution. A recent result from statistical geometry is applied to determine the film thickness for any volume fraction of aggregates and any volume fraction of effective asphalt. The analytical formulas are presented, the details of the calculation are summarized, and examples are provided.

scholarly journals Determination of Construction Parameters of Porous Ultra-Thin Overlays Based on Laboratory Compaction Studies

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4496
Author(s):  
Jiahao Tian ◽  
Sang Luo ◽  
Ziming Liu ◽  
Xu Yang ◽  
Qing Lu
Keyword(s):  
Asphalt Concrete ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Combination Method ◽  
Compaction Temperature ◽  
Pavement Maintenance ◽  
Energy Equivalence ◽  
New Type ◽  
Better Than

To address the severe distresses of asphalt pavement, a new type of pavement maintenance treatment, porous ultra-thin overlay (PUTO) with small particle size was proposed. The PUTO has a thickness of 1.5–2.5 cm and a large void ratio of 18–25%. As a newly asphalt mixture, the structure characteristics differ from poor traditional pavement. Therefore, it is necessary to investigate the fabrication schemes in laboratory and on-site, respectively. In this study, the optimal fabrication schemes, including compaction temperature and number of blows of PUTO were determined based on Cantabro test and volumetric parameters. Then, the corresponding relationship between laboratory and on-site compaction work was then established based on the energy equivalent principle. On this basis, the numbers of on-site rolling passes and the combination method were calculated. The results show that increased compaction temperature and number of blows reduce the height and enhance the compaction of the Marshall sample. With the same temperature and number of blows, the raveling resistance of coarse gradation, Pavement Asphalt Concrete-1 (PAC-1) is better than that of fine gradation, Pavement Asphalt Concrete-2 (PAC-2), and the increased asphalt viscosity significantly improves the raveling resistance of the asphalt mixture. To ensure the scattering resistance and volumetric characteristic, the initial compaction temperature of the PAC-1 and PAC-2 should not be lower than 150 °C and 165 °C, respectively. Then, the laboratory compaction work and on-site compaction work were calculated and converted based on the principle of energy equivalence. Consequently, the on-site compaction combination of rolling machines for four asphalt mixtures was determined. According to the volumetric parameters, the paving test section proved that the construction temperature and the on-site rolling combination determined by laboratory tests are reasonable, and ultra-thin overlay has good structural stability, drainage, and skid resistance.

Investigation of In-Place Asphalt Film Thickness and Performance of Hot-Mix Asphalt Mixtures

2009 ◽  
Vol 21 (6) ◽  
pp. 262-270 ◽  
Author(s):  
Xinjun Li ◽  
R. Christopher Williams ◽  
Mihai O. Marasteanu ◽  
Timothy R. Clyne ◽  
Eddie Johnson
Keyword(s):  
Film Thickness ◽  
Hot Mix Asphalt ◽  
Asphalt Mixtures ◽  
And Performance ◽  
Asphalt Film

Study of Road Property of Basalt Fiber Asphalt Concrete

2012 ◽  
Vol 238 ◽  
pp. 22-25 ◽  
Author(s):  
Yuan Zhao Chen ◽  
Zhen Xia Li
Keyword(s):  
Asphalt Concrete ◽  
Asphalt Mixture ◽  
Basalt Fiber ◽  
Temperature Stability ◽  
Asphalt Mixtures ◽  
Polyester Fiber ◽  
Pavement Performance ◽  
High Temperature Stability ◽  
Reference Mixture ◽  
Temperature Crack

In order to discuss the effectiveness of basalt fiber in reinforcing pavement performance of asphalt mixtures, the pavement performances of basalt fiber asphalt mixtures were investigated by tests of high temperature stability, water stability and low temperature crack resistance, and compared with the pavement performance of asphalt mixtures with polyester fiber and xylogen fiber, and that of reference mixture. The results show that pavement performance of fiber asphalt mixture are improved and optimized comparing with reference asphalt mixture, the performance of asphalt mixture with basalt fiber are excelled than those with polyester fiber and xylogen fiber while the dosage of fibers is keeping at the optimum.

scholarly journals Determination of temperature regimes of producing of mastic asphalt concrete mixtures on bitumen binders of different consistency

2021 ◽  
Vol 2 (92) ◽  
pp. 51
Author(s):  
Serhii Oksak
Keyword(s):  
Asphalt Concrete ◽  
Research Work ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Limestone Powder ◽  
Mixture Component ◽  
Mastic Asphalt ◽  
Temperature Regimes ◽  
High Tempera Ture ◽  
The One

Abstract. Problem. The temperature of mastic as-phalts mixing is significantly higher than the one for hot asphalt mixtures. It is due using of high viscous bitumens as a mixture component and realizing the main advantage of mastic asphalt – its ability to flow and compact with its own weight at high tempera-ture. There is no uniform way to assign the process temperatures for mastic asphalt. Goal. To find the process temperatures for mastic asphalt with bitumen binders differ by viscosity as a researching on tem-perature influence and influence of binder concentra-tion on properties of mastic asphalt is a goal of this research work. Methodology. The mastic asphalt mixtures and asphalt concrete with conventional pavement bitumen 70/100 (penetration is 85 dmm) and high viscous bitumen (penetration is 38 dmm) are chosen for research. The mineral aggregates contain 42 % of crushed granite 5-10 mm, 33 % of granite screening and 33 % of limestone powder. The properties of mastic asphalts are evaluated with EN 12697-20:2003, SOU 42.1-37641918-106:2013 and DSTU EN 13108-6:2018. Results. It was found a significant influence of amount and viscosity of bitu-men and a temperature on workability of mastic as-phalt mixture and on properties of mastic asphalt concrete. Originality. The comparative analysis of workability of mastic asphalt mixture and properties of mastic asphalt concrete with bitumens differ in viscosity is a scientific originality of presented re-search. Practical value. Due to research results it is not reasonable to assign the temperature that sup-plies viscosity of 0.5 Pa•s as a temperature of mixing of mastic asphalt. The temperature conditions of mastic asphalt mixing are much higher (200 – 240 °C). To evaluate workability and find a minimal acceptable temperature of mixture it is possible to use the thickness of the mixture layer after spreading as an indicator. With this the acceptable workability of the mastic asphalt mixture can be characterized by thickness of its layer 30 mm or less after spreading.

Evaluation of Pyrolized Carbon Black from Scrap Tires as Additive in Hot Mix Asphalt

1996 ◽  
Vol 1530 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Taesoon Park ◽  
Brian J. Coree ◽  
C. W. Lovell
Keyword(s):  
Carbon Black ◽  
Asphalt Concrete ◽  
Resilient Modulus ◽  
Testing Machine ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Test Results ◽  
Reinforcing Agent ◽  
Dynamic Creep ◽  
Temperature Susceptibility

The viability of using pyrolized carbon black (CBp) derived from waste tires as a reinforcing agent in asphalt mixtures was evaluated. Commercial carbon black (CB) has been previously shown to reduce the rutting resistance, temperature susceptibility, and cracking propagation potential of asphalt concrete. It was believed that CBp could produce similar benefits; this belief has been confirmed by this study. Different ratios of CBp and CB (5, 10, 15, and 20 percent by weight of asphalt) were blended with two grades of asphalt (AC-10 and AC-20). The Marshall method, the gyratory testing machine, the dynamic creep testing (confined), the indirect tensile testing, and the resilient modulus test were performed. The test results of CBp mixtures were compared with results of CB and conventional mixtures. The analyses of test results show that the typical performance of CBp-modified asphalt mixtures is improved with respect to commercial CB and conventional mixtures. The rutting potential and the temperature susceptibility can be reduced by the inclusion of CBp in the asphalt mixture. A CBp content of 10 to 15 percent by weight of asphalt is recommended for improvement of asphalt concrete.

scholarly journals Influence of Polypropylene Length on Stability and Flow of Fiber-reinforced Asphalt Mixtures

2016 ◽  
Vol 2 (10) ◽  
pp. 538-545 ◽  
Author(s):  
Ramin Bayat ◽  
Siamak Talatahari
Keyword(s):  
Asphalt Concrete ◽  
Asphalt Pavement ◽  
Flexible Pavements ◽  
Asphalt Mixture ◽  
Fatigue Cracking ◽  
Asphalt Mixtures ◽  
Concrete Mixture ◽  
Fiber Reinforced ◽  
Surface Distress ◽  
Marshall Stability

Engineers are constantly trying to improve the performance of the flexible pavements. The main surface distress types which cause maintenance and disruption are rutting and fatigue cracking. For solving these problems, many studies have been carried out until now, ranged from changing gradation to adding polymers and fibers to asphalt mixture. In this study, polypropylene additive was selected as fiber additive because of low costing and having good correlation with asphalt pavement. Three type of polypropylene additive in the length 6, 12 and 19 mm were selected and used at five different percentages in the asphalt concrete mixture. Asphalt specimens were analysed by Marshall Analysis and finally tested by Marshall Stability apparatus. Adding polypropylene increased Marshall Stability (38%), and decreased Flow (39%). These results show that polypropylene can be helpful for increasing pavement life.

scholarly journals Behavior of high-modulus asphalt mixtures from the perspective of deformation characteristics (stiffness)

2021 ◽  
Author(s):  
Jan Valentin ◽  
Majda Belhaj ◽  
Pavla Vacková
Keyword(s):  
Asphalt Concrete ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Early Years ◽  
Technical Requirement ◽  
High Modulus ◽  
Technical Requirements ◽  
Different Temperatures ◽  
Pavement Structures ◽  
Technical Assessment

High modulus asphalt concrete (HMAC) presents a concept of an asphalt mixture with advanced performance which is suitable mainly for heavy loaded pavement structures. The mix concept was developed more than 25 years ago in France and became a standard in many countries. In the Czech Republic this type of asphalt mixtures is used since the early years of this millennium, when original technical requirements have been set. After almost 20 years a volunteer technical assessment started to validate whether the technical requirement set mainly for stiffness values and partly also for flexural strength or resistance to crack propagation are still up-to-date or if some reasonable modification is needed like was done several years ago in France when high modulus asphalt concrete of so called EME II or GP5 generation were brought to the practice. Based on this a study with focus on stiffness determination for more than 40 different HMACs was started. The stiffness was tested at different temperatures. At the same time virgin and aged asphalt mixtures were compared. Results from this study are presented by the paper.

Viscoelastic Properties of Field-Aged Cores

2013 ◽  
Vol 723 ◽  
pp. 551-556
Author(s):  
Ling Meng
Keyword(s):  
Asphalt Concrete ◽  
Viscoelastic Properties ◽  
Hot Mix Asphalt ◽  
Asphalt Mixture ◽  
Warm Mix Asphalt ◽  
Tension Test ◽  
Asphalt Mixtures ◽  
Direct Tension ◽  
Direct Tension Test ◽  
Aged Asphalt

Nowadays, engineers begin to pay more attention on field-aged asphalt concrete cores because they have more reality than the lab-made cores and the results can tell what happened to the pavement. However, it is not accurate to estimate the full asphalt mixture because as usual the pavement engineers can only extract the binder from it, not the mixture. Now there is a newly developed way to analysis the data more accurately using the Direct Tension Test. Because the field aged asphalt mixtures are not aged uniformly with the pavement depth because of various reasons, there is a modulus gradient going through deeply through the asphalt layer and usually the stiffest layer is the surface because normally the surface is more aged. A method has been developed to analysis this behavior. Tests are both taken on field cores which are Hot Mix Asphalt (HMA) and Warm Mix Asphalt (WMA). During the research, the authors found that it is both applicable for all the field cores. More information about this method and tests are detailed in the following paragraphs.

Research on Asphalt Mixture Force Chains Identification Criteria Based on Computational Granular Mechanics

2020 ◽  
Author(s):  
Guoqiang Liu ◽  
Yuanyuan Pan ◽  
Yongli Zhao ◽  
Jian Zhou ◽  
Jing Li ◽  
...  
Keyword(s):  
Contact Force ◽  
Asphalt Concrete ◽  
Asphalt Mixture ◽  
Threshold Value ◽  
Asphalt Mixtures ◽  
Force Chains ◽  
Particle Flow Code ◽  
External Loading ◽  
The Difference ◽  
Skeleton Structure

The difference of force chains can be used to evaluate asphalt mixture skeleton structure. In this study, different asphalt mixture discrete element method (DEM) models were established via the two dimensional particle flow code (PFC2D) software to analyze force chains identification criteria. And then, the force chains lengths of different asphalt mixtures were quantified preliminarily. Results indicate that the average contact force <F> need to be set as the contact force threshold value. 45o is recommended as the angle threshold value. For asphalt mixtures, less than 50% aggregate content is involved in transferring external loading. Whether the aggregate is located on the force chains should be regarded as an important criterion to judge whether the aggregate is involved in the asphalt mixture skeleton composition. Although dense-graded asphalt concrete (AC) will generate many force chains, most of them are short length force chains that are not conducive to transferring loading.

High Temperature Stability of Modified Asphalt Concrete

2013 ◽  
Vol 438-439 ◽  
pp. 391-394 ◽  
Author(s):  
Yuan Zhao Chen ◽  
Zhen Xia Li
Keyword(s):  
High Temperature ◽  
Asphalt Concrete ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Temperature Stability ◽  
Asphalt Mixtures ◽  
High Temperature Stability ◽  
Weak Stability ◽  
Modified Asphalt ◽  
Longitudinal Slope

According to high temperature weak stability of common asphalt mixture, rutting tests of diatomite modified asphalt mixture, modified lake asphalt mixture, modified rock asphalt mixture and common asphalt mixture are carried out. Changes of dynamic stability for common asphalt mixture compared with modified asphalt mixtures are comparatively analysed. The results show that compared with common asphalt mixture, rutting resistances of diatomite modified asphalt mixture, modified lake asphalt mixture and modified rock asphalt mixture are greatly improved. It is proposed that those kinds of modified asphalt mixture are adopted in asphalt pavement of large longitudinal slope section.

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