Mixture-property-independent asphalt film thickness model

2019 ◽  
Vol 19 ◽  
pp. 482-486 ◽  
Author(s):  
Ghazi G. Al-Khateeb ◽  
Aroon Shenoy
Keyword(s):  
Film Thickness ◽  
Asphalt Film

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

Design Method of Asphalt Treated Base Asphalt Content Based on Cohesive Strength

2013 ◽  
Vol 361-363 ◽  
pp. 1794-1799
Author(s):  
Yi Zhang ◽  
Chong Wei Huang ◽  
Wei Jie Liu ◽  
Yi Feng Xu
Keyword(s):  
Tensile Strength ◽  
Film Thickness ◽  
Compression Strength ◽  
Design Method ◽  
Cohesive Strength ◽  
Calculation Methods ◽  
Tensile Performance ◽  
Calculation Results ◽  
Asphalt Content ◽  
Asphalt Film

Combining with compression strength and tensile strength, the cohesive strength method is applied to determine the asphalt content (by weight of aggregate) of asphalt treated base (ATB) for the purpose meeting ATB tensile performance. The results are compared with those of Marshall Method. Two calculation methods of asphalt film thickness are applied to calculate the thickness of asphalt film. The calculation results show that cohesive strength method force the admixture to attain the better thickness of asphalt film, and the spectrum of film thickness is between about 6.5μm ~9.0μm.

Effect of Asphalt Film Thickness on Short- and Long-Term Aging of Asphalt Paving Mixtures

1996 ◽  
Vol 1535 (1) ◽  
pp. 83-90 ◽  
Author(s):  
Prithvi S. Kandhal ◽  
Sanjoy Chakraborty
Keyword(s):  
Film Thickness ◽  
Asphalt Binder ◽  
Accelerated Aging ◽  
Asphalt Cement ◽  
Aged Asphalt ◽  
Short And Long Term ◽  
Asphalt Paving ◽  
The Relationship ◽  
Asphalt Film

It is generally believed that an asphalt paving mixture should have an adequate asphalt film thickness around the aggregate particles to ensure reasonable durability (resistance to aging) of the mixture. The minimum asphalt film thickness generally recommended ranges from 6 to 8 μm. However, no significant background research data are available in the literature to support these recommended minimum asphalt film thicknesses. Some states specify minimum asphalt film thickness for mix designs. This study was undertaken to quantify the relationship between various asphalt film thicknesses and the aging characteristics of the asphalt paving mix so that an optimum film thickness desirable for satisfactory mix durability could be established. Mixes prepared with asphalt binder film thickness ranging from about 4 to 13 μm were subjected to accelerated aging using Strategic Highway Research Program (SHRP) procedures to simulate both short- and long-term aging. Both the aggregate (RD) and the asphalt cement (AAM-1) used in this study were obtained from the SHRP Materials Reference Library. The aged, compacted mix was tested for tensile strength, tensile strain at failure, and resilient modulus. The aged asphalt cement was recovered and tested for penetration, viscosity, complex modulus, and phase angle. Aging indexes were obtained from these tests, and the relationship between film thickness and the aged mix/aged asphalt cement properties were determined using regression analysis. For the particular aggregate/asphalt cement combination used in this study, it was found that accelerated aging would occur if the asphalt binder film thickness was less than 9 to 10 μm in an asphalt paving mixture compacted to 8 percent air void content.

Method to Determine Asphalt Film Thickness Based on Actual Measurement

2013 ◽  
Vol 779-780 ◽  
pp. 140-143
Author(s):  
De Bao Lv ◽  
Xiao Ming Huang ◽  
Chang Lu Guan
Keyword(s):  
Film Thickness ◽  
Surface Area ◽  
New Method ◽  
Mineral Filler ◽  
Actual Measurement ◽  
Asphalt Film

Based on the data got from actual measurement of mineral filler and aggregate surface area, this paper is going to present a new method, which is different from conventional approaches, to help to determine aggregate surface area. A formula that can be used to calculate aggregate surface area will be obtained. Currently, many methods are available to calculate asphalt film thickness. These methods are not perfect and deserve a new survey. Therefore, by referring to and analyzing those existing methods, this paper will put forward a revised, updated and instructive calculating formula to guarantee the accuracy of calculation.

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.

Effect of Asphalt Film Thickness on the Performance of ATB Mixture

2015 ◽  
Vol 744-746 ◽  
pp. 1378-1381
Author(s):  
Zhi Feng Zhang
Keyword(s):  
Film Thickness ◽  
Design Method ◽  
Heavy Traffic ◽  
Related Research ◽  
Technical Indicators ◽  
Reasonable Range ◽  
Different Thickness ◽  
Comprehensive Property ◽  
Related Design ◽  
Asphalt Film

The rapidly development of highway needs the related research. For the lack of design method of mixture asphalt which based on performance and component, the related design method is needed urgently. This can be very important to the heavy traffic highway in construction in our country. This paper analyses the influence on the performance of ATB mixture in the view of asphalt film thickness. We consider the change law of the performance of ATB mixture in different thickness of asphalt film, and the various technical indicators to determine a reasonable range of thickness of asphalt film and provide a reference for the design of mixture asphalt.Key word: asphalt film thickness, bituminous stabilized macadam, comprehensive property

Critical Review of Voids in Mineral Aggregate Requirements in Superpave

1998 ◽  
Vol 1609 (1) ◽  
pp. 21-27 ◽  
Author(s):  
Prithvi S. Kandhal ◽  
Kee Y. Foo ◽  
Rajib B. Mallick
Keyword(s):  
Film Thickness ◽  
Mix Design ◽  
Rational Approach ◽  
Asphalt Mixes ◽  
Mineral Aggregate ◽  
Superpave Gyratory Compactor ◽  
Asphalt Mix ◽  
Compactive Effort ◽  
Asphalt Content ◽  
Asphalt Film

Reports of increased difficulties in meeting the minimum voids in mineral aggregate (VMA) requirements have surfaced with the recent use of Superpave volumetric mix design. The low VMA of Superpave mixes generally can be contributed to the increased compactive effort by the Superpave gyratory compactor. This has led to the increased use of coarser asphalt mixes (gradations near the lower control points). However, the minimum VMA requirements in Superpave volumetric mix design for these coarse mixes are the same as those developed for the dense mixes designed by the Marshall method. Literature review has indicated that the rationale behind the minimum VMA requirement was to incorporate at least a minimum permissible asphalt content into the mix to ensure its durability. Studies have shown that asphalt mix durability is directly related to asphalt film thickness. Therefore, the minimum VMA should be based on the minimum desirable asphalt film thickness instead of on a minimum asphalt content because the latter will be different for mixes with different gradations. Mixes with coarse gradation (and, therefore, a low surface area) have difficulty meeting the minimum VMA requirement based on minimum asphalt content despite thick asphalt films. A rational approach based on a minimum asphalt film thickness has been proposed and validated. The film thickness approach represents a more direct, equitable, and appropriate method of ensuring asphalt mix durability, and it encompasses various mix gradations.

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