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

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.

Investigation of Tender Zone in Compaction of Coarse-Graded Superpave® Hot-Mix Asphalt Mixtures

2003 ◽  
Vol 1861 (1) ◽  
pp. 29-36 ◽  
Author(s):  
M. Shane Buchanan ◽  
L. Allen Cooley
Keyword(s):  
Film Thickness ◽  
Steam Distillation ◽  
Hot Mix Asphalt ◽  
Asphalt Binder ◽  
Asphalt Mixtures ◽  
Laboratory Evaluation ◽  
Temperature Differential ◽  
Before And After ◽  
Field Compaction ◽  
Possible Cause

Tender hot-mix asphalt mixtures have been observed and experienced by paving contractors for many years. However, during the field compaction of coarse-graded Superpave® mixes, a "tender zone," not a true tender mix, is sometimes experienced. The tender zone is a range of mix compaction temperatures during which the mixture exhibits instability during roller action. Many possible causes of the tender zone have been presented, including differences in laboratory and production absorption, mix moisture, a low dust-to-asphalt ratio, increased asphalt binder film thickness, and a temperature differential with the lift. A study was conducted to document and evaluate field mixtures exhibiting the tender zone to determine the possible cause(s) of its occurrence. Documentation included mix-, production-, and construction-related items. Laboratory evaluation consisted of mixture gradation and volumetric testing along with Superpave asphalt binder testing with the project asphalt binder before and after steam distillation. Project results failed to clearly identify one particular reason for the occurrence of the tender zone. However, it is believed that the tender zone was a result of field absorption being less than the design absorption and increased asphalt binder film thickness acting in conjunction with an inherent temperature differential within the lift.

Use of a Hot-Mix Asphalt Plant to Produce a Cold Central Plant Recycled Mix: Production Method and Performance

2021 ◽  
pp. 036119812110179
Author(s):  
Benjamin F. Bowers ◽  
R. Buzz Powell
Keyword(s):  
Test Section ◽  
Hot Mix Asphalt ◽  
Asphalt Mixture ◽  
Production Method ◽  
Asphalt Mixtures ◽  
Central Plant ◽  
Truck Loading ◽  
Control Section ◽  
Heavy Truck ◽  
And Performance

Cold central plant recycling (CCPR) of asphalt mixtures continues to grow in interest among agencies and asphalt mixture suppliers. However, one implementation challenge has been the need to invest in new equipment to produce the mixture. In 2015, the National Center for Asphalt Technology (NCAT) worked with a local contractor to produce a CCPR mixture through a standard hot-mix asphalt (HMA) plant. The mix was then placed in a test section on the NCAT Pavement Test Track with a highly modified dense graded HMA overlay. The process used to produce the mixture in the HMA plant is outlined along with the performance of the mixture after heavy truck loading in comparison with a control section with a highly modified dense graded hot-mix asphalt in lieu of CCPR. After 17 million equivalent single axle loads the test section containing the CCPR mixture is performing as well as the control section. This shows that CCPR can be successfully produced using an HMA plant, which may encourage mix suppliers and agencies to conduct trial projects with CCPR, implement CCPR into standard practice, and further justify new CCPR equipment investments.

scholarly journals A GPR-Based Pavement Density Profiler: Operating Principles and Applications

2021 ◽  
Vol 13 (13) ◽  
pp. 2613
Author(s):  
Nectaria Diamanti ◽  
A. Peter Annan ◽  
Steven R. Jackson ◽  
Dylan Klazinga
Keyword(s):  
Asphalt Pavement ◽  
Wave Impedance ◽  
Asphalt Mixtures ◽  
Void Content ◽  
Air Voids ◽  
New Instrument ◽  
Pavement Engineering ◽  
And Performance ◽  
Air Void ◽  
Air Void Content

Density is one of the most important parameters in the construction of asphalt mixtures and pavement engineering. When a mixture is properly designed and compacted, it will contain enough air voids to prevent plastic deformation but will have low enough air void content to prevent water ingress and moisture damage. By mapping asphalt pavement density, areas with air void content outside of the acceptable range can be identified to predict its future life and performance. We describe a new instrument, the pavement density profiler (PDP) that has evolved from many years of making measurements of asphalt pavement properties. This instrument measures the electromagnetic (EM) wave impedance to infer the asphalt pavement density (or air void content) locally and over profiles.

scholarly journals Volumetric Analysis and Performance of Hot Mix Asphalt with Variable Rap Content

2017 ◽  
Vol 103 ◽  
pp. 09004 ◽  
Author(s):  
Ahmad Kamil Arshad ◽  
Masyita Mohammad ◽  
Ekarizan Shaffie ◽  
Wardati Hashim ◽  
A. G. Abdul Halim
Keyword(s):  
Hot Mix Asphalt ◽  
Volumetric Analysis ◽  
And Performance

scholarly journals Evaluations of Nano-Sized Hydrated Lime on the Moisture Susceptibility of Hot Mix Asphalt Mixtures

2012 ◽  
Vol 174-177 ◽  
pp. 82-90 ◽  
Author(s):  
Ju Nan Shen ◽  
Zhao Xing Xie ◽  
Fei Peng Xiao ◽  
Wen Zhong Fan
Keyword(s):  
Tensile Strength ◽  
Experimental Design ◽  
Hot Mix Asphalt ◽  
Hydrated Lime ◽  
Asphalt Mixtures ◽  
Indirect Tensile Strength ◽  
Moisture Resistance ◽  
Strength Ratio ◽  
Moisture Susceptibility ◽  
Indirect Tensile

The objective of this study was to evaluate the effect of nano-sized hydrated lime on the moisture susceptibility of the hot mix asphalt (HMA) mixtures in terms of three methodologies to introduce into the mixtures. The experimental design for this study included the utilizations of one binder source (PG 64-22), three aggregate sources and three different methods introducing the lime. A total of 12 types of HMA mixtures and 72 specimens were fabricated and tested in this study. The performed properties include indirect tensile strength (ITS), tensile strength ratio (TSR), flow, and toughness. The results indicated that the nano-sized lime exhibits better moisture resistance. Introducing process of the nano-sized lime will produce difference in moisture susceptibility.

Implementing the Mechanistic–Empirical Design Guide Procedure for a Hot-Mix Asphalt–Rehabilitated Pavement in Indiana

2005 ◽  
Vol 1919 (1) ◽  
pp. 121-133 ◽  
Author(s):  
Khaled A. Galal ◽  
Ghassan R. Chehab
Keyword(s):  
Hot Mix Asphalt ◽  
Pavement Design ◽  
Design Parameters ◽  
Design Procedures ◽  
Design Concepts ◽  
Asphalt Overlay ◽  
Design Guide ◽  
Strategic Goals ◽  
And Performance

One of the Indiana Department of Transportation's (INDOT's) strategic goals is to improve its pavement design procedures. This goal can be accomplished by fully implementing the 2002 mechanistic–empirical (M-E) pavement design guide (M-E PDG) once it is approved by AASHTO. The release of the M-E PDG software has provided a unique opportunity for INDOT engineers to evaluate, calibrate, and validate the new M-E design process. A continuously reinforced concrete pavement on I-65 was rubblized and overlaid with a 13–in.-thick hot-mix asphalt overlay in 1994. The availability of the structural design, material properties, and climatic and traffic conditions, in addition to the availability of performance data, provided a unique opportunity for comparing the predicted performance of this section using the M-E procedure with the in situ performance; calibration efforts were conducted subsequently. The 1993 design of this pavement section was compared with the 2002 M-E design, and performance was predicted with the same design inputs. In addition, design levels and inputs were varied to achieve the following: ( a) assess the functionality of the M-E PDG software and the feasibility of applying M-E design concepts for structural pavement design of Indiana roadways, ( b) determine the sensitivity of the design parameters and the input levels most critical to the M-E PDG predicted distresses and their impact on the implementation strategy that would be recommended to INDOT, and ( c) evaluate the rubblization technique that was implemented on the I-65 pavement section.

Sign in / Sign up

Export Citation Format

Share Document