Compaction Effects on Uniformity, Moisture Diffusion, and Mechanical Properties of Asphalt Pavements

Compaction Effects on Uniformity, Moisture Diffusion, and Mechanical Properties of Asphalt Pavements. (December 2008) Emad Abdel-Rahman Kassem, B.S., Zagazig University, Egypt; M.S., Texas A&M University Chair of Advisory Committee: Dr. Eyad Masad Field compaction of asphalt mixtures is an important process that influences performance of asphalt pavements; however there is very little effort devoted to evaluate the influence of compaction on the uniformity and properties of asphalt mixtures. The first part of this study evaluated relationships between different field compaction patterns and the uniformity of air void distribution in asphalt pavements. A number of projects with different asphalt mixture types were compacted, and cores were taken at different locations from these projects. The X-ray Computed Tomography (X-ray CT) system was used to capture the air void distributions in these cores. The analysis results have revealed that the uniformity of air void distribution is highly related to the compaction pattern and the sequence of different compaction equipment. More importantly, the efficiency of compaction (reducing air voids) at a point was found to be a function of the location of this point with respect to the compaction roller width. The results in this study supported the development of the “Compaction Index (CI),” which quantifies the degree of field compaction. The CI is a function of the number of passes at a point and the position of the point with respect to the compaction roller width. This index was found to correlate reasonably well with percent air voids in the pavement. The CI calculated from field compaction was also related to the slope of the compaction curve obtained from the Superpave gyratory compactor. This relationship offers the opportunity to predict field compactability based on laboratory measurements. The compaction of longitudinal joints was investigated, and recommendations were put forward to improve joint compaction. The air void distributions in gyratory specimens were related to the mixture mechanical properties measured using the Overlay and Hamburg tests. iv The second part of this study focused on studying the relationship between air void distribution and moisture diffusion. A laboratory test protocol was developed to measure the diffusion coefficient of asphalt mixtures. This important property has not measured before. The results revealed that the air void phase within the asphalt mixtures controls the rate of moisture diffusion. The measured diffusion coefficients correlated well with the percent and size of connected air voids. The measured diffusion coefficient is a necessary parameter in modeling moisture transport and predicting moisture damage in asphalt mixtures. The last part of this study investigated the resistance of asphalt mixtures with different percent air voids to moisture damage by using experimental methods and a fracture mechanics approach that accounts for fundamental material properties.

[1]  D. Little,et al.  Characterization of microdamage and healing of asphalt concrete mixtures , 2002 .

[2]  David E. Newcomb,et al.  CONCEPTS OF PERPETUAL PAVEMENTS , 2001 .

[3]  R. B. Montgomery.  VISCOSITY AND THERMAL CONDUCTIVITY OF AIR AND DIFFUSIVITY OF WATER VAPOR IN AIR , 1947 .

[4]  Naga Shashidhar,et al.  X-Ray Tomography of Asphalt Concrete , 1999 .

[5]  D. Fredlund,et al.  Soil Mechanics for Unsaturated Soils , 1993 .

[6]  E. Masad,et al.  Internal structure analysis of asphalt mixes to improve the simulation of Superpave gyratory compaction to field conditions , 2001 .

[7]  Ala R. Abbas,et al.  Nondestructive measurements of moisture transport in asphalt mixtures , 2007 .

[8]  Robert L. Lytton,et al.  Measurements of Moisture Suction and Diffusion Coefficient in Hot-Mix Asphalt and Their Relationships to Moisture Damage , 2006 .

[9]  Manfred N. Partl,et al.  Gyratory Compaction Analysis with Computer Tomography , 2003 .

[10]  Eyad Masad,et al.  Internal Structure Characterization of Asphalt Concrete Using Image Analysis , 1999 .

[11]  Nicole Kringos,et al.  Raveling of asphaltic mixes due to water damage : Computational identification of controlling parameters , 2005 .

[12]  Tom Scullion,et al.  Perpetual Pavements in Texas: The Fort Worth SH 114 Project in Wise County , 2007 .

[13]  Manfred N. Partl,et al.  Comparison of Laboratory Compaction Methods using X-ray Computer Tomography , 2007 .

[14]  Edith Arambula Mercado,et al.  Influence of fundamental material properties and air void structure on moisture damage of asphalt mixes , 2009 .

[15]  Eyad Masad,et al.  Comparing Superpave Gyratory Compactor Data to Field Cores , 2004 .

[16]  Charles D. Ghilani,et al.  Elementary Surveying: An Introduction to Geomatics , 2005 .

[17]  Robert L. Lytton,et al.  Characterization of HMA Moisture Damage Using Surface Energy and Fracture Properties (With Discussion) , 2006 .

[18]  Rifat Bulut,et al.  Indirect Measurement of Suction , 2008 .

[19]  Robert L. Lytton,et al.  System for the Evaluation of Moisture Damage Using Fundamental Material Properties , 2007 .

[20]  Nicole Kringos.  Simulation of Combined Mechanical-Moisture Induced Damage in Asphaltic Mixes , 2005 .

[21]  Thomas Harman,et al.  Quantifying Laboratory Compaction Effects on the Internal Structure of Asphalt Concrete , 1999 .

[22]  P. W. Mitchell.  The Structural Analysis of Footings on Expansive Soil , 1980 .

[23]  Tom Scullion.  PERPETUAL PAVEMENTS IN TEXAS: STATE OF THE PRACTICE , 2006 .

[24]  Irving Kett.  BULK SPECIFIC GRAVITY of COMPACTED BITUMINOUS MIXTURES USING SATURATED SURFACE-DRY SPECIMENS: Reference - ASTM Designation: D 2726 , 1998 .

[25]  Olga J. Pendleton,et al.  CORRELATION OF SELECTED LABORATORY COMPACTION METHODS WITH FIELD COMPACTION , 1994 .

[26]  Eyad Masad.  X-ray computed tomography of aggregates and asphalt mixes , 2004 .

[27]  Nicole Kringos,et al.  Three Dimensional Elasto-Visco-Plastic Finite Element Model for Combined Physical-Mechanical Moisture Induced Damage in Asphaltic Mixes , 2007 .

[28]  John T Harvey,et al.  Effects of laboratory asphalt concrete specimen preparation variables on fatigue and permanent deformation test results using strategic highway research program A-003A proposed testing equipment , 1993 .

[29]  C. Geankoplis.  Transport processes and unit operations , 1978 .

[30]  Fujie Zhou,et al.  Upgraded Overlay Tester and Its Application to Characterize Reflection Cracking Resistance of Asphalt Mixtures , 2003 .

[31]  Reynaldo Roque,et al.  Evaluation of Water Damage Using Hot Mix Asphalt Fracture Mechanics , 2003 .

[32]  Robert L. Lytton,et al.  Simple Method for Predicting Laboratory and Field Permeability of Hot-Mix Asphalt , 2006 .

[33]  G. Bolt,et al.  Thermodynamics of soil moisture. , 1960 .

[34]  Harold L Von Quintus,et al.  COMPARATIVE EVALUATION OF LABORATORY COMPACTION DEVICES BASED ON THEIR ABILITY TO PRODUCE MIXTURES WITH ENGINEERING PROPERTIES SIMILAR TO THOSE PRODUCED IN THE FIELD , 1989 .

[35]  Emad Kassem.  Measurements of moisture suction in hot mix asphalt mixes , 2006 .

[36]  C. Lakshmana Rao,et al.  Mechanics of air voids reduction of asphalt concrete using mixture theory , 2000 .

[37]  John T Harvey,et al.  EVALUATION OF LABORATORY PROCEDURES FOR COMAPCTING ASPHALT-AGGREGATE MIXTURES , 1991 .

[38]  Henderikus Lodewikus ter Huerne,et al.  Compaction of asphalt road pavements : using finite elements and critical state theory , 2004 .

[39]  Carl L Monismith,et al.  ANALYTICALLY BASED ASPHALT PAVEMENT DESIGN AND REHABILITATION: THEORY TO PRACTICE, 1962-1992 , 1992 .

[40]  R. Bulut,et al.  Free Energy of Water-Suction-in Filter Papers , 2005 .

[41]  Peter J. Bosscher,et al.  A Porous Elasto-Plastic Compaction Model for Asphalt Mixtures with Parameter Estimation Algorithm , 2003 .

[42]  S. Caro,et al.  Moisture susceptibility of asphalt mixtures, Part 1: mechanisms , 2008 .