Estimation of AASHTO Layer Coefficients for Bituminous Mixes

Estimation of AASHTO Layer Coefficients for Bituminous Mixes
Author: Michael Eugene Ayers
Publisher:
Total Pages: 216
Release: 1993
Genre: Asphalt concrete
ISBN:

The resilient modulus test procedure, as specified by the Strategic Highway Research Program (SHRP) P07 protocol, is used to evaluate Oklahoma Department of Transportation (ODOT) types A, B, and G asphalt concrete mixes. Structural layer coefficients are estimated based on the resilient modulus test results. A full face dynamic compaction apparatus was designed and constructed to allow fabrication of large aggregate asphalt concrete samples. The dynamic compaction apparatus is compared with the Marshall and gyratory compaction techniques. A comparison of 4-, 6-, and 8-in. (10.2-, 15.2-, and 20.4-cm) specimens is presented as is a thorough statistical analysis of the material and test variability.

Estimation of Layer Coefficients for Flexible Pavement Design and Development of a Practical and Rational Mix-design

Estimation of Layer Coefficients for Flexible Pavement Design and Development of a Practical and Rational Mix-design
Author:
Publisher:
Total Pages: 58
Release: 1994
Genre:
ISBN: 9781895102512

Pavement layer coefficients had been identified as essential parameters to use the 1986/1993 AASHTO Guide for Design of Pavement Structures (AASHTO guide) in Rhode Island. Layer coefficients of granular subbase materials were estimated using the direct method recommended by AASHTO Guide. Resilient moduli were determined using a pneumatic testing system. Coefficients based on resilient moduli ranged from 0.08 to 0.14, and the average was 0.12 for eight subbase samples in Rhode Island. The pneumatic testing system was also used to determine resilient moduli of bound layeres. Based on results of a series of testing, layer coefficients were estimated using moduli at the loading magnitude of 20% of tensile strength and loading frequency of 0.5Hz. Recommended coefficients for wearing course (Class I-1), modified binder, and modified asphalt base were 0.40, 0.42, and 0.43, respectively. If all asphalt bound layers will be analyzed as one layer, the coefficient of 0.41 was recommended for pavement design and analysis in Rhode Island. Field study including FWD testing was performed to verify laboratory test results. Laboratory determined moduli were compared with backcalculated moduli based on FWD deflection data. Generally, FWD moduli are consistently higher than laboratory moduli with a wide range of variability. For the covering abstract of this conference, see IRRD number 863140.

Rational Determination of Pavement Layer Structural Coefficients

Rational Determination of Pavement Layer Structural Coefficients
Author: Eddie Y. J. Chou
Publisher:
Total Pages: 98
Release: 1999
Genre: Asphalt concrete
ISBN:

Seven flexible pavements ranging from interstate to state route are selected. Three different approaches are employed. The first two use the resilient modulus of the material to estimate its structural coefficient. In the first approach, cored specimens are obtained from each of the pavement sections and the resilient moduli of in-service 301 and 446/448 materials are determined in the laboratory. The second approach backcalculates layer elastic modulus from measured pavement deflection. The third approach determines the structural coefficient from the AASHTO flexible pavement performance equation based on traffic and serviceability history data.

AASHTO Guide for Design of Pavement Structures, 1993

AASHTO Guide for Design of Pavement Structures, 1993
Author: American Association of State Highway and Transportation Officials
Publisher: AASHTO
Total Pages: 622
Release: 1993
Genre: Pavements
ISBN: 1560510552

Design related project level pavement management - Economic evaluation of alternative pavement design strategies - Reliability / - Pavement design procedures for new construction or reconstruction : Design requirements - Highway pavement structural design - Low-volume road design / - Pavement design procedures for rehabilitation of existing pavements : Rehabilitation concepts - Guides for field data collection - Rehabilitation methods other than overlay - Rehabilitation methods with overlays / - Mechanistic-empirical design procedures.

Evaluation of Procedure to Assign Structural Layer Coefficients for Use in Flexible Pavement Design

Evaluation of Procedure to Assign Structural Layer Coefficients for Use in Flexible Pavement Design
Author: Harold L. Von Quintus
Publisher:
Total Pages: 38
Release: 2007
Genre: Pavements, Asphalt
ISBN:

The Kansas Department of Transportation (DOT) uses the 1993 DARWin version of the 1986 AASHTO Guide to design flexible pavements and rehabilitation strategies of flexible pavements. One of the inputs needed for the flexible pavement design procedure is the structural layer coefficient for each pavement layer. The Kansas DOT procedure to assign structural layer coefficients was developed years ago and based on an analysis of flexible pavement performance data and layer properties. It has been recently suggested that the Kansas DOT increase the structural layer coefficients because of changes in material and construction specifications. Different procedures can be used to estimate the structural layer coefficients for flexible pavement design. As part of the study entitled Determination of the Appropriate Use of Pavement Surface History in the KDOT Life-Cycle Cost Analysis Process an evaluation of the procedure that Kansas DOT uses to assign structural layer coefficients to different pavement materials was completed. This report provides the results of that evaluation.