Repeatability of the Resilient Modulus Test Procedure

Repeatability of the Resilient Modulus Test Procedure
Author: RL. Boudreau
Publisher:
Total Pages: 11
Release: 2003
Genre: Pavements, Asphalt
ISBN:

Through the work of the Strategic Highway Research Program (SHRP, 1987-1992) and the Federal Highway Administration (FHWA, 1992-present), the government has provided financial and technical assistance to develop and improve a laboratory test method to determine the resilient modulus properties of unbound materials. Although the work -- part of the Long Term Pavement Performance (LTPP) study -- has led towards the adoption of test procedure T307-99 in the current release of the American Association of State Highway and Transportation Officials (AASHTO) Tests, many skeptics insist that the method does not lend itself towards repeatable, reproducible test results.

Resilient Modulus Testing for Pavement Components

Resilient Modulus Testing for Pavement Components
Author: Mary Stroup-Gardiner
Publisher: ASTM International
Total Pages: 274
Release: 2003
Genre: Pavements
ISBN: 0803134614

"Resilient modulus indicates the stiffness of a soil under controlled confinement conditions and repeated loading. The test is intended to simulate the stress conditions that occur in the base and subgrade of a pavement system. Resilient modulus has been adopted by the U.S. federal highway administration as the primary performance parameter for pavement design. We thank those who prepared these papers, the reviewers who provided anonymous peer reviews, and those who participated in the symposium. We hope this STP encourages more work to improve the testing standard and the value of the Resilient Modulus test."

A Simple Method for Determining Modulus of Base and Subgrade Materials

A Simple Method for Determining Modulus of Base and Subgrade Materials
Author: D. Yuan
Publisher:
Total Pages: 13
Release: 2003
Genre: Base
ISBN:

The resilient modulus test is commonly used to determine the modulus of base or subgrade materials as well as to establish their nonlinear behavior. Since the resilient modulus test is time consuming, the number of tests performed for a given project is limited. For day-to-day operation of highway agencies, a more rapid test method is needed. The stress wave (or seismic) method is being considered in Texas for this purpose. Seismic methods of testing can rapidly and nondestructively provide fundamentally correct moduli at known states of stress. Unlike the resilient modulus test, comparative field testing methods are available for seismic methods that can provide similar results under similar conditions. This paper describes the seismic test procedure and its relationship to the resilient modulus test results. Also discussed are the repeatability and reproducibility of the results as a function of operator experience, type of soil, and preparation method.

Effect of Strain Measurements on Resilient Modulus of Sands

Effect of Strain Measurements on Resilient Modulus of Sands
Author: P. Alavilli
Publisher:
Total Pages: 20
Release: 1994
Genre: Dynamic testing
ISBN:

The 1986 AASHTO Guide for Design of Pavement Structures and several other mechanistic design approaches use resilient modulus (Mr) as a fundamental property to characterize highway materials. Precise measurement of resilient deformations during laboratory repeated load tests is the key element in obtaining proper and accurate resilient modulus values. An extensive experimental program was initiated at Louisiana Transportation Research Center to develop a testing and interpretation procedure for estimating the resilient modulus of Louisiana soils. This paper presents the results conducted on a locally available blasting sand. A statistically designed experimental factorial was used to evaluate the repeatability and the influence of measurement systems as well as AASHTO procedures. Two types of in-cell measurement systems, one relative to top and bottom platens and the other within the mid-third of the specimen length were used. Also, two different test procedures, AASHTO T-292 and T-294 were examined. Results of this study indicate that the test results are repeatable and the measurement systems and AASHTO procedures do influence the resilient modulus results. Correlations between Mr and bulk stress were also developed using ? model.

Resilient Modulus Testing of Unbound Materials

Resilient Modulus Testing of Unbound Materials
Author: PN. Schmalzer
Publisher:
Total Pages: 15
Release: 2003
Genre: Guidelines
ISBN:

Resilient modulus is a key data element for characterizing unbound pavement materials within the LTPP program. Although the test has been around for nearly three decades, its implementation within the program has been a challenge. A suitable test protocol was not available when the program began in 1987. It was incorrectly assumed in the early years that equipment manufactured for the test would work as intended. It was also incorrectly assumed that properly operating equipment and knowledgeable personnel imply good data. This paper has been prepared to share LTPP's experience over the past 14 years in achieving repeatable, high-quality resilient modulus data. Specific issues addressed in the paper include the test protocol, laboratory startup and quality control procedures, quality control and quality assurance processes, and comprehensive guidelines contained in an easy-to-use, interactive CD-ROM.

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.