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Title: EVALUATION OF LOW-TEMPERATURE PAVEMENT CRACKING ON ELK COUNTY RESEARCH PROJECT
Accession Number: 00334210
Record Type: Component
Availability: Find a library where document is available Abstract: The Elk County Research Project in Pennsylvania consists of six test pavements constructed in September 1976 by using AC-20 asphalt cements from different sources. Two test pavements developed extensive low-temperature non-load-associated cracking during the first severe winter. After 2.5 years in service and two more severe winters, the remaining four test pavements do not exhibit any significant cracking. Periodic performance evaluation of these pavements has been conducted. Cracking of the two test pavements was attributed to high stiffness moduli of asphalt cement and asphaltic concrete, determined by indirect nomograph methods. It was felt that the stiffness moduli should also be determined by direct measurements on actual pavement cores. Split tensile tests were conducted at four below-freezing temperatures at a deformation rate of 1.27 mm/s (0.05 in/min) to determine such basic mix properties as stiffness modulus, tensile strength, and tensile strain at failure. Stiffness moduli of the aged pavements were also determined by the indirect Heukelom and McLeod methods. The data from the tensile test indicate that tensile strength or tensile strain at failure, considered independently, does not explain the low-temperature cracking phenomenon on this project. Both direct measurements and indirect methods show that the stiffness modulus of the asphaltic concrete is a better indicator of potential low-temperature cracking. Stiffness moduli determined from the tensile test were generally found to be lower than those obtained by the two indirect methods. A maximum permissible stiffness modulus of 26.9 MPa (3900 lbf/sq in) for original asphalt cement (at minimum pavement design temperature and 20,000s loading time) has been selected to develop AC-20 asphalt cement specifications for the cold regions of Pennsylvania. (Author)
Supplemental Notes: Publication of this paper sponsored by Task Force on Low-Temperature Properties of Asphalt.
Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences.
Copyright © National Academy of Sciences. All rights reserved
Monograph Title: Monograph Accession #: 01411595
Authors: Kandhal, Prithvi SDiscussers: Schweyer, H E; Ruth, B E; Potts, C F
Pagination: pp 39-50
Publication Date: 1980
Serial: Media Type: Print
Features: Figures
(15)
; References; Tables
(10)
TRT Terms: Uncontrolled Terms: Old TRIS Terms: Subject Areas: Design; Highways; Materials; Pavements; I22: Design of Pavements, Railways and Guideways; I23: Properties of Road Surfaces; I31: Bituminous Binders and Materials
Files: TRIS, TRB
Created Date: Sep 16 1981 12:00AM
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