摘要: |
This report presents the research undertaken within two areas of study of thin asphalt concrete (AC) overlays to rehabilitate continuously reinforced concrete pavements (CRCP). The first one is the development of a decision tree for the project selection of a rehabilitation of this kind. The second area is the testing of tack coats and AC mixtures for its use in AC overlays. Within the first area, several decision criteria, based on the functional and structural characteristics of the existing pavement, were developed to evaluate the technical suitability of AC overlays on CRCP. These criteria are, namely, a profile criterion, based on the remaining life concept and on the formulation of a dynamic load factor; a condition survey criterion, which utilizes a pavement distress index and the rate of failures per mile per year; and a deflection criterion, which evaluates the hypothetical contribution of an AC overlay based upon deflection measurements performed on the existing structure. The second part of the study investigated the interface shear strength of tack coats used for bonding AC and portland cement concrete pavement (PCCP), and the rutting resistance of asphalt mixtures for use as overlays on CRCP. A shear test was developed for the tack coats experiment, and it was found that mixes with finer gradations appear to improve the shear strengths of tack coat interfaces. Based on the results of the rutting resistance tests, it is recommended to use Superpave, CMHB, and Type C mixes for AC overlays on CRCP, and to avoid using siliceous river gravel aggregates in these mixes, because of its inferior performance. / NOTE: Technical rept. (9/2002-8/2003). / Supplementary Notes: See also PB2005-109389, PB2005-104886, and PB2007-110192. Sponsored by Texas Dept. of Transportation, Austin. Research and Technology Implementation Office. and Federal Highway Administration, Austin, TX. Texas Div. / Availability Note: Order this product from NTIS by: phone at 1-800-553-NTIS (U.S. customers); (703)605-6000 (other countries); fax at (703)605-6900; and email at orders@ntis.gov. NTIS is located at 5285 Port Royal Road, Springfield, VA, 22161, USA. |