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原文传递 High-Performance Flexible Bases, Project Summary Report.

题名：	High-Performance Flexible Bases, Project Summary Report.
作者：	scullion, s. harris, j. p. sebesta, s. nazarian, s.
关键词：	moisture damage, rock properties, asphalt concretes, bituminous concretes, binders, hot mix paving mixtures, quality control
摘要：	Traditional Texas flexible bases, specified under Item 247, perform very well as long as they are kept dry. However, in documented forensic studies rapid and sudden failures have occurred when water enters these moisture-susceptible bases. As part of Project 0-4358, forensic investigations identified the cause of premature failure on two flexible pavement failures. In both cases water penetrated the base layer, and, as shown in Figure 1, the failures were rapid and severe. Project 0-4358 evaluated the concept of nonmoisture-susceptible high-performance bases. High-performance bases require tight control on the type and amount of fine material and the use of higher-strength rock. Bases with high fines contents can act like a sponge and soak up available moisture resulting in a loss of strength. A literature search found that of the states represented by the 12 agencies surveyed, Texas was the only state that does not regulate the amount of fines (minus no 200 sieve) in its bases. One finding of this project indicated that fines contents of 5 to 10 percent appear to be optimum for typical Texas material, whereas it is not uncommon to find current bases with more than 20 percent fines. / NOTE: Summary rept. / Supplementary Notes: See also PB2006-109714, PB2007-103749, and PB2008-107641. 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.
总页数：	u0814；4p
报告类型：	科技报告