INTRODUCTION This Thirty-Fourth Edition of Transportation Materials is published in two parts. Part 1 contains specifications for materials@ and Part 2 includes methods of testing and specifications for testing equipment. Part 1 contains 137 materials specifications and 54 Standard Practices@ of which most contain both English and Metric units of measure. Technical revisions were made in 28 of the standards since the Thirty-Third Edition@ 27 standards were reconfirmed@ 3 new standards were added@ 1 standard was discontinued@ and 4 standards were deleted. A number of specifications were included in this publication at the request of the AASHTO Subcommittee on Bridges and Structures. Many of these specifications agree with those of the American Society for Testing and Materials (ASTM). In all cases where the Association and ASTM standards are technically identical@ or substantially identical with some changes@ reference to the ASTM designation number is shown in the heading of the specification. In previous editions@ AASHTO has printed ASTM standards which have been adopted by AASHTO and given an AASHTO designation. This was done under a long-standing copyright arrangement between AASHTO and ASTM. Starting with the Thirty-First Edition@ AASHTO-approved ASTM standards are not printed. Instead@ the AASHTO specification includes the corresponding ASTM designation number and any AASHTO exception to the ASTM specification. A complete list of AASHTO specifications with corresponding ASTM standards is included following the Table of Contents. General jurisdiction over Association standards in this field rests with the AASHTO Highway Subcommittee on Materials@ which has members representing each of the 50 States@ the Commonwealth of Puerto Rico and the District of Columbia@ that constitute the Member Departments of the Association@ and the U.S. Department of Transportation. In addition@ the Subcommittee has representation from several of its Associate Members@ including the Massachusetts Metropolitan District Commission@ the New Jersey Turnpike Authority@ and the Port Authority of New York and New Jersey. Also represented on the Subcommittee are most of the Association's International Associate members@ including the Canadian Provinces of New Brunswick@ the Northwest Territories@ Nova Scotia@ Ontario@ and Saskatchewan. Beginning in 1993 with the Sixteenth Edition@ material specifications and test methods are published by AASHTO each year. Annual revisions are voted upon by the Association's 52 Member Departments prior to the publication of each new edition of this book@ and if approved by at least two-thirds of the Member Departments@ they are included in the edition as standards of the Association. Comments regarding these specifications are welcomed and should be addressed to the Executive Director of AASHTO@ 444 North Capitol Street@ N.W.@ Suite 249@ Washington@ D.C. 20001. AASHTO's Web site and internet address is http://transportation.org.