FAILURE MODES AND REQUIRED PROPERTIES IN ASPHALT-AGGREGATE COLD MIX BASES

This interim report summarizes the first part of phase 1.1 of the research project. The report introduces the objectives, scope and basic approach of the research, and describes the analytical study and actual field survey. The study and analysis described include: 1) Identification and classification of different types of failure and distress frequently occurring in actual cold mix bases. 2) Analysis of the failure modes to identify factors that cause the various types of distress and the properties needed in the mixture (required properties). 3) Quantitative determination of a) the relative significance of a given required property as related to the performance of actual cold mix bases and b) the local frequency of occurrence of the given failure group in actual service performance of the base. The analysis was based on data collected from a) comprehensive and critical literature review, b) survey study of local country roads, c) field visits and interviews. A foundation thus has been established for identifying feasible test methods and relating them to the major required properties which affect the behavior of actual cold mixes. /FHWA/