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原文传递 Development and Evaluation of Test Methods to Evaluate Water Damage and Effectiveness of Antistripping Agents.

题名：	Development and Evaluation of Test Methods to Evaluate Water Damage and Effectiveness of Antistripping Agents.
作者：	BIRGISSON, B.; MASAD, E.; ROQUE, R.; TIA, M.
关键词：	Hot-mix-paving-mixtures; Test-methods; Moisture-; Pavement-damage.;Literature-review; Performance-evaluation; Nondestructive-testing; Fracture-mechanics; Permeability-; Speed-; Aggregates-; Binders-; Damage-; Water-.
摘要：	Fine aggregate for asphalt mixtures often contain crystalline quartz particles that will not retain asphalt coatings and that will strip readily in the presence of water. This condition can reduce the durability of asphalt pavements resulting in raveling and/or cracking. Liquid anti-strip agents are often added to asphalt cements to promote adhesion and prevent stripping of the asphalt film from the aggregate. Lime treatment of aggregate prior to production of hot-mix asphalt is considered as an alternative to liquid anti-stripping agents in the prevention of stripping. Although the term 'stripping' is generally used to define any form of water damage, the mechanisms that promote distress in asphalt pavements are various. None of the mechanisms proposed in the literature have been proven by connecting theoretical considerations to observed field behavior. Rather, these mechanisms are hypothesized based on field observation and limited basic laboratory characterization. There are currently no performance-based methods available for evaluating moisture damage in mixtures that have been widely accepted by state agencies. The methods used to evaluate moisture susceptibility of mixtures tend to be either qualitative techniques, e.g., the boil test, or crude quantitative techniques that may neither include the appropriate mechanism of moisture damage nor the appropriate framework for analyzing the effects of moisture damage on mixtures. There is a clear need to identify the most likely mechanism(s) of moisture damage in pavements. The identification of the key mechanism(s) of moisture damage will allow for the development of an appropriate laboratory-based conditioning system, along with the development of a robust performance-based framework for the evaluation of mixture moisture damage susceptibility. These new conditioning and evaluation methods should be capable of quantifying the effectiveness of liquid anti-stripping agents, lime, and/or other additives considered to enhance the adhesion of asphalt binders to aggregate surfaces. The primary objective of the proposed research is to define the effect that interacting mixture and mineralogical properties have on moisture damage in mixtures. Specific objectives include the following: Identification of key mechanism(s) of moisture damage in pavements; Development of test equipment and procedures for evaluating moisture damage in mixtures; Determination of permeability limits to minimize moisture damage, as well as aggregate mineralogical properties that affect moisture damage; and Development of a new conditioning, which is based on the most likely mechanism(s) of water damage.
报告类型：	科技报告