Stripping of Aggregates Due to Unfavorable Field Condition

Abstract

This paper presents a comprehensive investigation into the phenomenon of aggregate stripping in asphalt mixtures, a prevalent issue affecting the durability and performance of road pavements under unfavorable field conditions. Through a combination of literature review, laboratory experiments, and field observations, the study aims to identify the root causes of aggregate stripping, assess its detrimental effects on pavement performance, and propose effective mitigation strategies.

The literature review explores the various mechanisms leading to aggregate stripping, including moisture-induced damage, chemical interactions between aggregates and asphalt binder, and the impact of freeze-thaw cycles. Additionally, the review examines specific field conditions that contribute to stripping, such as suboptimal aggregate quality, inadequate binder-aggregate adhesion, and environmental factors like rainfall and temperature fluctuations.

Laboratory experiments involve the selection of representative aggregates and binders, with a focus on designing test specimens that simulate real-world conditions. Testing procedures include moisture susceptibility tests, binder-aggregate adhesion tests, and thermal cycling experiments. The resulting data analysis aims to quantify the extent of stripping effects and establish correlations between laboratory findings and field observations.

Field observations encompass case studies examining pavements experiencing aggregate stripping, identifying contributing factors in authentic scenarios. The performance assessment evaluates pavement distress due to stripping, emphasizing long-term effects on serviceability.

Mitigation strategies are proposed based on the study's findings. These include improved aggregate selection through quality control measures and the use of additives to enhance aggregate-binder adhesion. Enhanced mix design suggestions involve modifying asphalt binder properties and optimizing aggregate gradation. Construction practices, such as implementing best practices during pavement construction and ensuring proper compaction and curing procedures, are also explored.