Flexural Fatigue Characteristics of a Stabilized Base Course Containing Recycled Aggregate and Waste HDPE Strips

摘要

An experimental research was conducted to study the flexural fatigue behavior of a stabilized base course containing recycled aggregate, American Society for Testing and Materials (ASTM) Cass C fly ash, Type Ⅰ portland cement, and waste plastic strips obtained form reclaimed milk containers. The specific objectives of the study were (1) to establish the traditional S-N (stress ratio vs the number of cycles to failure) relationship for the proposed new composite base course, and compare its performance with other traditional stabilized pavement materials, and (2) to quantify the accumulation of fatigue damage with applied loading cycles. The main objective of utilizing plastic strip reinforcement was to inhibit the propagation of tensile cracks, and thus improve the overall toughness and fatigue resistance of the base course material. The cement content in all mixes used in this study was either 4 or 8% by total dry weight of the mixture implying that at least 92% of the base course composite consisted of waste or recycled materials. Flexural fatigue tests conducted on this mixture reinforced with 1.25% (by weight) of recycled plastic strips (51 mm long and 6.3 mm wide) showed that the performance of the composite base course was comparable to or better than other traditional stabilized material used in pavement construction. It was also found that the damage accumulation in this material can be reasonably estimated from the well-known Miner's hypothesis on cumulative damage. The study indicates that the new composite base course consisting primarily of waste products holds considerable promise as an alternative material for the construction and rehabilitation of highway pavements.