Investigation of Fiber-Modified Bituminous Mixes

Abstract

Bituminous pavements provide a resilient, waterproof, load-distributing medium that protects the base course from the detrimental effects of water and the abrasive action of traffic. Bituminous pavements are subject to maintenance as a result of wear, weathering, and deterioration from aging. Flexibility of bituminous pavement permits slight adjustments in the pavement structure, resulting from consolidation of base course or effect of load, without detrimental effect. Hot-mix bituminous pavements are designed by either the Marshall or gyratory method. Development of modified bituminous materials to improve pavement performance has been the focus of several research efforts over the past few decades. Several attempts were made to modify bituminous mixes. The concept of using fibers to improve the behavior of the bituminous mixes is a recent development in the field. This research work compares the effects of polypropylene fiber on bituminous mixes with the help of laboratory investigations. The Marshall stability and flow values have been determined to evaluate the strength and deformation characteristics. To evaluate the field performance, indirect tensile strength, tensile strength ratio, retained stability, and permanent deformation have been determined through tests. With an increase in fiber content, Marshall stability values increase, density values decrease, and optimum binder content slightly increases. The indirect tensile strength increases with an increase in fiber content in the mix. The tensile strength ratio and retained stability increase with an increase in fiber content, indicating improved moisture resistance. Permanent deformation decreases with an increase in fiber content, indicating a decrease in rutting potential.