Age-Dependent Flexural Properties of Fiber Reinforced Concrete Used in Thin Overlays

Abstract

This paper presents measured age-dependent flexural properties of fiber-reinforced concrete (FRC) as are used in the design of thin overlay pavements. A laboratory investigation was performed to quantify the pavement design properties, particularly residual strength ratio of FRC as a function of age. Four different types of structural macro-fibers, made of steel or polypropylene, and of different lengths or aspect ratios were investigated. Also different fiber volume contents from 0%, 0.5%, and 1.0% were studied for all fiber types and ages. The results confirmed that there is a significant agedependency to the residual strength ratio. The short steel FRC at high fiber volume content was the only mixture which showed constant residual strength ratio as a function of time. All other FRC mixtures exhibited a reduced residual strength ratio when tested at later ages.