Roller Compacted Concrete for Road Base Layer with RAP and Steel Fibers: Viscous Properties and Description of Experimental Sites

Abstract

A high-performance composite material consisting of reinforced compacted cement concrete including Reclaimed Asphalt Pavement (RAP) has been investigated. This composite material is used as a base layer in combination with an asphalt overlay for heavy traffic roads. Steel fibers are used to minimize crack opening. RAP is added to preserve raw material and to comply with sustainable development, especially in the case of in-situ treatments. Composites with different RAP and fiber content and cement content were studied both in laboratory and on site. The laboratory study is divided into two parts. First, classical standard tests for road concrete were carried out: compressive strength, compressive modulus and tensile splitting strength, with a view to the design of pavement structures to be used on site. Secondly, more comprehensive rheological tests, such as complex modulus and fatigue tests, were performed to obtain a better knowledge of material behavior. Then, on-site behavior was studied from two experimental sites. The presence of bitumen in cement-treated composites induces an increase of viscous properties, observed mainly on the phase angle. These composites respect the time-temperature superposition principle and can be fitted by a visco-elastic rheological model.