Multiscale Laboratory Mechanical Performance of SDA Mixtures with Construction and Demolition Waste Filler

Abstract

The incorporation of waste materials into road materials provides an excellent opportunity for partial reductions in virgin material consumption while providing a valuable alternative destination for the would-be waste. However, the incorporation of these materials and the performance limitations of the resulting asphalt need to be carefully examined, especially with regards to the asphalt cracking susceptibility. The current study focuses on the use of construction waste fillers as partial aggregate replacement in semidense asphalt (SDA) mixtures. Both concrete waste in the form of recycled concrete aggregates (RCA) and mixed construction and demolition (C&D) waste are examined. The indirect tensile (IT) stiffness modulus was found to not be affected significantly by the filler replacement. The IT fatigue resistance was found to be somewhat lower with the waste material using the classical approach, but similar when looking at the damage rate. In addition to the smaller-scale testing, larger-scale testing was conducted on the control and RCA filler mixtures using the Mobile Model Load Simulator (MMLS3), and similar cracking resistance was found for both mixtures while advancing a novel crack length measurement method using digital image correlation. The results showed that the incorporation of RCA filler into semidense asphalt mixtures is a viable solution reducing the need for virgin filler.