Abstract
The use of waste materials has been increasingly conceived as a sustainable alternative to conventional materials in the road construction industry, as concerns have arisen from the uncontrolled exploitation of natural resources in recent years. Re-refined acidic sludge (RAS) obtained from a waste material—acidic sludge—is an alternative source for bitumen. This study’s primary purpose is to evaluate the resistance of warm mix asphalt (WMA) mixtures containing RAS and a polymeric additive against moisture damage and rutting. The modified bitumen studied in this research is a mixture of virgin bitumen 60/70, RAS (10, 20, and 30%), and amorphous poly alpha olefin (APAO) polymer. To this end, Marshall test, moisture susceptibility tests (i.e., tensile strength ratio (TSR), residual Marshall, and Texas boiling water), resilient modulus, and rutting assessment tests (i.e., dynamic creep, Marshall quotient, and Kim) were carried out. The results showed superior values for modified mixtures compared to the control mix considering the Marshall test. Moreover, the probability of a reduction in mixes’ moisture damage was proved by moisture sensitivity tests. The results showed that modified mixtures could improve asphalt mixtures’ permanent deformation resistance and its resilience modulus. Asphalt mixtures containing 20% RAS (substitute for bitumen) showed a better performance in all the experiments among the samples tested.
Highlights
For the past several years, the asphalt industry’s technological improvements have been increasingly explored in an attempt to overcome the increasing concerns about global warming and rising energy consumption
warm mix asphalt (WMA) is a sustainable technology in the pavement industry that allows the mixing and compaction temperatures to be reduced by 10–38 ◦ C compared to the conventional hot mix asphalt (HMA)
The results suggest that the use of these two recyclable materials reduces environmental damages but improves the resistance of the tire-modified asphalt mixture to moisture damages [15]
Summary
For the past several years, the asphalt industry’s technological improvements have been increasingly explored in an attempt to overcome the increasing concerns about global warming and rising energy consumption. Utilizing warm mix asphalt (WMA) and recycled materials in the road construction industry are two measures aiming at achieving this objective [1]. Limited funding for the road infrastructure construction and maintenance has urged engineers and researchers to evaluate the mechanical properties of pavements using recycled materials [2]. WMA is a sustainable technology in the pavement industry that allows the mixing and compaction temperatures to be reduced by 10–38 ◦ C compared to the conventional hot mix asphalt (HMA). The WMA brings about substantial energy savings, resulting in diminished asphalt mix production expenses and noxious gas emissions [3,4]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
