Rutting and moisture-induced damage potential of foamed warm mix asphalt (WMA) containing RAP

Syed Ashik Ali,Musharraf Zaman,Mohammad Ashiqur Rahman,Rouzbeh Ghabchi

doi:10.1007/s41062-021-00528-7

Abstract

Despite significant economic and environmental benefits, performance of warm mix asphalt (WMA) containing reclaimed asphalt pavement (RAP) remains a matter of concern. Among the current WMA technologies, the plant foaming technique (called “foamed WMA” in this study) has gained the most attention, since it eliminates the need for chemical additives. In the present study, the laboratory performance, namely rutting and moisture-induced damage potential of foamed WMA containing RAP were evaluated and compared with those of similar hot mix asphalt (HMA) containing identical amount of RAP. Dynamic modulus, Hamburg wheel tracking (HWT) and flow number tests were performed to assess the rutting resistance of the mixes. Also, stripping inflection point from HWT tests and tensile strength ratio after AASHTO T 283 and moisture induced sensitivity test (MIST) conditioning were used to evaluate the moisture-induced damage of asphalt mixes. It was found that MIST conditioning effectively simulates the moisture-induced damage and can capture the propensity of asphalt mixes to moisture damage more distinctly compared to AASHTO T 283 method due to application of cyclic loadings. The foamed WMA was found to exhibit higher rutting and moisture-induced damage potential due to lower mixing and compaction temperatures compared to HMA. However, the increase in RAP content was found to reduce rutting and moisture-induced damage potential for WMA. Therefore, the lower stiffness of foamed WMA may be compensated with the addition of stiffer binder from RAP.

Highlights

Construction of sustainable and environment-friendly transportation infrastructures results in saving natural resources, conserving the environment and reducing energyThis manuscript is a part of the corresponding author’s MS thesis.consumption [1, 2]
These temperatures were selected based on the previous studies conducted on foamed warm mix asphalt (WMA) technology and the current practice used by the local asphalt producers [1, 18]
The performance of foamed WMA prepared using different types of asphalt binders, such as polymer-modified binders, might be different from those observed in this study

Summary

Introduction

Construction of sustainable and environment-friendly transportation infrastructures results in saving natural resources, conserving the environment and reducing energyThis manuscript is a part of the corresponding author’s MS thesis.consumption [1, 2]. Construction of sustainable and environment-friendly transportation infrastructures results in saving natural resources, conserving the environment and reducing energy. This manuscript is a part of the corresponding author’s MS thesis. The WMA technologies improve the workability of asphalt mixes using chemical additives, organic additives, and water-based or water-containing foaming processes [1, 2, 7]. These technologies reduce the mixing and compaction temperatures of traditional hot mix asphalt (HMA) by about 2–40 °C [8,9,10]. The laboratory performance of WMA containing RAP is still a matter of concern

Methods

Results

Conclusion