Microstructural Mechanical Analysis of Warm-Mixed Reclaimed Semiflexible Pavement Materials with Interfacial Weakening Effect

Hua Tan,Weian Xuan,Huang Wenke,Meng Guo

doi:10.1155/2021/1055006

Hua Tan, Weian Xuan + Show 2 more

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https://doi.org/10.1155/2021/1055006

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Abstract

Warm-mixed reclaimed asphalt pavement technology, as an environmental recycling method to reuse waste materials, has been widely investigated around the world. However, the skeleton of the reclaimed asphalt mixture is unstable due to the existence of the reclaimed materials. Semiflexible pavement has been successfully used in heavy traffic area due to its high rutting resistance. For combination with these two methods, a warm-mixed reclaimed semiflexible pavement material was proposed in this study. In order to investigate the interfacial weakening effect of the warm-mixed reclaimed semiflexible pavement material in a microstructural perspective, an image-based two-dimensional microstructural finite element model was presented. Results show that the maximum compressive stress of the new and RAP aggregates and cement mortar with interface is greater than that without interface and the compressive stress of the material increases when considering the interface. Besides, the maximum compressive strain of the material with interface is greater than that without interface and the strain values in the models with interface at all three positions are greater than those without interface.

Highlights

Asphalt concrete, which has the advantages of smooth surface, low noise, and convenient maintenance, is one of the most common types of pavement surface materials used in the world
Reclaimed asphalt pavement (RAP) technology can realize the reuse of waste materials and reduce the use of new aggregates. e RAP technology is to add appropriate amount of new asphalt binder, new aggregates, and rejuvenation into the waste asphalt material and remix them to form a new asphalt mixture. e most commonly used way to regenerate the reclaimed asphalt pavement is to mix them at a temperature of 170°C, which leads to the old asphalt binder in the recycle materials to age again. is will greatly weaken the performances of the asphalt mixture
E reclaimed asphalt pavement (RAP) materials provided by Guangzhou Municipal Engineering Maintenance Office Co., Ltd. were tested according to the Chinese specifications (JTG F41-2008) in order to obtain the RAP aggregate properties and retained asphalt content. e RAP materials, which are composed of coarse aggregates, fine aggregates, and asphalt binder, were dried and sieved before testing

Summary

Introduction

Asphalt concrete, which has the advantages of smooth surface, low noise, and convenient maintenance, is one of the most common types of pavement surface materials used in the world. A large amount of asphalt mixture waste from the maintenance of asphalt pavement has caused great pollution to the environment. Great efforts have been made to reuse the waste asphalt mixture by researchers [2,3,4,5,6,7,8]. Reclaimed asphalt pavement (RAP) technology can realize the reuse of waste materials and reduce the use of new aggregates. E RAP technology is to add appropriate amount of new asphalt binder, new aggregates, and rejuvenation into the waste asphalt material and remix them to form a new asphalt mixture. Hot mixing of asphalt mixture consumes a lot of energy, increases carbon dioxide emissions, and produces a lot of exhaust gases that are harmful to the environment [9,10,11]

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