Investigating the Mechanical Behavior of Reclaimed Asphalt Pavement (RAP) Bases in Large Scale Test Box

The present study aims to investigate reclaimed asphalt pavement (RAP) materials for utilization for a pavement base layer material with the goal towards increasing the reutilization of materials and the movement towards increased pavement sustainability. Reduced cost for materials and transportation of materials, overall environmental benefits and many other advantages have led to increased interests in utilizing RAP in pavements including as base materials for highway/roadway construction projects. The potential advantages of utilizing RAP as an unbound base material are known; however, its overall application is still limited partially due to the lack of systematic evaluation studies for the parameterization of RAPs mechanical behavior in pavement design. With this in mind, the current investigation focuses on the resilient modulus (Mr) properties of RAP aggregates in terms of a material’s elastic response. Experimental data from tri-axial stress tests on specimens consisting of RAP, aggregates and a mixture of both materials are investigated. A number of constitutive models for the description of mechanical behavior of RAP materials are investigated. The required procedures for determining the constitutive constants of the constitutive models is outlined for the aforementioned materials. A comparative analysis is applied, and the related results are evaluated. The main conclusion is that RAP materials can be utilized as a base material in the framework of pavement sustainability, as its behavior under loading conditions are similar to virgin aggregate (VA) materials and can be simulated by using appropriate constitutive models for pavement design processes.

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A Comprehensive Review on the Replacement of Virgin Material using Reclaimed Asphalt Pavement (RAP) Material in Flexible Pavements

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/1006/1/012041 ◽

2020 ◽

Vol 1006 ◽

pp. 012041

Author(s):

Pala Gireesh kumar

Keyword(s):

Asphalt Pavement ◽

Flexible Pavements ◽

Reclaimed Asphalt Pavement ◽

Virgin Material ◽

Comprehensive Review ◽

Reclaimed Asphalt

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

Innovative Infrastructure Solutions ◽

10.1007/s41062-021-00528-7 ◽

2021 ◽

Vol 6 (3) ◽

Author(s):

Mohammad Ashiqur Rahman ◽

Rouzbeh Ghabchi ◽

Musharraf Zaman ◽

Syed Ashik Ali

Keyword(s):

Asphalt Pavement ◽

Warm Mix Asphalt ◽

Environmental Benefits ◽

Reclaimed Asphalt Pavement ◽

Chemical Additives ◽

Flow Number ◽

Damage Potential ◽

Asphalt Mixes ◽

Reclaimed Asphalt ◽

Wheel Tracking

AbstractDespite 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.

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