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Going towards sustainable pavement construction, asphalt industries constantly give their effort to implement Warm Mix Asphalt (WMA) by adding the chemical warm asphalt additive (CWAA). This can lower its energy consumption and pollution by reducing the mixing and compaction temperatures of the asphalt mixture without affecting its properties. Several studies have been conducted evaluating the properties of the WMA, however, little documented research on the rheology of the binders containing CWAA is available especially when dealing the sources of binders. In this paper, the tests for rheology characteristics of the Malaysian asphalt binder containing CWAA were conducted with rotational viscosity and for dynamic mechanical analysis with dynamic shear rheometer (DSR). The results of the investigation indicated that the CWAA had a significant reduction of required heat for mixing and compaction effort and also shows lower permanent deformation when compared to the control binder.

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In recent years, flexible pavement construction technology has relied heavily on the use of reclaimed asphalt pavement (RAP). However, the brittle nature of RAP, which stems from the use of an aged asphalt, has introduced numerous complexities into the process, with important implications to pavement service life. The properties of the aged asphalt can be rejuvenated to improve the performance and the behavior of RAP mixtures. This paper presents a review of past works that have used rejuvenating materials with RAP, including their benefits and drawbacks, as well as the optimal approach to increase RAP content in asphaltic mixtures. The method of rejuvenating aged asphalt and the mechanism of rejuvenation are also reviewed. The findings of this review can be used to predict the current and future challenges in the regeneration of RAP mixtures using rejuvenating materials.

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In recent times both natural and synthetic rubber were blended with bitumen with the hope of producing a more durable hot mix asphalt. Although the application of natural rubber (NR) in bitumen modification have started long time ago prior to crumb rubber; only few literatures that completely characterised its performance are found today. This review aims to remind researchers and paving agencies on the benefits of NR rubberised asphalt. The study draw attention to NR production process and its unique properties, how NR was used to solve four major asphalt pavement failures namely rutting, fatigue, thermal cracking, and moisture susceptibility. It also presents barriers limiting the application of NR in bitumen modification with possible solution. Lastly, the concept of applying NR in warm mix asphalt was introduced.

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