Evaluation of natural zeolite as warm mix asphalt additive and its comparison with other warm mix additives

In last decade, warm mix asphalt (WMA) has been used as alternative to hot mix asphalt (HMA) that reduces the temperature of asphalt during production and placement, minimizes greenhouse gases while maintaining the advantages of HMA. This study targets the investigation of natural zeolite as a WMA additive and its comparison with different types of WMA additives (organic, chemical and synthetic zeolite). The bitumen samples have been produced by mixing a 50/70 penetration grade bitumen with different types of WMA additives at various contents. The fundamental and rheological properties of bitumen samples involving different types of WMA additives have been determined by using conventional bitumen test methods and dynamic shear rheometer (DSR).

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► The addition natural and synthetic zeolites reduce mixing and compaction temperature.
► Natural zeolite can be used as an alternative WMA additive to synthetic zeolite.
► WMA additives increase the elastic characteristics of the bitumen.
► 5% zeolites, 3% organic and 2% chemical additive are considered as optimum contents.