Investigating the effect of nanomaterials on the Marshall properties and durability of warm mix asphalt

Warm mix asphalt (WMA) has gained significant interest recently as a more sustainable and environmentally friendly alternative to conventional hot mix asphalt (HMA). WMA is produced at lower temperatures, reducing energy consumption and greenhouse gas emissions. However, there is an ongoing need to improve the durability of WMA to satisfy the expanding demands of modern road infrastructure. Nanomaterials that possess unique characteristics of high surface area and reactivity could serve as promising additives for improving the performance of WMA. This research aims to investigate the effect of four nanomaterial types on the Marshall properties and durability of warm mix asphalt (WMA). These types are; nano silicaNS, nano carbonate calcium NCC, nano clayNC, and nanoplatelets NP. For each type of Nanomaterial, three contents are tried as follows; NS(1%, 3%, and 5%), NCC(2%, 4%, and 6%), NC(3%, 5%, and 7%), and NP(2%, 4%, and 6%) by weight of asphalt cement. Following the Marshall mix design method, the optimum asphalt cement content is determined; thereafter the optimum dosage for each nanomaterial is obtained based on the highest Marshall stability value. The durability of the control mix (no nanomaterial) and modified mixtures have been compared based on moisture damage, resilient modulus, and permanent deformation. These properties are evaluated using indirect tensile strengthITS and uniaxial repeated load tests. The findings of this research emphasize the potential of nanomaterials to improve the Marshall properties and the durability of WMA significantly. Also, the results showed that using nanomaterials to construct asphalt concrete surface course extended the service life of pavement structures. Compared to CM, modifying asphalt concrete by one of the nanomaterials, NC, NS, NCC, and NP, improved the design life by 59.6, 43.1, 24.4, and 12.2%, respectively. However, the improvement rate for each property depends on the nanomaterial dosage and type. Therefore, this work provides a basis for producing more durable and sustainable paving mixtures using nanomaterials to offer better resistance to distress.