The effect of cement reactive powders on the mechanical response of WMA mixtures

In the current study, two types of reactive powders, namely calcium sulfoaluminate (CSA) cement and ordinary portland cement (OPC), were incorporated into warm mix asphalt (WMA) at 25% volume concentration replacing asphalt binder. The powder materials were added to replace the binder without changing the volumetry of mix design. The performance of the mixtures was then measured and compared to the control mix using laboratory testing. The tests include the workability using a superpave gyratory compactor (SGC), moisture damage and fatigue resistance using an indirect tensile (IDT) test, and thermal cracking resistance using a semi-circular bend (SCB) test. The research results demonstrated that reactive powder-based mixtures show superior resistance to fatigue and thermal cracking, while the workability and moisture resistance were comparable to the control mixtures. The measured fatigue life and low-temperature fracture energy of CSA-based mixes was improved by 62.20% and 9.30%, respectively, when compared to the reference mix. Based on the reported results, it is concluded that using reactive powders in WMA mixtures not only enables a reduction in asphalt binder content but also can improve the mechanical response of the asphalt concrete.