Application of NaP1 Zeolite Modified with Silanes in Bitumen Foaming Process

In recent years, global climate change has caused worldwide trends in science and industry toward a focus on the development of modern technologies with reduced environmental impact, including reduced CO₂ emissions into the atmosphere. The technology for producing asphalt mixtures (AM) at lower temperatures (WMA-warm asphalt mix) using zeolite materials for the bitumen foaming process fits perfectly into these trends. Therefore, towards the development of this technology, the research presented in this paper presents the modification process of zeolite NaP1 from fly ash with silanes of different chemical structures (TEOS, MPTS, TESPT) and their application in the foaming process of bitumen modified with polymers (PMB 45/80-55). The scope of the work includes two main novelty elements: (1) the use of zeolite-silane composites in bitumen foaming and (2) polymer-modified bitumen foaming. Chemical characterisation carried out by EDS-XRF, FTIR, and XPS analysis clearly demonstrated the success of the zeolite matrix modification process, which directly resulted in textural changes. Simultaneously, mineralogical analysis carried out by XRD showed the complete retention of the initial phase composition of zeolite matrix. Further studies have shown that the application of zeolite-oxide composites results in less PMB 45/80-55 stiffening without imposing negative effects on its softening point and dynamic viscosity.