The Effect of a Zeolite Addition to Modified Bitumen on the Properties of Stone Matrix Asphalt Lärmarmer Mixtures Produced as Warm Mix Asphalt

This paper presents the properties of an SMA LA (stone matrix asphalt Lärmarmer) mixture based on the polymer-modified binder PMB 45/80-55, formed by the addition of zeolites (synthetic zeolite type Na-P1 and natural zeolite-clinoptilolite). The compositions of the SMA 11, SMA 8 LA and SMA 11 LA mixtures based on modified bitumen with PMB 45/80-55 (reference mixture) or PMB 45/80-55 with Na-P1 or clinoptilolite were determined. Their resistance to permanent deformation, water sensitivity, water permeability and susceptibility to changes in texture and skid resistance during the period of use were verified. Adding zeolites reduced the production temperature by as much as 15 °C for the SMA 11 LA mixtures and 20 °C for SMA 8 LA. The addition of zeolites did not significantly affect the resistance to permanent deformation, the water permeability or the mass loss. The mixtures with clinoptilolite were resistant to the harmful effects of water, while the mixtures with Na-P1 proved more sensitive to water. Water permeability tests showed a higher permeability for SMA 11 LA compared to SMA 8 LA due to the higher nominal aggregate size. The Cantabro test showed greater particle loss for SMA 11 LA than for SMA 8 LA. A skid resistance and macrotexture analysis indicated that the SMA LA layers required special maintenance on the road due to the clogging of pores in the mix structure.