Effects of diatomite on the properties of asphalt binder

Abstract

Modified asphalt binders were prepared by melt blending with different contents of diatomite. Fourier Transform Infrared (FTIR) Spectroscopy was used to test the effects of diatomite on chemical properties of asphalt binder. The effects of diatomite on the physical properties and dynamic rheological behaviors of the modified asphalt were investigated. The high temperature storage stability and aging properties of the modified asphalt binders were also studied. Experimental results indicated that there is no chemical reaction occurred between asphalt binder and diatomite. The storage stability tests indicated that the asphalt modified with diatomite is very stable when diatomite content is less than 20%. With the enhancement of the content of diatomite to asphalt, both viscosity and complex modulus of modified asphalt binders increased rapidly at high temperatures. Furthermore, the diatomite modified asphalt binders exhibited lower phase angle when temperature below to 5°C. As a consequence, the viscoelastic properties of the diatomite modified asphalt binders was modified, which improve its resistance to deformation at high temperatures and the resistance to thermal cracking at low temperature.