Enhancing the crumb rubber modified asphalt’s storage stability through the control of its internal network structure

Abstract

The current research investigated the effect of the internal network structure developed in the crumb rubber modified asphalt (CRMA) on its storage stability. The authors investigated the influence of asphalt-crumb rubber modifier (CRM) interaction parameters (interaction time, interaction speed, and interaction temperature) on the development of the internal network structure in CRMA. The authors found that the existence of three dimensional (3D) network structures in the CRMA enhanced its storage stability. Fourier Transform Infrared (FTIR) Spectroscopy was utilized to determine the nature of CRM components responsible for the development of 3D network structure in the liquid phase of CRMA. This was achieved by monitoring the changes of the IR distinctive peaks in the CRMA liquid phase. Dissolution tests and thermo gravimetric analysis (TGA) were carried out on the extracted CRM after interaction with asphalt to determine the role of CRM dissolved amounts and released components on the development of 3D network structure in CRMA. The asphalt-CRM interaction parameters were found to be essential to induce the formation of the 3D network structure within the liquid phase of the CRMA through controlling the swelling, dissolution and release of CRM components into the asphalt liquid phase. The existence of 3D network structure in the CRMA had determinant impact on the enhancement of its storage stability.