2019 CSCE Annual Conference - Laval (Greater Montreal) Conference
Dr. Hassan Baaj, University of Waterloo
Dr. Mohab El-Hakim, Manhattan College
The severe Canadian winter conditions, together with the increase in traffic volumes play the major role in reducing the service life of flexible pavements. Rutting and cracking are probably the most common modes of pavement deterioration in Canada. These two modes forced researchers and engineers to develop several additives and solutions in order to improve the performance of paving materials. In this study, a critical literature review regarding the use of Geopolymers and their application in construction materials is provided. Moreover, an experimental work was conducted to study the rheological and microstructural properties of the PG 58-28 asphalt binder; with different percentages of Geopolymer; 0%, 3%, 6%, and 9%. The effect of Geopolymer curing time on rheological and microstructural properties was also investigated. Rotational Viscometer, Dynamic Shear Rheometer (DSR), and Environmental Scanning Electron Microscopy (ESEM) imaging devices were used to measure the performance of the different modified binders. Results indicated that the increase in the Geopolymer content and the curing time significantly affect the rheological behavior of the asphalt binder by increasing its viscosity, complex shear modulus and failure temperature. Samples with higher Geopolymer percentage exhibited better performance in terms of rutting resistance. Moreover, an improvement in the failure temperature is recorded as of 14.2% and 15.2% for 7 and 14 days curing times, respectively. Furthermore, increasing the percentage of the Geopolymer showed a development in the microstructure of asphalt binder whereby the asphalt binder with 9% Geopolymer showed larger fibril size as compared with the 3% and 6%. Undoubtedly, the Geopolymer has proved its ability to enhance the properties of the asphalt binder.
Keywords: Asphalt Cement, Rheology, Geopolymer, Master Curve, Workability, ESEM