Caitlin Purdy

Fuel Resistance Asphalt Binder: Mixing Procedure and Fuel Damage Resistance

Most of the biopolymers are made from animal waste. Animal waste is treated and converted in a form of glue generally known as Hide Glue or Bone Glue (BG), which is prepared from animal protein. This study focusses of developing fuel resistant asphalt using biopolymers i.e. protein based polymers. A procedure to develop fuel resistant asphalt for commercial use and its performance evaluation was conducted in this study. Mixing procedure of BG was evaluated and refined and multiple fuel resistance tests were performed to evaluate the impact of bone glue modification on resistance to fuel of neat binder. It was determined that BG-binder mixing equipment developed in earlier studies was appropriate. Optimum BG dosage to develop FRA was found to be higher than the BG dosage recommended in earlier studies to develop mechanistically better performing asphalt binder. Fuel solubility resistance test was used to select the optimum BG dosage. Fourier Transform Infrared Spectroscopy results proved that water was completely evaporated using the mixing procedure developed for the preparation of FRA. Fuel damage resistance test revealed that BG modification not only improved the intermediate to high temperature characteristics of the neat binder but outperformed the conventional polymer modified asphalt binder in resistance to fuel damage.

Evaluation of the morphological and rheological impacts of cross-linking agents in polymer modified binders

This study was initiated with the aim of evaluating the relative impact of different cross-linking agents on the rheological and morphological properties of polymer modified asphalt binders. To complete this objective, two cross-linking agents (an aromatic oil and silicon oxide elemental sulfur) were selected for evaluations. The cross-linking agents were then added to a styrenebutadiene-styrene (SBS) polymer modified binder (virgin PG 70-22) at different dosages. The selected cross-linking dosages were 2 and 4% by weight of virgin binder. The SBS, virgin binder, and cross-linking agents were mixed together for 90 minutes using a high shear mixer. The morphology of the modified binder was then tested using a florescent microscope and the rheological properties were evaluated using the dynamic shear rheometer (DSR) to determine the dynamic shear modulus master curves and the multiple stress creep recovery (MSCR) properties of these binders. The results show that with the increase in aromatic oil cross-linking agent dosage, there is a reduction in shear modulus results. In addition, the florescent microscope images show that there seems to be an improvement in the compatibility between the virgin asphalt and SBS in the presence of the aromatic oil extracts.