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Home → All Courses → Engineering and Technology Courses → Highway and Roadway Maintenance and Management → Flashcard

What specific testing procedures are used to determine the effectiveness of asphalt rejuvenators?



Asphalt rejuvenators are materials applied to aged asphalt pavements to restore some of the original properties of the asphalt binder. Several testing procedures are used to determine their effectiveness. Penetration testing (ASTM D5) measures the consistency or hardness of the asphalt binder. Rejuvenators should increase the penetration value, indicating a softer binder. Viscosity testing (ASTM D4402) measures the resistance of the asphalt binder to flow at different temperatures. Rejuvenators should decrease the viscosity, indicating a more fluid binder. Dynamic Shear Rheometer (DSR) testing (AASHTO T 315) measures the viscoelastic properties of the asphalt binder, including its stiffness and phase angle, over a range of temperatures and frequencies. This test can assess the rejuvenator's ability to restore the binder's flexibility and resistance to rutting and cracking. Bending Beam Rheometer (BBR) testing (AASHTO T 313) measures the low-temperature stiffness and creep properties of the asphalt binder. Rejuvenators should improve the binder's low-temperature performance, reducing the risk of thermal cracking. Tensile strength testing measures the force required to break a sample of asphalt mixture. Rejuvenators should increase the tensile strength, indicating improved cohesion and resistance to cracking. Moisture susceptibility testing (AASHTO T 283) assesses the resistance of the asphalt mixture to moisture damage (stripping). Rejuvenators should improve the mixture's resistance to moisture damage. Field performance monitoring involves tracking the condition of the treated pavement over time and comparing it to untreated control sections. This provides the most reliable measure of the rejuvenator's effectiveness. These tests are performed on asphalt binder extracted from the treated pavement, or on asphalt mixtures prepared with rejuvenated binder, to evaluate the rejuvenator's ability to restore the desired properties.