Moisture Damage in Asphalt: Analysis Based on the Dewetting Mechanism

• Published in: Journal of materials in civil engineering Vol. 29; no. 6
• Main Authors: Saltibus, Nibert E, Wasiuddin, Nazimuddin M
• Format: Journal Article
• Language: English
• Published: American Society of Civil Engineers 01-06-2017
• Subjects: Additives; Air conditioners; Asphalt; Damage; Dewetting; Moisture; Pavements; Styrenes; Technical Papers
• ISSN: 0899-1561; 1943-5533
• DOI: 10.1061/(ASCE)MT.1943-5533.0001793

AbstractIn this study, the role of the dewetting mechanism in moisture damage of asphalt pavements was investigated. Three main asphalts, and mainly two antistrip additives, were utilized. A unique dewetting-based moisture damage test procedure was developed consisting of a moisture conditioning procedure and quantitative analysis of the dewetting with the use of a microscope and an application software. The dewetting analysis procedure includes measurements of the total dewetted area and number of dewetted holes. It was observed that the dewetting phenomenon occurs primarily under a trapped air bubble in the asphalt film submerged in water. Polymer (styrene butadiene styrene) in PG 76-22M (modified) asphalt did aid in reducing dewetting. At high pH, 10, the Adhere LOF 6500 additive increased dewetting for all three asphalts. The critical film thickness for all three asphalts was estimated experimentally and found to be 300 μm. The findings of this study on understanding the role of dewetting on moisture damage in asphalt pavements will assist in the implementation of a unique dewetting-based moisture damage test procedure and analysis.