Interfacial bond strength and moisture induced damage characteristics of asphalt mastic-aggregate system composed of Nano hydrated lime filler

The present study was undertaken to investigate the impact of a unique combination of fillers on interfacial bond strength and moisture-induced damage potential of asphalt mastic. One asphalt binder (AC-30), three fillers including Basalt (B), Hydrated Lime (HL), and Nano-Hydrated lime (NHL) were selected to prepare asphalt mastics for a wide range of filler-binder (f/b) ratio (0.6 to 1.2). The dosages of HL and NHL were considered 0%, 5%, 10%, 15%, and 20% by weight of asphalt binder, and the dosage of B filler was adjusted to meet the respective f/b ratio. The interfacial bond strength and moisture-induced damage potential of asphalt mastic specimens were determined using the Bitumen Bond Strength (BBS) test. The BBS test parameters inferred that both B-HL and B-NHL filler combinations can enhance the bond strength and moisture damage resistance of asphalt mastic. Besides, asphalt mastic composed of B-NHL filler can be less susceptible to bond failure and moisture damage with improved adhesion and cohesion properties than B-HL filler. Additionally, asphalt mastic composed of a lower percentage (10%–15%) of NHL filler showed better bond strength and moisture damage resistance over mastic composed of a higher percentage (15%–20%) of HL filler. Asphalt mastic prepared with an f/b ratio less than 1.0 was found to be suitable to achieve better performance considering the moisture-induced damage properties. Grey relational analysis (GRA) method was used to analyze the correlation degree between filler properties and moisture damage properties of asphalt mastics. Based on the GRA results, Rigden voids and specific surface area are suggested to be the two most influential properties on the moisture-induced damage potential of asphalt mastic.