A study on performance of modified bitumen using different types of blacks

• Published in: I-Manager's Journal on Civil Engineering Vol. 14; no. 4; p. 35
• Main Authors: Sottegari, Prasanth Kumar, Amarendra, Kumar S., Gopala, Raju S. S. S. V.
• Format: Journal Article
• Language: English
• Published: Nagercoil iManager Publications 01.12.2024
• Subjects: Acetylene; Additives; Asphalt mixes; Asphalt pavements; Bitumens; Carbon; Carbon black; Commercial vehicles; Creep recovery; Embrittlement; Flexible pavements; Fracture mechanics; Life cycle costs; Physical properties; Rheological properties; Rheology; Rheometers; Surfacing; Thin films; India
• ISSN: 2231-1068; 2249-0779
• DOI: 10.26634/jce.14.4.21571

Flexible pavements with bituminous surfacing are widely used in India. The high traffic intensity in terms of commercial vehicles, overloading of trucks, and significant variations in daily and seasonal temperature of the pavement have been responsible for early development of distress like rutting, cracking, bleeding, shoving, and potholing of bituminous surfacing. A factor which causes concern in India is very high and very low pavement temperature conditions in some parts of the country. Under these conditions, the bituminous surfacing tends to become soft in summer and brittle in winter. Studies have revealed that the properties of bitumen and bituminous mixes can be improved or modified with the incorporation of certain additives or blend of additives. These additives are called modifiers, and the bitumen premixed with these modifiers is known as modified bitumen. Use of modified bitumen in the top layers of the pavement is expected to significantly enhance the life of the surface and extend the time of the next renewal. Various studies have revealed that use of modified bitumen in construction or maintenance of bituminous roads significantly improves the pavement performance and is cost-effective when life-cycle cost is taken into consideration. Various percentages of carbon black, furnace black, and acetylene black are introduced during the preparation of the modified bitumen. Subsequent evaluations encompass physical properties, rheological properties, fatigue characteristics, and microscopic properties of both base asphalt and black-modified bitumen. Rheological tests conducted through the dynamic shear rheometer determine the performance grade. Multiple stress creep recovery testing assesses creep recovery. The thin film oven test, representing short-term aging, is applied to both the base asphalt and modified binder, followed by repeated physical and rheological tests using the dynamic shear rheometer for carbon black, furnace black, and acetylene black. Overall, the use of black as a bitumen modifier can result in improved performance and longevity of asphalt pavements, making it a valuable tool in asphalt mix design and pavement engineering.