The document discusses the aging of bitumen, which is used as a binder in asphalt pavements. It explains that bitumen undergoes both short-term and long-term aging through oxidation and loss of volatiles over time when exposed to heat, light, and oxygen. This aging causes changes in the properties of bitumen like decreased penetration and ductility, and increased softening point, which can lead to deterioration of the pavement. The document also discusses methods to prevent or reduce bitumen aging, like the use of rejuvenators, fillers, and bitumen emulsions in pavement construction and maintenance.

1. GUIDED BY SUSAN ROSE LECTURER DEPT. OF CIVIL ENGINEERING PRESENTED BY NITHANTH.S S7 CIVIL ROLL NO: 37

5. AGING CONCEPTS The amphoterics are the most reactive in terms of reactivity are capable of forming interlinked structures because they have more than one reactive site ( Fig). Mono functional materials with one oxidizable site, can act as chain terminators, limiting the degree of associations. The amphoterics have a large effect on the viscosity of the bitumen; the monofunctional polar molecules do not. .

6. FUNCTIONALITIES PRODUCED BY AGING

8. COMPARISONOF UV AND THERMAL AGING ON PHYSICAL PROPERTIES ON BITUMEN After UV and Thermal aging penetration and ductility value decreased while softening point is increased

9. Degradation rates of physical indices of aged bitumen Figure shows the changes to physical indices of bitumen A and B caused by aging. 1 A is more UV radiation sensitive. Its penetration decreased by 42%.ductlity decreased by 77.6% and the softening points increased by 22.6%,showing poor anti –UV ability. 2 B is not very sensitive to UV but is more thermally sensitive .as only small changes caused by UV radiation but greater changes in ductility and softening points caused by thermal aging can be seen . 3 Variations in the physical indices indicate than bitumen has different sensitivities due to Thermal and UV aging.

10. EFFECT OF THERMAL AND ULTRAVIOLET AGING variation of penetration and viscosity on different samples with storage

13. Surface aged and cracked Rejuvenator emulsion sprayed Penetrates surface Aggregate or sand spread Seal formed with rejuvenated base