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2. PROPERTIES OF ASPHALT CONCRETE asphalt mixture shows severe temperature susceptibility: high-temperature rutting, media temperature fatigue low temperature cracking damage. Therefore, asphalt mixture should be modified in some way to promote its further application. 2

3. SOME TYPES OF THE MODIFIED ASPHALT CONCRETE Rubber asphalt Fiber asphalt:  Polypropylene fiber  Polyester fiber  Asbestos (mineral) fiber  Cellulose fiber  Carbon fiber  Glass fiber 3

4. CARBON FIBER ASPHALT Properties of Carbon Fiber  Diameter 7.5 – 7.8 μm  Tensile Strength 3.2 Gpa  Base Polyacrylonitrile  Temperature of Carbonization 1400 oC  Cost 15–35 $/kg 4

5. Influence of carborn fiber on the property of asphalt concrete  Increase the properties of bituminous mixtures stability  improve structural resistance to distress occurring in road pavement due to traffic loads.  Improve fatigue life and permanent deformation of bituminous mixtures by improving mix stiffness. 5

6. Some research shown that: the fiber content of 0.4% by weight of total mix resulted in highest performance in terms of stiffness, resistance to permanent deformation and fatigue; Significant increases in stiffness and rutting resistance However, due to the advanced technology involved in their production, use of carbon fibers can be expensive 6

7. POLYESTER FIBER Properties of Polyester Fiber Diameter: 25± 5 um Gravity: 1.36-1.38 g/cm3 Color: White Lenth: 6mm, 12mm Tensile strength: 500Mpa 7

8. Influence of polyester fiber on the property of asphalt concrete due to :  their effects of absorbing bitumen  The interlacing of the fibres vertically and horizontally increases the elasticity of the asphalt mix  their three-dimensional random distribution in asphalt mixes improve the high-temperature stability notably, adhering to the mineral aggregates, strengthen the resistance of asphalt mixes to environmental disruption and water damage. help Asphalt to be flexible at low temperature.. → prevents the onset and propagation of cracks, improves the low- temperature performance of the asphalt mix significantly. block the propagation of cracks and improve the fatigue resistance of asphalt mixes. 8

9. CELLULOSE FIBER 9

10. improves the deformation resistance extends the service life of the pavements considerably fix the binder to the aggregates surface and therefore prevent de-mixing during transport and laying Cellulose is used in Stone matrix asphalt, Porous asphalt → application areas include:  Airport Infrastructures  Motorways  Intersections  Bus stops  Racing Circuits 10

11. RUBBER ASPHALT CONCRETE Some sulfur in rubber reacts with oxygen during heating and mixing into binder → change the structure and composition of binder’molecules → influence high temperature behavior of asphalt 11

12. Influence of natural rubber on the property of asphalt concrete increase viscosity helps increase cohesion between aggregates and bitumes binder → reduces stripping for the mixtures. increase softening point of asphalt cement → reduce deformation, bleeding, rutting and increase road pavement stability at high temperature. Concentrated latex could help increase elasticity of asphalt cement at low temperature. reduce aging for asphalt cement according to the amount of concentrated latex added. reduce temperature susceptibility as penetration index (PI) increases by the amount of concentrated latex added. → adding concentrated latex made the mixtures work well on service temperature at 70 o C 12

13. PROPERTIES OF HIGH PERFORMANCE ASPHALT CONCRETE Stability in severe temperature  Reduce rutting in high temperature  Flexible at low temperature  High deformation resistance 13