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Fatigue, creep and erosion are among the factors which destroy the asphalt mixture and modifying the asphalt binder via additives such as crumb rubber, sulfur, carbon, as well as natural and synthetic polymers has been done in order to improve the strength of asphalt mixture. Knowledge in the field of nanotechnology along with its capability and attractiveness for application as nanoparticles in different industries such as asphalt industry has attracted great attention in recent years. In this study, specific percentages of TiO2nanoparticles, namely 2, 4, and 6, were added to the asphalt binder as the nanocomponent. Done physical common tests such as penetration degree, softening point, flash point and viscosity of the base asphalt binder and modified asphalt binder, the bending beam samples composed of origin asphalt sample and modified asphalt sample with 4% TiO2nanoparticle were subjected in different micro strains to fatigue loads. Results of four point bending fatigue test showed that the addition of TiO2nanoparticles to the asphalt binder increased the fatigue strength in the asphalt samples. Modified asphalt binder is stiffer, more viscous than original asphalt binder and due to TiO2nanoparticles more temperature tolerance and load bearing capacity, modified Asphalt is more resistant under fatigue loads.

Modification of the asphalt binder is one approach taken to improve Asphalt pavement performance. Rutting is one of the most important factors that could reduce the life of asphalt pavements.Nowadays, the application of nanotechnologyto achieve materials that are more resistant is expanding in asphalt pavement thatNano-TiO2is among the most exciting and promising classes of materials discovered recently. The purpose of this study is laboratory research on the effect of Nano-TiO2in improving Bitumen property and rutting resistance in Asphalt pavement under dynamic loading. For this purpose, the wheel-tracking test was carried outon ordinary and Nano-TiO2modified hot mix asphalt samples.The results illustrate that using Nano-TiO2in asphaltbinder samples cause to an improvement in ruttingdepth in comparison with theordinarymixtures.

Modification of the asphalt binder is one approach taken to improve aged pavement performance. To make the most of maintenance budgets, many agencies have resorted to the use of asphalt rejuvenators as an alternative to revive aging and brittle asphalt pavements. The purpose of this study is laboratory research on the effect of asphalt emulsion in restoring the original properties of aged asphalt pavement. For this purpose, the repeated load axial test is carried out on conventional asphalt samples and aged asphalt samples containing rejuvenator agents in different stress and rejuvenator percentage. Bitumen aged with RTFO according to ASTM-D2872 and the optimum bitumen of 5.5% were considered. The softening point and penetration tests, to examine the effect of rejuvenator in asphalt mixtures modification, On the basic, aged and modified aged bitumen were performed. The results represent that asphalt emulsion as a rejuvenator material in aged asphalt samples because of suitable performance improve aged asphalt permanent deformation resistance and aged bitumen Rheological property.

Recycling of bituminous mixes is extending worldwide with the aim of conserving natural resources and the environment. Rejuvenating agents are generally used in recycling processesin order to soften the aged binders in mixes. Cutback bitumens have been used in Iran mainly in preparing conventional cold mixes. However, the long term good performance of these cold mixes in various parts of the country has shown less hardening of these mixes, compared with conventional HMA mixes. In this research the application of a cutbackbitumen has been investigatedas a rejuvenating agent in mixes containing laboratory aged binders. A 60-70 penetration grade bitumen from Refinery of Tehran was aged under Thin Film Oven Testing (TFOT) conditions. Asphalt Concrete samples were prepared using TFOT aged and virgin binders. Additional samples were prepared using the aged binders together with various amounts of a slow curing SC-250 cutback bitumen from the above refinery. The compacted four inchdiameter samples were tested under static creep testing. The results showed promising effects of the cutback binder in rejuvenating the aged mixes. Based on the results of this study, a mix design criteria wasset for recycled mixes containing cutback bitumen as the rejuvenating agent.