Asphalt binders is also known as asphalt cement binders or simply asphalt cement. It plays an important role in the construction of flexible pavement because of its good adhesive property it can hold the aggregates together. When the lubricants and fuel are removed by distillation of crude oil, the thick heavy residue which left behind is known as Asphalt Binders. This heavy residue then passes through many stages like oxidation and steam reduction until it reached to a desired specification for the asphalt binders. Sometimes small amount of polymers are also added while passing through these processes, just to get high performance. If these polymers are added then it is called Polymer modified binders. Asphalt binders tend to be terribly stiff and brittle at cold, thick fluid at hot temperature and rubbery semi solid at intermediate temperatures. The pavements which contains binders which are too soft can be affected at high temperature such as rutting and shoving. The performance of pavement largely depend upon the microstructure of asphalt. It is necessary to study the physical microstructural properties of asphalt. In this modern era technology is becoming so advanced that it becomes easy for us to study these kinds of properties. One of the best challenges to understanding and predicting asphalt behavior is thanks to the high level of variability between totally different asphalt sources ensuing from factors like asphalt chemical composition and microstructure. In order to properly characterize micromechanical properties of asphalt, it’s necessary to possess an intensive understanding of the standard and current ways accustomed characterize the chemical composition and microstructure of asphalt. In order to properly characterize micromechanical properties of asphalt, it’s necessary to own a radical understanding of the normal and current strategies accustomed characterize the chemical composition and microstructure of asphalt. To study the microstructure properties of asphalt binder different microscopy techniques are used such as atomic force microscope (AFM), transmission electron microscope (TEM), fluorescence microscope and scanning electron microscope (SEM). Depending on the mode of operation, SEM may be accustomed give insight into surface topography, part separation and mechanical properties resembling adhesion and stiffness. Though SEM has been used to check biological samples for a number of decades, SEM remains a comparatively new tool for investigation micromechanical behavior of asphalt. to produce direct info concerning the mechanical properties of varied structural regions, SEM may be employed in spectroscopic analysis mode to live the Nano-scale indentation response of asphalt.
In the developing country like Asian nation, growth of urbanization may be a very important method ultimately results in the vehicle growth and therefore the load on the pavement will increase that results in distress of the pavement. Major downside in pavement seen is that the aging of the pavement and to beat such downside a shot shaped is formed compound changed hydrocarbon exploitation completely different style of compound. So, asphalt is a complicated mixture of different sizes and polarities of molecules due to which microstructural knowledge is still incomplete. As the physical properties of asphalt binders largely depend upon the microstructure so the performance of pavement is also related to this. A detailed data of microstructure is required to know the physio-chemistry of hydrocarbon, which may function the direct link between the molecular structure and therefore the rheological behavior. In order to properly characterize micromechanical properties of asphalt, it’s necessary to own a radical understanding of the normal and current strategies accustomed characterize the chemical composition and microstructure of asphalt.