Determination of Mixing and Compaction Temperatures ... - ijcebm

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Viscosity (Pa·s) Viscosity (Pa·s) International Journal of Civil Engineering and Building Materials (ISSN 2223-487X) Vol. 2 No.4 2012 © 2012 International Science and Engineering Research Center 100.00 10.00 1.00 0.28 0.17 0.10 0.01 100.00 10.00 1.00 0.28 0.17 0.10 0.01 0.28±0.03 Viscosity lines 0.17±0.02 Viscosity lines 125 135 145 155 165 175 185 195 205 Temperature (°C) Fig. 1 Viscosity versus temperature for Portland cement and No.70 petroleum 0.28±0.03 Viscosity lines 0.17±0.02 Viscosity lines 162 0.3 dust to binder ratio 0.6 dust to binder ratio 0.9 dust to binder ratio 1.2 dust to binder ratio 1.5 dust to binder ratio 0.0 dust to binder ratio Compaction range Mixing range 0.3 dust to binder ratio 0.6 dust to binder ratio 0.9 dust to binder ratio 1.2 dust to binder ratio 0.0 dust to binder ratio Compaction range Mixing range 125 135 145 155 165 175 185 195 205 Temperature (°C) Fig. 2 Viscosity versus temperature for hydrated lime and No.70 petroleum
Viscosity (Pa·s) 10.00 1.00 0.28 0.1 0.10 International Journal of Civil Engineering and Building Materials (ISSN 2223-487X) Vol. 2 No.4 2012 © 2012 International Science and Engineering Research Center 0.28±0.03 Viscosity lines 0.17±0.02 Viscosity lines 0.01 125 135 145 155 165 175 185 195 205 Temperature (°C) Fig. 3 Viscosity versus temperature for limestone and No.70 petroleum 163 0 dust to binder ratio Compaction range Mixing range 0.3 dust to binder ratio 0.6 dust to binder ratio 0.9 dust to binder ratio 1.2 dust to binder ratio 1.5 dust to binder ratio Determination of asphalt mixtures compaction and mixing temperatures. Asphalt mixtures mixing and compaction temperatures are determined at elevated temperatures from plain asphalt viscosity – temperature charts at equiviscous lines 0.170±0.02 Pa·s and 0.280±0.03 Pa·s. The measurement concepts can be extended to asphalt mastics because the viscosity is a well defined function of temperature and mineral filler to binder ratio content within the cordinates defined in the method stated in ASTM D 2493 for unmodified binders in the equi-viscous range [5]. A reasonable determination of the asphalt mixtures mixing and compaction temperature master curve from asphalt mastics viscosity data is important to avoid construction problems, due to heat damage of asphalt as well as oxidation if mixed at excessive temperatures, and lead to the release of unacceptable levels of “blue smoke” and cause difficulties in compaction. Using viscosity data generated for each type and content of mineral filler, viscosity-temperature graphs are developed for each mineral filler and mixing and compaction temperature values read off at each mineral filler content based on 0.170±0.02 Pa·s and 0.280±0.03 Pa·s. Equi-viscous lines. Fig. 4 shows the mixing and compaction temperature master curves developed from viscosity data of the three mineral fillers. Depending on the type and content of mineral filler recommended for use with No.70 (Penetration grade) bitumen, the required asphalt mixtures mixing and compaction temperatures can be read off from the graph. Asphalt cements within the same penetration grade would produce similar asphalt mixtures mixing and compaction temperatures with the same binder type but a lower grade mixed with mineral fillers determined using the equi-viscous concept. Viscosity - temperature measurements concept can also provide useful data for temperature susceptibility of asphalt cements although different methods are available to evaluate temperature susceptibility of asphalt cements, furthermore temperature indexes vary and depend on the temperature range selected for the calculation of such indexes. Temperature-Viscosity susceptibility is commonly used, because of its universality and fundamental nature, and is preferred over the empirical methods utilizing either penetration measurements or penetration and viscosity measurements at different temperatures. The interaction between filler particles and the asphalt can be viewed in two ways: physical and chemical interaction. Physical interaction between fillers and asphalt refers to formation of stiffened matrix. In chemical interaction, certain fillers might be an active material and possibly react with the asphalt thereby altering the property of the asphalt filler mastic [6,7].
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Determination of Mixing and Compaction Temperatures ... - ijcebm

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