Asphalt Cement Grade
The American Association of State Highway and Transportation Official (AASHTO) has recognized the Asphalt Cement Grade of Bitumen as one of the main kinds of viscosity grade bitumen.
The Viscosity Grades are used to describe asphalt mixtures. The Asphalt Cement Grade (AC), supplied and exported by PETAS®, is in perfect conformity with the ASTM stan- dard. The AASHTO maintains two sets of Viscosity Grade bitumen standards. The first series is asphalt cement, denoted as AC. The number that follows indicates the mate- rial’s viscosity in hundreds of poises at 60 degrees Celsius. The second series is aged residue, represented by AR.
Measuring viscosity is a more accurate way of specifying binder consistency and deter- mining the temperature susceptibility of the bitumen. The viscosity of a liquid is defined as the inverse of its fluidity. The bituminous material’s fluid property is defined by vis- cosity. Cold climates require low viscosity AC-2.5 and AC-5, whereas hot regions are best served by high viscosity grades ranging from AC-10 to AC-40.
| Test | Viscosity | |||
|---|---|---|---|---|
| AC-10 | AC-20 | AC-30 | AC-40 | |
| Dynamic viscosity @60°c (poise) | 1000±200 | 2000±400 | 3000±600 | 4000±800 |
| Kinematic Viscosity @135°c(Min, Cst ) | 250 | 300 | 350 | 400 |
| Penetration ,25°c,100g 5s,min | 80 | 60 | 50 | 40 |
| Flash Point °C | 220 | 230 | 230 | 230 |
| Solubility in trichloroethylene (min %) | 99.0 | 99.0 | 99.0 | 99.0 |
| Test on residue from thin film oven test viscosity @60°,max,poise | 5000 | 10000 | 15000 | 20000 |
| Ductility ,25°c,5cm/min/cm | 75 | 50 | 40 | 25 |
| Spot test | _ | |||
| Naphtha solvent | Negative | |||
| Naphtha -xylene solvent ,xylene percentage | Negative | |||
| Heptane-xylene solvent ,xylene percentage | Negative | |||