PERFORMANCE GRADE (PG)
From October 1987 to March 1993, the Strategic Highway Research Program (SHRP) was conducted in the United States. The program focused on developing new methods for assessing the performance of bitumen binders. The research created a new Superior Performing Asphalt Pavements (Superpave) method.
The main specifications of this method included:
- Using the efficiency criterion for bitumen binders and asphalt concrete
- Considering climatic conditions in the application of bitumen
The problems studied in this method are as follows:
- Winter low-temperature bitumen cracking is not related to loading
- Bitumen fatigue cracking due to loading
- Summer high-temperature bitumen deformation due to loading
The primary objective behind determining the new specifications was to facilitate the purchase of bitumen products of better quality because these specifications would clearly describe the product for potential buyers. The new specifications also guarantee the proper performance of bitumen in coating. Climatic conditions are essential factors in the efficiency of coating, but limited research has been conducted on this issue due to limited time and similar weather conditions. Moreover, they would not be precise if the loading factor was not considered. Producers worldwide have started producing this type of bitumen, and MCP is the prominent supplier. Having installed SHRP systems, Maccoran Petroleum Company can sell bitumen to its customers using the PG method. It is worth reminding that penetration was used as a factor for bitumen grading. In performance grade, the focus is on the mechanical specification of bitumen, while experimental parameters are involved in penetration grade. In the GCC countries, pen grade is more common, but in some cases, PG has to be used for better performance. Today, a PG is defined as polymer-modified and pure bitumen based on environmental conditions and temperature. A more comprehensive PG range means higher resistance and more favorable specifications. Maccoran Petroleum Company can supply all these grades. This company first conducted climate zoning in the GCC countries to specify the appropriate bitumen for different geographical zones.
High Temperature Performance | Low Tempereture Performance |
---|---|
PG 46 | -34, -40, -46 |
PG 52 | -10, -16, -22, -28, -34, -40, -46 |
PG 58 | -10, -16, -22, -28, -34, -40 |
PG 64 | -10, -16, -22, -28, -34, -40 |
PG 70 | -10, -16, -22, -28, -34, -40 |
PG 76 | -10, -16, -22, -28, -34 |
PG 82 | -10, -16, -22, -28, -34 |