In the past, the penetration index was defined based on the assumption that thermal sensitivity in the bitumen used in road construction was zero. Bitumen is a thermoplastic material, meaning that it becomes pliable or moldable above a specific temperature and returns to a solid state upon cooling.
Penetration-grade bitumen is mainly used in road surfacing. Bitumen with lower penetration grade is used in the regions with warm climate while higher penetration grade is used in colder weather.
White Lighthouse Petroleum Company is capable of producing different grades of road surfacing bitumen in compliance with national and international standards in its six plants located at Tehran, Tabriz, Arak, Shiraz, Bandar Abbas, and Abadan refineries. Penetration rate bitumen is graded based on penetration and softening point tests. This table describes the physical properties of penetration-grade bitumen based on European standards. Penetration-grade bitumen is mainly used in road construction. During the last two decades of the 20th century, most road construction projects showed inclination for solid bitumen which results in more effective asphalt.
| No. | Indicator description | Testing method | Norm according to TU 113-05-323-77 | The actual value |
|---|---|---|---|---|
| 1 Overall view | cl. 4.1 TU 113-05-323-77 | Colorless or slightly colored liquid without mechanical impurities | Colorless transparent liquid without insoluble impurities | |
| 2 Density at 20 °С, g/cm3 | GOST 18995.1-73 Section 1 | not more than 0,818 | 0.809 | |
| 3 Mass fraction of water, % | Section 2 GOST 14870-77 | not more than 9,0 | 8.9 | |
| 4 Mass fraction of the organic part, % | cl. 4.4 TU 113-05-323-77 | not less than 91.0 | 91.1 | |
| 5 pH (medium) | cl. 4.5 TU 113-05-323-77 | not less than 7.0 | 8.3 | |
| No. | Indicator description | Testing method | Norm according to TU 2421-322-05742746-97 | The actual value value |
|---|---|---|---|---|
| 1 | Overall view | cl. 5.1 TU 2421-322-05742746- 97 | colorless or slightly colored liquid without mechanical impurities | colorless transparent liquid, without mech. impurities |
| 2 | Density at 20 °C, kg/cm3 | GOST-18995.1-73 | not more than 0.825 | 0.813 |
| 3 | Mass fraction of water, % | Section 2, GOST 14870-77 | not more than 12.0 | 7.3 |
| 4 | Mass fraction of the organic part, % | cl. 5.3 TU 2421-322-05742746- 97 | not less than 88.0 | 92.7 |
| 5 | pH (medium) | Instructions for the pH-meter | not less than 5.0 | 5.3 |
| No | Name of the indicator | Technique Test | Standard according to GOST-2222-95 | The actual value |
|---|---|---|---|---|
| 1 | Overall view | cl. 6 GOST 2222-95 | Сolorless transparent Liquid without insoluble impurities | Сolorless transparent liquid without insoluble impurities |
| 2 | Density at 20 °C, g/cm3 | GOST-18995.1-73 | 0.791–0.792 | 0.791 |
| 3 | Miscibility with water | cl. 6.5 GOST 2222-95 | Miscible with water without cloudiness or opalescence | Miscible with water without cloudiness or opalescence |
| 4 | Temperature limits: boiling point, °С 99 % of the product is distilled within, °C | GOST-25742.1-83 | 64.0–65.5 not more than 0.8 | 64,2–64,9 0.7 |
| 5 | Mass fraction of water, % | GOST14870-77(section 2,electrometrictitration | not more than 0.05 | 0.010 |
| 6 | Mass fraction of free acids in equivalent of formic acid, % | GOST-25742.2-83 | not more than 0.0015 %. | 0.0008 |
| 7 | Mass fraction of aldehydes and ketones in equivalent of acetone, % | cl. 6.7 GOST 2222-95 | not more than 0.003 | 0.0020 |
| 8 | Potassium permanganate test, min | GOST-25742.5-83 | not less than 60 | 65 |
| 9 | Chromaticity according to the platinum cobalt color scheme, Hazen units | GOST-29131-91 | not more than 5 | 5 |
