Rock materials take up to 90% of the asphalt concrete composition. The Superpave technology analyzes the consistent and inconsistent properties of these materials. Consistent indicators considered are:

• the number of clay and dusty particles;
• the angularity of large and small grains;
• the number of grains of various shapes.

Inconsistent indicators considered are:

• frost resistance;
• wear resistance;
• the content of toxic components.

The final combination is checked for compliance with the standards. The right choice of rock materials makes a reliable asphalt concrete that withstands deformation and fatigue changes.

Any asphalt concrete mix consists of mineral materials: bitumen, sand, crushed stone, and gravel. The durability of the final mixture largely depends on the quality of the binding bitumen. Superpave technology assumes an accurate selection of bitumen not according to outdated standards, but according to a specially created PG Grade scale. The PG classification helps to determine the bitumen binder suitable for a particular road section. The choice of bitumen depends on:

• features of natural conditions;
• density of load during automobile traffic;
• the highest summer and winter temperatures in the last 20 years.

Indicators used to evaluate the parameters of the binder are:

• density;
• plasticity;
• dynamic viscosity;
• creep resistance.

The compliance of these parameters is checked during laboratory tests.

In cold form
PG bitumen in cold form does not require special conditions during transportation, it is stored in open areas in stacks up to 3 rows in height. The shelf life in cold form is at least 12 months from the date of manufacture. For longer storage, it is necessary to check the compliance of the material with the declared properties.

In hot form
Hot binders are shipped to cleaned tank trucks with a heat-proof jacket. Storage should be carried out in sealed containers heated with thermal oil with periodic stirring by mechanical means or by means of circulation pumps for at least 2 hours a day. Before use, the binder should also be mixed for 2 hours. Temperature conditions are observed to avoid thermal degradation and aging of the material.

Short-term storage (up to 2 weeks)
The recommended temperature for short-term storage of bitumen binders of PG grades is 160-180°C.
Bitumen binders should not be overheated above a temperature of 185 °C.
Reducing the storage temperature to 150 °C during periods when there is no production of asphalt concrete mixture will minimize the possible risks of thermal degradation of the polymer that is part of the Bitumen binder.

Long-term storage (more than 2 weeks)
We do not recommend storing Bitumen binders for a long time at a temperature of 160-180 °C. However, when this is unavoidable, it is necessary to evaluate the quality of the Bitumen binder every 7 days for compliance with the data specified in the quality certificate.
The recommended storage temperature for Bitumen binder grades PG should be 100-110 °C. This minimizes the negative effects of thermal and oxidative degradation and reduces energy costs.
After long-term storage, bitumen binders of PG grades are allowed to be used only after mixing at 160-165 ° C for 1-2 hours. Pump recirculation or vertical slow-speed agitators installed in storage tanks can be used.
Cold packaged storage is the most optimal and best way to preserve the properties of the binder.

Storage of bitumen binders of PG grades should be carried out in containers with oil heating and thermal insulation. Heat pipes and electric heating are not recommended due to the high risk of polymer degradation.

Pumping station requirements
Pumping of Bitumen binder grades PG is carried out using a pump and pipelines equipped with oil heating at a temperature of at least 135-140°C. The pump must be designed for temperatures up to +200 °C and viscosity of the pumped materials up to 5 Pass.

Obtaining an asphalt concrete mixture
When obtaining an asphalt concrete mixture based on a Bitumen binder of the PG brand, the temperature of the binder itself is on average 160-185 ° C (the exact value should be taken from the quality passport for BB according to PG), and the temperature of the mixture is 170-185 ° C. Asphalt concrete mix based on PG Superpave should be transported by trucks with maximum thermal insulation.

Paving of asphalt concrete mix
The minimum temperature of asphalt concrete mix when unloading from a truck into an asphalt paver bunker should be 155-165 ° C. The temperature of the beginning of compaction of the asphalt concrete mixture after the passage of the paver should be 145-160 ° C (the exact value should be taken from the quality passport).
It is necessary to use rollers with pneumatic tires, smooth rollers and vibratory rollers, depending on the type of asphalt concrete coating that is being arranged. Paving should be carried out immediately after asphalt concrete.
The high viscosity of the Bitumen binder PG at low temperatures requires a special (short) sealing time. The boundary temperature of the new pavement, after which the sealing stops, should be 100 °C.
The average paving time is 20-35 minutes, depending on weather and temperature conditions. The density must be monitored during the entire paving time using a portable density meter.