Nowadays, the problem of road surface quality is of vital importance because of an increased amount of heavy load carrying vehicles on the roads. As a result, the road surface pavement is quickly destroyed and requires considerable financial expenditures to repair and restore the road system. The organic binders, that resulted from the modification process, are applied to improve the quality of the roads and extend the service life of the road surface. Bitumen is used as a basic binder in the road construction industry.
Bitumen is an organic material with a defined set of properties. The properties allow its use as a “glue” when preparing a bitumen-concrete mixture. Plasticity and heat resistance are the main performance characteristics of bitumen.
Modification of bitumen is the process of adding some of the substances that change the performance characteristics of bitumen. In practical terms, polymer materials are added to bitumen in order to improve such characteristics as durability, adhesiveness and material yield strength. The whole set of these factors benefits the quality of the road extends the service life service of the road surface.
Chemical substances known as “sulfur,” “rubber,” “polyethylene,” “polypropylene,” “polystyrene,” “polyurethane,” and “olefine copolymers” are used as modifiers in many parts of the world.
Special equipment is used to blend bitumen with a modifier. GlоbeCоre has developed and is still producing skid mounted modified bitumen equipment in the UBV-2 line. The UBV units are assembled as individual blocks that may be replaced or added to meet the customer’s needs. This equipment helps to solve a wide spectrum of technological problems.
Fig.1. The main unit for modified bitumen production
The main block for modified bitumen production (Fig.1) consists of: (1) colloid mill; (2) premixing container for “SBS”(styrene-butadiene-styrene) and bitumen; (3) bitumen supply pump; (4) screw-type feeder of “SBS”; (5) tank-receiver for “SBS” with mounted load cells, and (6) control systems. All of these units are mounted in spatial relay allowing it to be transported by a wide variety transpotation systmes. The UBV units can be completed with a “Block of Plasticizer and Adhesive Additive Supply” (Fig. 2) and/or a “Block of Bulk Materials Input” (Fig. 3).
Fig.2. Block of plasticizer and adhesive additive supply
Fig.3. Block of bulk materials input
“The Block of Plasticizer and Adhesive Additive Supply” is an autonomous unit consisting of three pumping points:
(1) bitumen; (2) plasticizer; (3) adhesive additive; (4) an injector mixer; (5) a heat-transfer device; (6) a piping system; and (7) a control system.
“The Block of Bulk Materials Input” is also an autonomous unit consisting of: (1) a colloid mill; (2) an input bulk materials unit; (3) a bitumen supply pump; (4) a screw-type feeder; (5)a tank-receiver of bulk materials with mounted load cells; and (6) a control system.
The blocks described above can operate independently and as a part of a set. (Fig.4)
Fig.4. Skid Mounted Bitumen Modification Unit
This set may also be equipped with: (1) modified bitumen storage tanks with a volume of 15 and 30 m?; (2) a container-type storage tank with a volume of 32 m?; and (3) an oil heat generator with capacity of 70-500 kW (kilowatt) that operates on any kind of fuel or electricity.
The set may be equipped with pumping stations designed to receive input and send output of modified bitumen to meet the individual customer’s order and needs .
All the units have reverse bitumen pipes that allow the oparator to rinse equipment with clean bitumen when the main works are completed.
The “Modular Design” of the UBV-2 unit provides for quick mounting and dismounting when moving to another area.