Tag Archives: road construction

GlobeCore’s Road Building Units

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Road-building machines are used to:

  • lay an earth roadbed;
  • develop traffic interchanges and sidewalks; and
  • build traffic structures.

As usual, there are many different road building units on the hi-tech market, so it can be difficult to make the right choice.  That is why it is recommended to take into consideration the following criteria in order to choose equipment that meets all of your needs:

  • volumes, intensity and characteristics of road construction projects;
  • operating conditions; and
  • preventive and corrective maintenance requirements.

To get a better understanding of road building units, it it recommended to have a look at the followong statistics: The road density of France and Germany is 1800-1830 km per 1000 km2; Lithuania, Latvia, Estonia, Poland and India – 1070-1175 km2, the USA- 670 km2.

One of the primary tasks of highway engineering is to pave new roads and maintain the existing ones which are performed by road building units.  Preparation of high-quality road construction materials is also of great importance.

GlobeCore road construction units produce bitumen emulsion that is used as a binding material.

GlobeCore’s bitumen emulsion production unit UVB-1 and modified bitumen production unit UVB-2 are manufactured based on different designs.  These units may have an open or enclosed frame, different capacity and configuration to meet the customer’s needs.  GlobeCore units allow for production of  binders that meet the worldwide quality standards in the road construction industry.  As a result, the quality of road pavement is increased, the road construction season is extended, energy resources and financial expenditures are reduced, and hazardous waste is eliminated.

GlobeCore technology is a cost-effective way to build and repair roadways.

Equipment For Road Maintenance and Repairs

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The following is the list of the units, used to maintain and repair roads:

(1)    recyclers for asphalt concrete;

(2)     asphalt cold milling machines;

(3)     snow ploughs;

(4)    joint filling machines;

(5)     bush cutters;

(6)    sand-spreading machines; and

(7)     bitumen emulsion units;

The recyclers for asphalt concrete are meant for repairing potholes on roads made of mastic asphalt.  Additionally, the recyclers may be used to produce asphalt concrete and mixtures based on concrete or used to transport hot bitumen.

The asphalt cold milling machines reclaim asphalt pavement.  That means they remove the parts of the surface of the paved area to fill them with the new cement or asphalt concrete.

The snow plough is considered to be one of the most effective machines to clear the roads of snow and remove the snow accumulations along the roads.  Some designs of snow ploughs allow for loading snow into carrier vehicles.

The joint filling machines automatically apply the tack coat prior to the asphalt laying.

Sand-spreading machines are units that are mounted on tractors to spread bulky materials such as salt and sand.  These machines are applied to improve road safety during snow and ice storms.  The grass on the shoulders of roads or trees with a thickness of more than 80-100 mm may be cut by the special machines called “bush cutters.”

There are two types of equipment for bitumen emulsion production:

(1)    The GlobeCore UVB-1 line of units are designed for cationic and anionic bitumen emulsion production.  This construction material has gained a great popularity in the road construction industry and is used to construct and repair roads, waterproof  roofs, and eliminate dust on the pit roads.

(2)    The GlobeCore UVB-2 units are used for the modificartion of polymer bitumen.  The application of polymers for bitumen modification makes it possible to meet the needs of the road construction industry and improve every aspect of new road pavement.

Modified bitumen is widely applied when producing asphalt concrete with improved properties to increase the durability and rutting resistance of the road surface. Both bitumen emulsion units UVB-1 and UVB-2, are produced under the GlobeCore trademark.

Road Construction Equipment

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Today, scientific literature gives several alternative classifications to road construction equipment.  They are all based on two main criteria – the application area and the purpose of the equipment.

The following is one of the generally accepted and widespread classifications.

All road construction equipment includes:

  • machines for mining and processing rock material;
  • machines for production and transportation of concrete mixtures, bitumen and bitumen emulsions;
  • machines for road and aerodrome construction;
  • machines for compacting road construction material; and
  • machines for road maintenance and repair.

The machines for rock mining are applied to develop the deposits of the raw material for road surface construction.  This kind of equipment includes pneumatic drills, rock drilling machines, grinders, and mills.

Such units as (1) concrete mixing machines, (2) metering units, (3) containers, (4) additive production units, (5) ready-mix trucks, (6) bitumen storage tank, (7) transit bitumen carriers, and (8) bitumen spraying machines are considered to be the equipment for production and transportation of concrete mixtures, bitumen and bitumen emulsions.

In this class of equipment, special attention should be paid to the GlobeCore UVB-1 unit which is used to produce bitumen emulsions.  Bitumen emulsions are considered to be the most effective road construction material since it allows for significant energy and bitumen saving and is characterized by eco-friendliness and reliability.

Apart from the UVB-1 line of units, GlobeCore has also produced the UVB-2 units which are designed for the modification of polymer bitumen.  The properties of the asphalt concrete mixture are influenced by the properties of the modified bitumen as one of the most important components.

A non-exclusive list of machines for road and aerodrome construction include (1) pavement profilers; (2) concrete spreaders; (3) concrete pavers; (4) pavement finishing machines; (5) film-forming materials distributor; and (6) asphalt spreaders.

Roads and highways are maintained and repaired using such road construction equipment as street washers, street sweepers, marking machines, road heaters, and milling machines.  If it is impossible to perform a particular operation using the units listed above because of  their size, special mechanical hand tools can be applied.

Generally speaking, a hand-driven machine includes such main parts as (1) an engine; (2) a function-generating mechanism; and (3) a working body.  Such a mechanized tool is controlled by an operator.  This type of machine is small, convenient, serviceable, safe and efficient.

Road Construction Units

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It was the beginning of the 20th century when mankind first tried to mechanize the work it was performing during road construction projects.  As a result of this effort, the first road construction machines began to appear.  The design of a dredger ship was introduced in 1809 in St Petersburg and the design of a steam driven excavator in 1835.  Even with all those advances however, the road construction industry initially developed very slowly.  As of 1839, there were only 7 excavators in the entire world.

The grinding machine was first presented in 1858, the elevating grader in 1875, and the grader in 1887.  The latter two being horse-drawn units.

The latest breakthroughs in the history of the road construction industry were connected with the invention of the caterpillar track and diesel engines.  In 1912, the first crawler-mounted excavator was put into service.

There has been a great leap in the road construction industry due to the discoveries made in the 20th century.  As a result, in the hi-tech market today there is a great variety of automated or semi-automated road building machines.  They have allowed for significant cost savings and manual labor reduction while building and repairing roads and highways throughout the developed and developing world.

Before paving a roadway, it is necessary to perform the following  operations:

(1)    to cut the trees, bushes; and

(2)    to remove stumps.

Special units such as brush breakers and stump diggers can be fixed to tractors or other vehicles to perform the tasks listed above.  A scraping machine is designed to lift, move, and unload soil.  A bulldozer is a tractor, equipped with a blade for moving earth.  It is meant for digging and pushing large quantities of soil for short distances.

Sometimes, sets of road construction units are used to pave the roads with asphalt concrete.  The modern asphalt concrete mixer and an asphalt spreader are among that set of construction units.

The asphalt concrete mixers blend sand with bitumen when the asphalt spreaders pave the road with asphalt concrete.

Polymer bitumen modification is considered to be a very important processing step that can performed on GlobeCore’s UVB-2 units.  They produce bitumen as well as asphalt concrete mixtures with predefined properties to extend the service life of the road pavement.  The concrete spreaders and concrete pavers are mostly used when paving the road with cement concrete.

The following is the list of the road construction units that are used to maintain and repair roads:

(1)    heater-planer;

(2)    surface planning machine;

(3)    road drag;

(4)    motor roller;

(5)    snow-plough;

(6)    sand-spreading machine; and

(7)    snow-loader and other units.

Such units as ballast tamping machines, track-laying machines and cribber adzes are used to build and repair railways.  The ballast tamping machine is used to pack the track ballast (crushed stone, sand, gravel) under the railway tracks.  The track-laying machine is meant for mechanized  rail and sleeper laying and cribber adzes are used to cut side channels along the rail routes, and clean road ditches.

The units listed above are energized from the energy source, located on the locomotive. The latter also serves as a means of transport.

Bitumen Modification as a Way to Extend the Period Between Road Repairs

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Today, asphalt and concrete has been widely applied when paving roads and highways.  Recently, there have appeared a great number of potholes because of the increased number of heavy load-carrying vehicles.  Unfortunately, potholes occur all year round, but more intensively in spring.

In practical terms, road pavement failures are mainly treated in a frost-free season.  Delayed pothole treatment can result in the intensification of the road failure process: not only asphalt and concrete layers, but also pavement layers are destroyed.

All this has a negative impact on the service life of the road pavement and road traffic safety.  It is very troublesome to perform road construction works at low temperature since the road construction materials are characterized by poor adhesion to the road surface.  In such a way, application of cold asphalt concrete and emulsion mixtures will not be efficient when repairing road surfaces.

The statistics show that when applying the technologies described above, the road pavement will need repairing in a year because of the destruction in the junction of the road surface and road patch or defects of the road construction materials.

Cold asphalt concrete mixtures distinguish themselves through the following advantages:

(1)    Long-term storage;

(2)    Long-distance transportation; and

(3)    Road construction projects performed at low temperatures.

Due to the above listed characteristics, this construction material has gained a widespread acceptance in the road construction industry.  Many specialists agree on the point that modified asphalt concrete is a good alternative to hot or mastic asphalt.  Cold asphalt concrete mixtures haven’t enjoyed a wide popularity because of their poor physic and chemical performance characteristics.  High quality and timely repairs and long service life of road surfaces requires operation with liquid bitumen that most corresponds to the current conditions of roadway usage.  Such substances may be obtained by modifying bitumen by adding special substances that improve the durability and other characteristics of cold asphalt concrete.

Technically, bitumen can be effectively modified by the GlobeCore UBV-2 units.

This equipment includes:

(1)    two reactors;

(2)     colloid mill;

(3)     oil heating and bitumen supply blocks;

(4)     cabinet with a control panel;

(5)     polymer supply block;

(6)     controllable bitumen valves; heating system;

(7)     adhesive additive supply block;

(8)    plasticizer supply block; and

(9)    a platform to load polymer.

The UVB-2 modified bitumen units can be serviced either outside or inside an enclosed building with a balanced system of ventilation.

GlobeCore equipment provides for production of modified bitumen and polymer-bitumen binders that improve the quality of road construction projects and extend the period between road repairs.

Skid Mounted Bitumen Modification Unit

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The asphalt based road systems can no longer ensure the durability of the wearing surface because of  the increased  amount of heavy load carrying vehicles on our roads.  In the not so distant past, this problem could be solved by using crushed aggregates of average size or stone mastic asphalt.

The rapid development of motor vehicles has made the road builders take more effective measures to make the road surface more resistant to (1) high temperature extremes; (2) cracking at low temperatures; (3) surface scaling; (4) potholing; and (5) aging.

It has been known that the quality of a bitumen-concrete mixture is largely determined by the quality of the bitumen binders.

It was therefore, the researchers and road builders that decided that it would be reasonable to substitute polymer modified bitumen for traditional bitumen.  This tendency first appeared in the 1960s.  Since then, there has been an intensive, but, unsystematic development of modified bitumen.

The use of different polymers and a constant search for new ways to connect them with bitumen were the main tendencies of this development.  A clear theory of bitumen modification first appeared only at the end of the 20th century.

The theory states that the most effective modifiers are thermo-elastoplast polymers and that the substitution of  modified bitumen for traditional bitumen will benefit the service life of road surface pavement materials.

GlobeCore  has developed skid mounted bitumen modification units, designated as UBV-2, to produce high quality modified bitumen.  These units are made of separate standard blocks that can be replaced or added to meet the individual customer’s order and needs.  It helps to find a solution to any technological problems.

The main unit 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) a control systems.

UVB-2(block)_1

Fig.1. The main unit for modified bitumen production

All of these units are mounted in spatial relays that allows them to be transported  by any means of transport.  Additionally, these units can be completed with a “Block of plasticizer and adhesive additive supply” (Fig. 2) and (or) “Block of bulk materials input” (Fig. (3).

podacha_plastifikatora_1(2)

Fig.2. Block of plasticizer and adhesive additive supply

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Fig.3. Block of bulk materials input

“The block of plasticizer and adhesive additive supply” is an autonomous unit consisting of 3 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) bitumen supply pump; (4) screw-type feeder; (5) tank-receiver of bulk materials with mounted load cells; and (6) a control system.

The blocks, described above, can operate independently as well as as a part of a set (Fig.4).

UVB-2

Fig.4. Skid Mounted Bitumen Modification Unit

This set may also be equipped with (1) modified bitumen storage tanks with volume of 15 and 30 m³; (2) container-type storage tank with volume of 32 m³; (4)  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 input and output of modified bitumen to meet the customer’s order.

All the units have reverse bitumen pipes that allow the operators to rinse equipment with clean bitumen when the main works are done.  Modular design of this equipment allows a quick mounting and dismounting when moving to another site.