Category Archives: Solutions

Construction of new facilities and installations requires quality materials. It is one of the requirements for obtaining durable structures serving humanity with good faith and fidelity for years.

But the reality is that not all construction materials fully comply with these requirements. This especially concerns road construction. The total length of roads in the world is about 64,285,000 km (as of 2013). The development of many countries is also accompanied by improvement of transport infrastructure and, as a consequence, construction of new roads. Therefore, this figure is constantly growing.

Due to the increase in traffic and harsh climatic conditions, traditional binders used in asphalt mixtures no longer provide the necessary durability of roads. In many cases, the durability is two to three times less than standard norm, causing additional costs to perform unscheduled, unbudgeted repairs.

It is much cheaper to use a high-quality material from the start to guarantee endurance. Over the past decade there have been many studies aimed at improving the quality of road surfaces. As a result, it was concluded that it is not necessary to abandon traditional bitumen, but it is necessary to adjust its characteristics by introducing special additives – modifiers. They give future road surface all the characteristics it is so lacking now. In particular: fracture and frost resistance, fatigue endurance, strength, etc. The main advantage of modified bitumen is extending the range of road operation temperatures. Various polymers are used in road construction. The most widely used are sulfur, rubber and crumb rubber.

Modified bitumen quickly proved its competitiveness; it also started to be used in other industries for roofing and waterproofing.

Existing methods for bitumen polymer modification are based on maintaining a high temperature (150-200ºS) and vigorous stirring of components.

When heated, bitumen softens and thermoplastic polymers become viscous fluids. Therefore, the process of mixing bitumen with polymers at high temperatures typically occurs in two stages: the emulsification of softened polymer in liquid bitumen and its subsequent partial or complete dissolution. The nature of polymer dispersion depends on its chemical nature and molecular weight, chemical composition of bitumen and their mixing ratio.

Modern road construction places high demands on the quality of materials. This is especially true for the binders used in preparation of asphalt mixtures.

Pavements made from traditional bitumen can not cope with modern density and intensity of traffic.

Scientists assess the durability of pavements with bitumen-mineral composition, at only 50-70% of normative durability. Low elasticity, insufficient crack resistance and low temperature performance range restrict endurance of bitumen roads in hot summers and cold winters. These phenomena are especially evident in areas with sharply continental climate.

After much research it was found that one of the best ways to extend the life of asphalt pavement is to change the structure and properties of binder. This is achieved by modifying bitumen with polymer additives. With introduction of special substances bitumen receives a number of valuable properties, especially important in the road sector: resistance to aging and aggressive environments, toughness and elasticity. These characteristics do not change in above zero and subzero temperatures.

Special units are used to produce bitumen-polymer compositions. The production occurs as follows. First, materials are loaded into the unit separately. Bitumen is heated to 180°C and pumped into one of the mixers.

Polymers are delivered in sacks and loaded into the blender. Plasticizer is fed at the same time.

Usually, the unit can produce modified bitumen either with or without a plasticizer.

The components are dosed with flowmeters and adjusted by control system according to the formulation of the product.

Colloid mill crushes the pellets into fine particles and mixes them into bitumen.

Finished modified bitumen is pumped into bitumen storage tanks, or into containers for preparation of bituminous mastic.

Mixture of polymer modified bitumen is allowed to stabilize for 60 minutes, which is necessary for swelling of granules.

Offloading to customers or for in-house production is carried out directly from the storage tank. As for the mastic, it is poured directly into containers or packaging for storage of briquettes.

To produce the high quality polymer modified bitumen, GlobeCore developed the UVB-2 unit with production capacity of 4 to 40 m3/h.

The equipment has the following advantages:

• works perfectly with all polymers, waxes and various specific additives known to date, ;
• works with various forms of modifiers: powders, granules, etc .;
• can implement almost any type of bitumen modification;
• additional plasticizers and additives that improve bitumen adhesion can be added during pumping and modification;
• additional amount of polymer can be added when pumping;
• oil heating system can reduce costs.

The progress of humanity is linked with construction of new objects, new networks, etc. In recent years, the scale of construction reached the highest levels.

This also applies to roads. Every year the traffic load on them increases, which puts extra demands on construction materials. First, they must be strong enough. Second, they must withstand long variable loads. The third requirement is to be resistant to different weather and climatic zones. It is understood that these are not the only requirements, but they are fundamental.

Traditionally, petroleum bitumen was used as a binding material in road construction. Up to a certain point, it made for satisfactory coatings. But with the increase in traffic the service life of roads stopped responding to greater requirements.

The need to search for a fundamentally new material, capable of providing high-quality characteristics of the roads, or the improvement of existing (bitumen) characteristics was urgent. Scientists decided to go the second way, with some success.

Improving properties of road bitumen can be achieved by improving the technology of its production or by introducing special additives (modifiers). Studies have shown that improving oxidation technology of tar does not fully satisfy the requirements. But introducing additives of specific nature and in the right amount can improve and consolidate the results achieved .

Modified bitumen, unlike unmodified bitumen, has a number of positive qualities, which include improvement of heat resistance and cold resistance, as well as ensuring reliability and durability of structures.

In most cases, road bitumen characteristics are improved by introducing various kinds of polymeric materials. Apart from those, solid modifiers (mineral powder) are also added to bitumen. The latter stop the binder ruining.

For polymer bitumen modification, GlobeCore developed and manufactures the UVB-2 unit. This equipment produces the highest quality material. Roads built with modified bitumen last longer and withstand harsh weather conditions and intense traffic better.

Depending on the needs of the enterprise, UVB-2 capacity can be specified from 4 to 40 m3/h.

One of the most important elements of a building is the roof. Its function is the protection from rain, heat, cold, snow, pollutants, dust, solar radiation, etc. But in most cases the roof does not only have a protective function. In some ways, it is a “headdress” of the building, a part of its image.

Design and construction of the roof are chosen in full compliance with the functional, operational and regulatory requirements.

The basic criterion for successful selection of roofing is the right choice of construction materials. It is advisable to take into account the opinion of professional builders, as well as the results of object examination and calculation of loads.

Architectural solution of the roof, its shape and slope significantly limit the range of possible materials for roofing. At the same time, it is a particular roofing material and not an architect that dictates the appropriate shape and slope. For example, a tiled roof will have to be flat. Also it severely restricts the angle of inclination: some shingles are laid only on 25-30º slopes , and some – a little more than 45º.

Also taken into account are the climatic characteristics of the region where the building is constructed. After all, it depends on the geographical location of snow load, the force and direction of the wind.

Increasing the slope prevents snow and rain seeping through in strong wind, but it increases wind load and material consumption.

Application of piece roofing materials has been done for many, many years. Nature and the environment dictated the specific type of material used: palm leaves were used in the tropics, slate in the mountains, wood chips in forest areas. But tiles continue to be the most perfect and versatile roofing material. Even today in many cities buildings with tiled roofs remain .

When selecting a material for roofing, the deciding factors are prestige and aesthetics. Since the most reliable material is tile, its various modifications began to appear – soft bitumen and metal. These materials are easier to install, have a pattern similar to that of natural slate roofing and are cheaper in cost.

Also, the choice of roofing is strongly influenced by traditions of the area. For example, the US and Canada prefer classic shingles (soft bitumen shingles), while Russia and Finland go for metal tiles. In Europe, the latter is extremely rare. In Germany, the proportion of this material does not exceed 3%. The favorite is natural tile in up to 80% of cases, natural slate coming second.

The following method is popular for choosing a roofing material . Its criteria are:

• durability;
• economy;
• environmental friendliness;
• ease of installation;
• light weight;
• silent operation;
• beauty;
• snow slide;
• regional adaptation.

Then, each material is given a numerical score on a scale from 0 to 5 based on these criteria. Summing up the numbers and drawing comparisons allows to make an informed decision.

The first synthetic thermoplastic materials entered the market in the middle of the last century (1965).  The SBS-polymer name comes from “styrene- butadiene-styrene”.  This material has a chemical structure with elastic internal block.  This is why SBS-polymers are perfect to be mixed with bitumen.  Polybutadiene chain is formed as a result of such interaction.

Characteristic of these polymers is that polybutadiene and polystyrene are not stratified because they are connected to each other chemically.

What is the impact of SBS-polymers on the properties of bitumen?

Due to the presence of SBS-polymers, bitumen has the optimal flexibility and viscosity at low outside temperatures.

Implementing SBS-polymer as binding agents achieves following results:

• better resistance to permanent mechanical stresses at rising temperatures.  This is achieved by high viscosity provided by the presence of polymer matrix;
• high resistance to cracking at low temperature;
• increased resistance to thermal and mechanical pressure, which is achieved by increasing stiffness;
• increased wear resistance;
• high resistance to aging and improved characteristics of binding agent fragility for porous asphalt.

Experts claim that using SBS-polymers is one of the most effective methods of bitumen modification today.  It allows obtaining pavement surfacing with improved technical and operational characteristics.

Road Bitumen with Polymers

The first patent for modifying bitumen with natural rubber was registered almost 170 years ago. Ironically, it took another 150 years before the modified road bitumen  has taken a worthy place in  road construction.

There were a couple of reasons for this.. Firstly,  the traffic loads on roadway are ever-increasing. Secondly, large polymeric materials are available.

Natural rubber, as the first modifier of road bitumen dispersed well. It’s problem was foaming, but it could be controlled by the way it was added.

Other polymers took some time to become available. Approximately 30-40 years ago first new modification additives came into the market. They have  necessary solubility and structure, and good rheological and mechanical properties. According to experts, to date, polymer modified bitumen covers 10% of  total consumption of bitumen, making it 10 million tones.

Overall, the preliminary cost of asphalt preparation with modified road bitumen is greater than cost for conventional asphalt. So there is an urgent search for cheap modifying additives. Over the past few years the following solutions have been proposed – the use of:

• Polymers from waste;
• Used rubber tires;
• Wax additives;

– Rheology modifiers (i.e. polyphosphoric acid).

Each of these methods has its advantages and disadvantages, so the decision to use a particular additive should be taken individually.

For a successful and cost-effective modification – polymers must meet the following requirements:

• Form three-dimensional network in the polymer phase;
• Recycling;
• Good interaction with road bitumen for significant absorption

For implementation of polymer modified bitumen in road  construction GlobeCore produces UVB-2 installation. This equipment:

• Works with all known to date, polymers, waxes and various specific additives;
• Uses any form of  modifiers : powders, granules, etc .;
• Realizes any formula for bitumen modification;
• Adds plasticizing agents during the modifying process;
• Adding extra polymer during  transfer mode;
• Reduces electrical bill with oil heating system.