Company Group ABZ-1

Modified bitumen is bitumen with additives from special polymers. It has found its application mainly in road surfaces. Its appearance was due to purely technical reasons. The increase in vehicle traffic increased the load on the road surface, and conventional bitumen, which has a lower performance, often did not withstand these loads. Thus, a more advanced material was required, with better indicators of strength in relation to the road surface and more convenient in storage, use, etc. The addition of polymers to bitumen solved this problem. Modified bitumen has increased elasticity, which makes it more resistant to deformation. The temperature difference for modified bitumen ranges from one hundred degrees, while for ordinary bitumen there is only sixty degrees between brittleness and softening. In addition, practice has shown that even after ten years of use as an asphalt concrete pavement, modified bitumen does not lose its viscosity.

A number of polymers for various purposes are used to modify bitumen. They can be conditionally divided into several groups. Thermoplastics soften when heated and harden when cooled. At normal temperatures, modified thermoplastic bitumen increases its viscosity and hardness, while maintaining elasticity at the same level.

Elastomers, in accordance with the name, increase the elasticity of bitumen at normal temperatures, and with large temperature fluctuations, they can keep it at a high level. Bitumen with elastomers retains its properties in frost and temperatures up to two hundred degrees Celsius. However, the storage of this type of bitumen is associated with a number of features. So, it must be constantly mixed, since elastic polymers constantly tend to separate from the bitumen base.

The third type of modified bitumen is a combination of the first two. Thermoelastics are deformed and softened only at very high temperatures. Also, to modify bitumen, natural and synthetic resin, asphalts, and some inorganic salts are often added to it.

A great influence on the characteristics of modified bitumen is exerted not only by the composition of the polymers introduced into it, but also by the method of introduction itself. That is why bitumen modification is carried out only in refineries or in special installations where this process is strictly controlled.

Bituminous-latex emulsion has proven to be excellent binders for asphalt mixtures during repair work. However, today there are no universal compositions of bitumen emulsions that would best suit the conditions of work. Therefore, in practice, they resort to changing their characteristics by introducing various polymers. This process in the technical literature is called modification, i.e. by combining bitumen emulsion with synthetic polymer additives.

Latex itself is a natural or synthetic dispersion of rubber particles in water. As part of a water-bitumen emulsion, latex increases the strength and elastic properties of the material. As a rule, latex polymers are combined with the aqueous phase and emulsified with bitumen directly during the preparation of the bitumen-latex emulsion. But also the bitumen itself can be modified with latex, or latex polymers prepared in the form of an independent emulsion can be introduced into the finished bitumen emulsion.

Latex polymers can be of cationic, anionic and nonionic types, depending on the charge of its particles. It is imperative to take into account the compatibility of the latex and the emulsion, since the aqueous polymer dispersion must correspond to the characteristics of the emulsifier.

One of the most well-known is a latex additive, which makes it possible to obtain a product such as a bitumen-latex emulsion at the output. The addition of latex makes it possible to increase the strength and mechanical properties of the emulsion. In structure, it is a natural or synthetic dispersion of rubber in water.

When preparing emulsions, it is imperative to take into account the type of latex polymer, which is determined by the charge of its particles. After all, not every latex (cationic, anionic and nonionic) can be compatible with a particular type of emulsion.

In addition to road construction, bitumen-latex emulsions are successfully used as waterproofing materials for building structures, protecting them from water penetration and its subsequent destructive effect.

The advantage of using bitumen-latex emulsions is noted by a number of qualitative indicators: the period of operation of roads increases, the temperature range of operability expands, the time of layer formation is reduced, high elasticity and resistance to deformations are provided. To improve the adhesion of layers, experts recommend adding special adhesive additives to latex-bitumen emulsions.