Bitumen & Asphalt

Additional Details

These are natural petroleum-derivative products. Bitumen is obtained by distilling petroleum, whereas Asphalt comes from natural rocks soaked in petroleum residue.

At ambient temperature they are solid or semi-solid materials with a plastic consistency and strong adhesive characteristics. At higher temperatures, their consistency becomes more like liquids, even though very viscous.

Their chemical nature is not completely known, but enough to use them profitably. These products have been used for over a hundred years in building, both for road surfaces and as waterproof roofs (sheathing, emulsions, suspensions and more).

They have indisputable advantages, such as excellent adhesiveness to many materials, water tightness, a low solubility level in water, good mechanical features in a temperature range which is not too high (from 0°C to a maximum of 40-50°C).

Their main defects are the mechanical features outside of this range. At low temp eratures, bitumen (or asphalt) loses its plastic features and becomes glassy. It therefore breaks easily and is no longer suitable to support wear and stress. On the contrary, at temperatures above 50°C (approximately, depending on the type of Bitumen or Asphalt) it becomes too plastic with scar ce mechanical consistency. It does not break, but is not able to withstand mechanical stress and wear, thus quickly deteriorating.

Moreover the products are almost insoluble in water, but not totally. This is caused by the formation of a liquid film (water - bituminous substances) sticking to the surface of the manufactured products which creates problems of low friction between the ground and wheels of vehicles. In time all of this has led to the need of modifying bitumen to improve its characteristics, both at low and high temperatures and to provide innovative materials capable of resolving seriously dangerous situations such as aquaplaning.

To this aim, for the past decades polymer modifiers have been introduced to the bitumen product which are capable of reducing or even eliminating the defects mentioned above. There is no ONE product which can fully resolve all of the problems linked to the materials we are talking about, but keeping in mind the various defects which we wish to eliminate, the most suitable family of polymers can be chosen.

In our case we have chosen SBS elastomeric polymers as the most effective range of bitumen modifiers. In terms of effectiveness and cost-performance ratio, they are the products which serve best to perform the task required of them.

They can be used indifferently for SHEATHING and for road ASPHALTS and provide mechanical and elastic features to the material, allowing it to withstand stress and wear beyond the range mentioned above.

They do not break up below 0°C and do not become overly plastic above 50°C, optimally resisting all the normal mechanical stress.

Obviously the extent of the work temperature range of the bitumen depends on the amount of MODIFIER used. But since even costs increase, one needs to reach the proper compromise. Regarding modification of asphalt and sheathing, as we mentioned, there are a great amount of products suitable for the purpose. But in order to be mor e incisive, we will present, in the attachment, only a few of those which are the most representative.

Regarding modification of asphalt and sheathing, as we mentioned, there are a great amount of products suitable for the purpose. But in order to be mor e incisive, we will present, in the attachment, only a few of those which are the most representative.