THE’asphalta mixture of bitumen and compounds like sand, gravel and stoneit is commonly used for the flooring of the roads thanks to its durability, versatility and ability to resist the stresses of vehicles and the weather conditions. There are different types of asphalt used according to the specific needs of the road and local conditions. From the bituminous asphalt, to the recycled one, to the high porosity. Here is an overview of the main types of asphalt used on the streets, with their advantages and disadvantages.
Bituminous asphalt (conventional asphalt)
First of all the asphalt, or more precisely bitmonous conglomerate, is a material used for floor roads, highways and squares. Is mainly composed of bitumena viscose substance derived from oil, which is mixed with sand, gravel and stone. This mix is heated at high temperatures until it becomes a thick pasta that can be easily spread on the road surface. Once the asphalt cools down, it forms a solid and resistant surface.
The bituminous asphalt is the most common type of asphalt, which is used in the vast majority of cases when there is a road to pave. It is produced by mixing the bitumen together with the sand and aggregates of different granulometry. It is mainly used for the construction of urban roads, Autostrade and low roads and medium intensity of traffic. It is very flexible and resists quite well to thermal changes, even if the latter still involve some effects, which we will see later.
The main advantages are those relating to good resistance to stresses, deriving from traffic, to durability, at the relatively low cost and to the fact that the bituminous asphalt can be restored, that is, able to be repaired and restored in case of damage.
Among the disadvantages we can include the need for a relatively frequent maintenance, as if not adequately maintained with targeted interventions, the bituminous asphalt can wear out quickly enoughand not least theCo emission2 in the environment as a consequence of bitumen production.
Draining asphalt (porous)
This type of asphalt is designed to allow the passage of water through the flooring, reducing the risk of flooding. It is composed of a mixture of aggregates with empty spaces between themwhich allow the water to easily filter through the surface. It is mainly used in areas subject to strong rains or in urban areas where you want to improve rainwater management.
Among the main advantages we find, as the name already says, the ability to “manage” and therefore drain rainwater, reducing the need for use of more or less complex drainage systems. The surface that is created with the use of draining asphalt is a non -slip surface; The draining asphalt offers a better adherence Compared to other types of asphalt, especially in rain conditions. Last but not least, we also have a good level of noise reduction Compared to traditional asphalted surfaces.
Among the disadvantages we find the higher costin fact, the construction of road flooring with the use of draining asphalt involves an increase in costs. The accumulation of debris in the spaces between the inert can represent a further disadvantage; The risk is that obstruction of the spaces through which the water is drained.
Modified asphalt with polymers (PMA)
The modified asphalt with polymers (PMA) is a traditional asphalt to which they are added polymers to improve its performance. The addition of polymers improves the physical properties of the asphalt, such as its elasticity, resistance and durability. This type of asphalt is particularly suitable for roads with high intensity of traffic or for particularly severe environmental conditions.
Among the advantages we find one greater durability and resistancewith a consequent greater resistance to deformation and cracking. The performance in extreme climatic conditions (hot or cold) In fact, the modified asphalt with the polymers is resistant to both heat and coldwithout compromising performance. In addition, the modified asphalt with polymers ages better than the traditional asphalt.
Among the disadvantages we find i costs High use, in fact, the production and application of modified asphalt with polymers is more expensive than the conventional asphalt.
Recycled asphalt (rap – complaint asphalt pavement)
This type of asphalt uses Recycled material from existing road flooring. It is obtained by removing the old pavement and treating it to be reused. The recycled asphalt is mixed with new materials to obtain an asphalt that respects the required quality standards. It is an ecological choice that reduces the demand for new materials.
One of the most important advantages of this material is the sustainability, In fact, recycled asphalt reduces the amount of waste and the consumption of natural resources. We then have the advantage of the reduced cost of the material, compared to the other types of asphalt which certainly require higher costs. In addition, the production of this type of asphalt requires a less use of energy.
The disadvantages concern instead Quality standards of the material that cannot always be guaranteed, especially with respect to the origin of the same. Another disadvantage is that of lower durability of the material, which, compared to the new asphalt, can have a life and effectiveness reduced over time. Furthermore It is not suitable for all types of infrastructures Stradai, and therefore this reduces the areas of use.
High porosity draining asphalt (HMA)
The high porosity draining asphalt is an advanced variant of the draining asphalt, designed to guarantee a better rainwater management and improve road safety. Is made with a mixture of bigger aggregates and with one wider empty space Compared to the traditional drainage asphalt.
Among the advantages we undoubtedly have a Improvement of the drainage of rainwaterwith a prevention of risks for traffic and reduction of flooding. It is also able to absorb less heatand therefore guarantees a better response in behavior in extreme climatic conditions.
Among the disadvantages, here too, we find i high costs of use, and the need for a frequent maintenance; The high porosity draining asphalt can be subject to obstruction by debris, needing more attentive monitoring and maintenance.
