Asphalt pavement refers to the various types of pavement which is paved with mineral materials mixed with road asphalt materials. Asphalt binder improves the ability of granular materials to resist the damage caused by driving and natural factors, and makes the pavement flat, less dust, impermeable and durable.
Asphalt pavement is one of the most widely used high-grade pavement in road construction. The asphalt structure layer of asphalt pavement itself belongs to the range of flexible pavement, but its base course can also use rigid cement concrete or semi-rigid hydraulic material in addition to flexible material. According to different properties, asphalt pavement has many hot types.
8 Types of Hot Asphalt Pavement
Porous Asphalt Pavement
Compared with the ordinary asphalt pavement, the porosity of porous asphalt pavement is 15% – 20%, even more than 20%, while the porosity of ordinary asphalt pavement is only 3% – 6%.
Due to the large porosity, rainwater can penetrate into the road surface and drain away from the connected pores to the edge of the road surface. So porous asphalt pavement is also called drainage asphalt pavement.
Hot Mix Asphalt Pavement
Hot mix asphalt pavement is a kind of asphalt pavement that is heated and mixed by artificial aggregate and asphalt in special equipment, transported to the construction site by heat preservation transportation means, and paved and compacted in hot state.
Generally, the heating equipment needs to provide a working temperature of 150-290℃.
Warm Mix Asphalt Pavement
Warm mix asphalt pavement is to use warm mix asphalt technology to produce warm mix asphalt mixture and lay highway pavement.
Compared with the same type of hot mix asphalt mixture, warm mix asphalt mixture can reduce the mixing temperature of the asphalt mixture by more than 30 – 40 ℃ through technical means on the premise of basically not changing the asphalt mixture proportion and construction technology, and its performance can reach the new type of hot mix asphalt mixture.
Cold Mix Asphalt Pavement
Cold mix asphalt mixture is a kind of mixture formed by mixing unheated ore (aggregate) and diluted asphalt. It is suitable for any weather and environment. Cold mix asphalt mixture is suitable for a wide range of ambient temperature, which can be used between – 20℃ and 50℃.
The use of cold mix asphalt mixture can repair the pavement in time, keep the pavement fresh, ensure the pavement smooth, reduce the number of pavement repair, and extend the road life.
Quiet Asphalt Pavement
Quiet asphalt pavement is one of the main measures to reduce highway noise. Quiet asphalt pavement is full of pores, the principle of porous sound absorption is used to achieve noise reduction, so porosity is the primary factor affecting the acoustic performance of quiet asphalt pavement.
The quiet asphalt pavement is located on the surface of the highway, which is a porous structure made of large pore asphalt concrete. It can reduce the noise by 5 dB to 8 dB.
Coal Asphalt Pavement
Coal asphalt is a byproduct of coking or gas production. The volatiles from the carbonization of bituminous coal are condensed into coal tar. The residue after the extraction of various oil products by coal tar fractionation is coal asphalt.
Coal asphalt has good anti-corrosion ability and cohesiveness, especially suitable for pavement, parking lot and so on.
Petroleum Asphalt pavement
In petroleum asphalt pavement, petroleum asphalt is mainly used as cementitious material, which is used to prepare asphalt concrete, asphalt mortar and other asphalt mixture together with mineral materials such as crushed stone and sand.
The petroleum asphalt pavement has good stability, plasticity and high safety factor.
Colored Asphalt Pavement
Colored asphalt pavement refers to the mixture of decolorized asphalt and various color stones, color materials, additives and other materials at a specific temperature, which can be prepared into a variety of colored asphalt mixture, which is then paved and rolled to form a colored asphalt concrete pavement with certain strength and road performance. Also known as color asphalt pavement.
Colored asphalt pavement is not only convenient for traffic management, but also has good road performance. Under the action of different temperature and external environment, its temperature stability, water damage resistance and durability are very good, and it does not deform, and has good adhesion with the base.
Main Features of Asphalt Pavement
Asphalt pavement is usually used to pave the surface layer of highway, which is directly affected by vehicle load and atmospheric factors. At the same time, the physical and mechanical properties of asphalt mixture are greatly affected by climatic factors and time factors, Therefore, asphalt pavement must have the following important features:
1. High Temperature Stability
High temperature stability is the ability of asphalt pavement to resist flow and deformation. As the strength and rigidity of asphalt pavement decrease significantly with the increase of temperature.
in order to ensure that the asphalt pavement will not produce waves, displacements and ruts under repeated driving loads in high temperature season, the asphalt pavement should have good high temperature stability.
2. Low Temperature Crack Resistance
Low temperature crack resistance refers to the ability of asphalt pavement to resist low temperature shrinkage cracks. As the temperature of asphalt pavement decreases, the stiffness increases, and the expansion capacity decreases.
Under the action of external load, part of the stress is too late to relax, and the stress gradually accumulates. When the accumulated stress exceeds the tensile strength of the material, it will crack, which will lead to the damage of the pavement.
3. Water Stability
Water stability refers to the ability of asphalt pavement to resist the erosion of water and gradually produce asphalt membrane peeling, dropping, loosening, pit and groove damage.
This is due to the existence of water, on the one hand, it reduces the cohesion of asphalt itself, and on the other hand, it also destroys the cohesion between asphalt and mineral aggregate in asphalt pavement, thus accelerating the occurrence of peeling off and causing water damage to the road.
4. Fatigue Resistance
Fatigue resistance refers to the ability of asphalt pavement to resist damage under repeated load. It is due to the repeated action of wheel load during the use of asphalt pavement, which is in the state of stress-strain overlapping change for a long time, resulting in the gradual decline of pavement structure strength.