Do you know what is hot mix asphalt? Asphalt mixture is a composite material, mainly composed of asphalt, coarse aggregate, fine aggregate and filler. Hot mix asphalt is a mixture composed of aggregates, mineral powder and asphalt (165 ± 5 ℃) of different particle sizes in special equipment through manual mixing. The mixing temperature is required to be 150~180 ℃ to help reduce the curing time on the road. It is usually necessary to transport the materials to the construction site with thermal insulation transportation tools for paving and compaction in hot state.
Types of Hot Mix Asphalt
Ordinary Asphalt Mixture
That is, AC asphalt mixture, which is suitable for urban secondary trunk roads, auxiliary roads or sidewalks.
Modified Asphalt Mixture
1.Modified asphalt mixture refers to the asphalt mixture made by adding additives (modifiers) such as rubber, resin, high polymer, ground rubber powder or other fillers to improve the performance of asphalt or asphalt mixture.
2.Compared with AC asphalt mixture, modified asphalt mixture has higher high-temperature rutting resistance, good low-temperature cracking resistance, higher wear resistance and longer service life.
3.The surface course of modified asphalt mixture is applicable to urban expressway and trunk road.
Stone Mastic Asphalt (SMA for short)
SMA mixture is a kind of asphalt mastic binder composed of asphalt, mineral powder and fiber stabilizer, which is filled in the intermittent skeleton.
SMA is a kind of asphalt mixture with discontinuous grading. The proportion of coarse aggregate above 5mm is as high as 70%~80%, and the amount of mineral powder is as high as 7%~13% (the “powder cement ratio” exceeds the limit of the normal value of 1.2); The amount of asphalt is large, up to 6.5%~7%.
SMA is a kind of asphalt pavement mixture with strong deformation resistance and good durability, which is widely used at home and abroad; It is applicable to urban expressway and trunk road.
Modified Stone Mastic Asphalt
1.Modified asphalt is used, and the material proportion is SMA structure.
2.It has very good high temperature rutting resistance, low temperature deformation resistance and water stability, and has large structural depth, good skid resistance, aging resistance and durability.
3.It is applicable to urban expressways and trunk roads with rapid growth of traffic flow and driving frequency, continuous increase of axle load of passenger vehicles, and strict implementation of one-way driving in separate lanes.
Properties of Hot mix Asphalt and Cold Mix Asphalt
At present, hot mix asphalt belongs to the mainstream technology, and the whole construction system is more perfect, but the project implementation energy consumption is large, and the process flow has a great impact on the environment; The mixture of cold mixed asphalt is convenient for storage. Compared with the former, it is more energy-saving and environment-friendly, but its road performance is poor. This may also be one of the reasons why cold mix asphalt pavement projects are relatively “niche”.
The strength, high temperature stability and fatigue resistance of hot mix asphalt mixture are better than those of cold mix asphalt mixture, but the cold mix asphalt mixture is easy to operate and energy-saving, so it is used in the flexible base of low grade pavement or high grade pavement.
The maintenance technology of cold mix asphalt mixture is a major technological revolution in asphalt pavement maintenance. It overcomes the limitations of hot mix asphalt mixture in the process of repairing asphalt pavement due to season, weather and temperature, as well as the environmental pollution caused by asphalt heating at the repair site.
Using Hot Mix Asphalt or Cold Mix Asphalt
The hot mix asphalt and cold mix asphalt have their advantages and disadvantages respectively. Which one you decide to choose depends on your detailed construction project and requirement. After reading this post, if you still have some problems to be solved, you can contact with Luton staff by writing an email or sending messages in whatsup to acquire more information.