ommon Asphalt Pavement Structure

 1. Highway or advanced highway structure

1.1 Pavement Base: it is a kind of layer structure on the subgrade surface, which is used homogenous material to pave layer by layer under certain technical measures, to stabilize the road; common used materials are lime(cement) stabilized soil, lime(cement) stabilized aggregates, lime-flyash stabilized soil or stabilized aggregates.
1.2 Prime Coat: To make better bond of asphalt surface course with the non-asphalt base, the emulsified asphalt, coal pitch, liquid asphalt is pouring on the base to being a thin layer penetrated into the base.
1.3 Seal Coat: it is a asphalt mixture thin layer to close the surface interspace and prevent water from penetrating the surface or the base; The paved up the surface is called upper seal coat, and down the surface is called lower seal coat.
1.3.1 Function: 
    -close the interspace for water-proof;
    -transit and bond effectively between the base and asphalt surface;
    -reinforcement of one surface breakdown or loose;
    -prevent the base damaged by water because of the weather or vehicles before the asphalt paved, if the temporary traffic is required open;
Equipment Exhibition
intelligent road construction equipment
1.3.2 Asphalt surface seal coat( upper seal coat): it is a maintaining layer in the whole road surface by continuous paving method. Main function is to recover or delay the surface asphalt oxidation(aging); reconstruct the antiskid resistance of the pavement; seal the micro or small crack on the surface, to prevent the water penetrating into the structure; prevent the aggregates from falling ,collapsing;
1.3.3 Seal coat types/ methods/use:


Seal coat

Upper seal coat





Vaporific seal coat and reductive seal coat


1.vaporific emulsified asphalt or special reductive sparys on the aging asphalt pavement( the special reductive is required to penetrating into the surface 6cm)


Low traffice flow, slow-speed road and parking lots

Chips seal coat

2.spry the asphalt material(heated asphalt, light asphalt, emulsified asphalt)  on the surface, then distribute the sand, chips or proper aggregates and then rolling compaction

It is a easily construction method with low cost.

Slurry seal(micro surfacing)


3.It is a slurry mixture of emulsified asphalt, broken aggregates, mineral powder, water and additive. Distribute to the original asphalt pavement to be a even maintaining layer, which is joint  firmly with the original road, antiwear surface structure.


It is used to the large traffic flow and high-speed way.

Lower seal coat


Chips seal


Same as Item.2

Used between the base and surface course

Slurry seal(micro surfacing)

Same as Item.3

Same as the above