In order to ensure that the surface layer after micro-surfacing construction can still achieve a long service life under heavy traffic loads, ensure the extremely high adhesion between asphalt and stone and the excellent wear resistance of the micro-surfacing surface, This process has extremely high requirements on materials.
1. The stone is required to be strong, wear-resistant and clean. The gradation of stone is usually medium-grained or coarse-grained (JTJ E32/ES3), and the thickness after molding is generally about 5mm or 10mm.
2. The emulsified asphalt used for micro-surfacing must be polymer-modified, usually SBR latex, or SBS-modified, whose residue has a higher softening point. The requirements are different internationally, but generally the requirements of ISSA are adopted, which is not less than 57℃.
3. The design of the micro-surfacing mixture adds a 6-day abrasion test and rolling sand sticking test (LWT) to the slurry seal to evaluate its water damage resistance and maximum asphalt dosage. Foreign surveys show that the service life of microsurfacing is generally 5 to 6 years, and can reach 8 years.
4. When used to fill ruts, a rolling deformation test is also required. In addition, the whetstone ratio of the micro-surfacing mixture can be determined using the Marshall method or the Wihm method.
5. Requirements for construction pavement: If there are diseases on the construction pavement, they must be dealt with before micro-surface construction can be carried out.
6. The use of micro-surfacing can implement single-layer or double-layer paving according to the road conditions: Under normal circumstances, if there are many heavy vehicles and heavy traffic, the paving thickness is about 10mm; for medium traffic volume, the paving thickness is about 7mm; Small and heavy vehicles only need to pave 3-4mm thick.