Basic Concept:
The Basic Idea in building a road for all weather use by vehicles is to prepare the sub-grade or foundation, provide necessary drainage, and construct a pavement that will:
- Have a sufficient total thickness and internal strength to carry expected traffic loads,
- Prevent the penetration or internal accumulation of moisture, and
- Have a top surface that is smooth, skid resistant, and resistant to wear, distortion, and deterioration by weather.
Asphalt pavement is a general term applied to any pavement that has a surface constructed with asphalt. Normally, it consists of a surface course (layer) of mineral aggregate coated and cemented with asphalt; and one or more supporting courses, which may be of the following type:
- Asphalt Base course, consisting of asphalt aggregate mixtures
- Crushed Miscellaneous Base or Process Miscellaneous Base
- Portland Cement Concrete.
• (Citation) Asphalt Technology And Construction Practices
Resurfacing Process:
Step 1. Cold Milling (Overlay)
The existing wearing surface shall be cold milled (profiled) to establish uniformly grooved ridges that are neat and uniformed to remove irregularities in the pavement to improve ride ability.
Step 2. Full-depth Milling (Reconstruction)
Full depth milling is the removal of all asphalt materials from the existing roadway down to the base and sub-base. These materials are replaced with new aggregates base materials and asphalt.
Step 3. Asphalt Concrete Pavements (Paving)
Asphalt Concrete Pavements shall be placed in one or more courses of a prepared road bed, base or existing pavement. The roadbed shall be motor swept clean of all dust, debris or other loose materials.
Step 4. Tack Coat
A tack coat of emulsified asphalt shall be uniformly applied to the roadbed to act as binder for the newly applied asphalt material.
Step 5. Paving
The asphalt concrete shall be evenly spread upon the sub-grade at a predetermined depth to accommodate traffic loads at temperatures ranging from 270 degrees Fahrenheit to 320 degrees Fahrenheit.
Step 6. Compaction
The asphalt concrete shall be thoroughly compacted by steel tandem drum rollers to achieve 95% compaction for the new mat. Successful compaction prevents water penetration into the asphalt which can cause premature aging and oxidation of the roadway.
Step 7. Striping
Once the new asphalt mat has cooled down sufficiently below 180 degrees Fahrenheit, the rolling operations are completed once all marks have been removed. The roadway can then be opened fully to traffic.