5 Surprising Items That Can’t Be Recycled
Cold recycling of asphalt concrete is a method of recycling asphalt that has been available for decades. An innovative application of this technique involves constructing a small temporary plant onsite and removing, reprocessing and relaying the asphalt all at the same location. This technique is knows as Cold Central Plant recycling. However, sometimes the plant is constructed near the site if the area to be paved will not support a plant. This option involves trucking to and from the site, with the associated environmental impact and cost. The more technically specific name of Cold On-Site Recycling refers to the situation where a plant can be constructed onsite. This article enumerates the benefits of Cold On-Site Recycling over other traditional paving options. Cheapest Skips in Derry
SIGNIFICANTLY REDUCES COSTS
1. Experience has shown that the cost of Cold On-Site Recycling is less expensive than conventional paving methods.
2. For starters, all or most of the needed material is in place, so the total cost of new asphalt is noticeably less. Often, the only necessary new material purchase is the hot-mix asphalt cap.
3. Because material is being recycled onsite, many fewer truck hauls are required.
4. There are no dump fees for the recycled asphalt concrete.
5. Labor costs are significantly reduced because of the shorter duration of the project.
In August of 2008 Cold On-Site Recycling was used to repave a portion of the Vintage Faire Mall in Modesto, CA. The estimated cost to pave this mall using traditional milling and surfacing was $1.8 million. The job cost using Cold On-Site Recycling was $1.2 million, for an actual cost savings of $600,000.
POTENTIALLY SHORTER DOWNTIME
The Cold On-Site Recycling process removes only the top 2 to 4 inches of asphalt concrete. Traditional remove and replace methods take not only the asphalt layer, but the rock and potentially some of the soil layers and replaces them. Because this is not necessary, assuming the subgrade is in good condition, it is not necessary to take the time (and spend the money) to replace the rock and prepare the soil, resulting in much shorter downtimes. Another advantage to both Cold On-Site and Cold Central-Plant Recycling methods is that if there are subgrade issues the asphalt pavement can still be stripped off and saved on site. Then, failed areas of the base section can be repaired prior to recycling and placing the salvaged asphalt concrete.
AS DURABLE AS TRADITIONAL SURFACING METHODS
A concern often raised with recycling is the quality of the recycled product; Cold Recycled Asphalt has different properties than “virgin” hot mix. On a structural basis, CALTRANS assigns Cold Recycled Asphalt a “Gravel Equivalency Factor’ of 1.7, while for most Hot Mix Asphalts (“HMA”) the Gravel Factor is 2.0. In the field this often translates into a slightly thicker section when using cold recycled asphalt. For example, if the design calls for 4″ AC section and the Owner wants to substitute cold recycled asphalt for part of the section, then a typical substitution is 3″ of the cold recycled asphalt over-laid by 1.5′ of HMA. The resulting 4.5″ section is structurally equivalent to 4″ of HMA. But, because the processing of the cold recycled asphalt has a different internal structure, and the new section is a two-layer system, the pavement is more resistant to thermal and reflective cracking.