<p><p><h2>Commentary</h2>Recycled pavement materials are typically incorporated into a highway reconstruction project in one of the following ways:<br><ul> <li>Aggregate component of pavement</li> <li>Aggregate component of subbase/base course(s)</li> <li>Granular shoulder material adjacent to the paved roadway</li> <li>Embankment materials</li></ul>Because recycled materials are components of a contract pay item, the associated cost of recycling is difficult to discern from historical bid tabulations.</p><p>As a rule, onsite incorporation of recycled pavement materials will almost always result in a cost savings that is passed on to the owner. There are, however, two exceptions to this rule which may occur independently or in combination:<br><ul> <li>Projects that are located in close proximity to virgin aggregate sources. In this case, where the cost of hauling virgin aggregates may be less than the cost of hauling onsite materials, cost savings associated with onsite recycling may be negligible.</li> <li>Forcing a contractor to utilize recycled pavement materials onsite when an external market exists and alternative materials are available at a lower cost. An example of this would be, specifying that recycled materials must be incorporated into an embankment when a borrow source is readily available and the recycled material can be sold on the open market. In this case, the owner misses out on a potential cost savings. Competitive market forces from the low bid system used on most highway projects will dictate that cost savings associated with recycling pavement materials is passed on to the owner, regardless of where the recycled materials are incorporated.</li></ul>In general, specifications should allow the use of recycled materials, but not force their use. This allows market forces to determine the most cost effective and sustainable use of recycled materials. Both the availability of alternative materials and the demand from other markets for recycled materials have a large influence on project costs savings that are passed on to the owner and make them difficult to quantify. Except for very large projects where the potential cost savings may be significant (greater than 100,000 tons of available recycled material), preliminary project budgets should include a nominal cost savings of $2.00 to $5.00 per ton of recycled material that is incorporated onsite.<br><h2>Cost Information Summary</h2>The following table provides general cost information on recycling methods used in highway construction. Cost ranges are based on input from an anonymous recycling contractor who works in the Midwest and Southwest regions of the US; representative costs from state highway agency bid tabulations are used where applicable.</p><p><table class='tablepress' id='tablepress-113'><thead><th>Recycle Application</th><th>Cost Information</th><th>Factors Which May Potentially Impact Costs</th></thead><tbody><tr><td >Rubblization</td><td >MI, NE and NY bid tabulations from 2008 through 2010 show average unit cost ranges from $1.70 to $2.22 per SY (projects greater than 20,000 SY</td><td >Existing pavement thickness
Existing reinforcement
Base, subbase and subgrade support
Number of mobilizations required to complete rubblization
</td></tr><tr><td >Cracking and Seating</td><td >MI, NE and NY bid tabulations from 2008 through 2010 show average unit cost ranges from $0.19 to $0.99 per SY (projects greater than 20,000 SY)</td><td >Existing pavement thickness
Existing reinforcement
Base, subbase and subgrade support
Number of mobilizations required to complete cracking and seating
</td></tr><tr><td >Recycled pavement used as a replacement aggregate in any pavement, base and/or subbase layer</td><td >The cost difference between recycled and virgin aggregate is highly variable and should be conservatively estimated based upon local conditions
Crushing concrete pavement costs approximately $7.00 to $10.00 per ton (circa 2010)
</td><td >Cost savings are highly sensitive to the prevailing market price of virgin aggregate, of which freight may be a significant factor
Hardness and abrasiveness of aggregates in the pavement to be recycled – production rates are reduced and wear items are replaced more frequently
Steel reinforced pavements cost more to recycle
Multiple mobilizations of crushing and screening equipment can add significant costs
</td></tr><tr><td >Full depth reclamation </td><td >Processing an existing 6” thick pavement is approximately $3.00 per SY
Cost of binder materials should be determined from local bid tabulations
</td><td >Cost will increase as reclamation depth increases
Local availability of binder materials should be considered (supply and freight costs)
</td></tr><tr><td >Embankment material</td><td >Existing pavement materials should not be used as embankment, unless the only alternative is disposal in a landfill</td><td >Market forces dictate that revenues associated with selling recycled materials off a project are used to offset costs to the owner (contract costs are reduced)</td></tr></tbody></table><h2>Conceptual Cost Estimating Tool</h2>No cost estimating tool is provided for this technology. The potential uses of recycled pavement materials are too many and too varied to provide a simplified tool. Preliminary project cost savings should be estimated by calculating the difference between recycled materials and alternative materials.</p></p>