Calculate RAP tonnage for aggregate base or determine its cost savings when used in new Hot Mix Asphalt (HMA).
This mode calculates the tonnage of RAP needed to create a compacted base layer.
Example: For a 50ft x 10ft base at 6 inches deep, the compacted volume is 9.26 CY. You must order 10.65 loose CY (9.26 × 1.15), which equates to 12.89 tons (10.65 × 1.21).
This mode calculates the financial benefit of including RAP in a new asphalt mix.
Example: For 1000 tons of HMA with 30% RAP (above the 25% threshold), gross savings are $2,460 (1000 × $0.082 × 30). The processing cost is $900 (1000 × $0.90). Net savings are $1,560.
The Recycled Asphalt (RAP) Calculator is a comprehensive, dual-function tool engineered for professionals in the paving and construction industries. It addresses the two primary applications of Recycled Asphalt Pavement (RAP): as a cost-effective granular aggregate base and as a valuable component in the production of new Hot Mix Asphalt (HMA). By offering two distinct calculation modes, this tool provides precise, context-specific estimates that are essential for project planning, bidding, and sustainable material management. Whether you are building a foundation or designing an asphalt mix, the Recycled Asphalt (RAP) Calculator delivers the accurate figures needed for both structural and financial calculations.
In its first mode (Mode A), the tool functions as a robust aggregate calculator specifically calibrated for RAP. When used as a base material, RAP (often called millings) must be ordered in a loose state but performs its structural function once compacted. The Recycled Asphalt (RAP) Calculator automatically applies a standard 15% compaction factor to the desired final volume and uses an industry-average density for loose RAP aggregate to provide a reliable ordering tonnage. This prevents the common error of under-ordering material and ensures the project has enough RAP to achieve the specified compacted thickness.
The second mode (Mode B) transforms the Recycled Asphalt (RAP) Calculator into a sophisticated financial modeling tool for HMA producers and paving contractors. Incorporating RAP into new asphalt is a cornerstone of sustainable paving, significantly reducing the need for virgin aggregate and expensive asphalt binder. This calculator quantifies the direct cost benefits by applying a linear savings rate for each percentage of RAP included. Crucially, it also incorporates the economic realities of high-RAP mixes. As recognized by federal bodies like the Federal Highway Administration (FHWA), using high percentages of RAP (typically >25%) necessitates additional processing, fractionation, and quality control, which incurs costs. Our calculator models this by applying a conditional surcharge, ensuring the final "Net Cost Savings" figure is both optimistic and realistic. For more on the material itself, Wikipedia provides excellent background information.
By providing this dual functionality, the Recycled Asphalt (RAP) Calculator serves as a complete resource for managing RAP. It bridges the gap between field application and plant production, giving users a single interface for all their RAP-related calculations. This streamlines workflow, improves bidding accuracy, and promotes the cost-effective use of recycled materials, contributing to a more sustainable and economically efficient construction industry.
Explore all remaining calculators in this Material Type category.
Explore specialized calculators for your industry and use case.
As a base, RAP acts as a granular, unbound aggregate, similar to gravel. Its value is in its structural support. In new HMA, the RAP is heated and mixed, and its aged asphalt binder is reactivated, becoming an integral part of the new pavement binder. Its value is in replacing both virgin aggregate and virgin binder.
When using a high percentage of RAP (e.g., >25%), the stiff, aged binder in the RAP can make the final mix brittle. To counteract this, producers must conduct more extensive testing, potentially sort the RAP into different sizes (fractionation), and use special "rejuvenating" agents or softer virgin binders, all of which add cost.
Percentages vary widely by location and application. Low-percentage mixes of 15-25% are very common and require minimal changes to the production process. High-RAP mixes can go up to 40-50% or even higher in some base layers, but these require specialized designs as mentioned above.
Yes, and in many cases, it can be superior. After compaction, the residual asphalt binder on the RAP particles can provide some cohesion, creating a very stable and water-resistant base layer that often outperforms standard granular bases.