Milled AsphaltThe SMART PAVE System Process

The Smart Pave System utilizes the existing milled asphalt known as RAP from highways and roads prior to repaving operations.  The RAP can either originate from a known single source or from multiple sources.

Step One

Asphalt ComponentsThe reclaimed asphalt pavement (RAP) is analyzed for composition qualities including binder and gradations.
           
The binder is analyzed for PG properties. Regional Properties may be used in this analysis. Generally, a very small percentage of rejuvenator agent is introduced to adjust the binder to the desired PG grade.  This also provides full replenishment of any oxidized asphaltenes, returning the asphalt cement to its original characteristics. This is usually about .5% (1/2 of 1%) of the HMA produced.

If the existing milled composition comes from a known source and meets specification gradation requirements “as is”, no further RAP pre-processing is necessary. Steps Two and Three would not be required and Step Four would be next - heating the material.

RAP StockpilesStep Two

If the RAP comes from varied sources, the RAP stockpile is screened and "fractionated" to return the RAP to original gradations.  The various gradated RAP products are then fed into their respective cold feed bins.

Metering SystemStep Three

Depending on gradation analysis, the feed bins will introduce the gradated RAP at the correct feed rate. If due to specification gradations, any virgin aggregates adjustment is needed, the virgin aggregates are introduced along with the gradated RAP in the correct proportion via a multi-bin metered cold feed system.

RAP ProcessorStep Four

An indirectly heated (specifically designed for 100% RAP) drum plant processor is used for full heating of 100% recycled asphalt or any recycled-virgin blend mix.

Silo StorageStep Five

Once material processing has been completed, the fully heated recycled HMA is conveyed into silo storage, awaiting discharge into trucks for transport to the jobsite.

Hot Mix AsphaltStep Six

At the jobsite, the recycled hot-mix asphalt is transferred to the roadway by the pavement lay down crew. The 100% recycled asphalt pavement actually results in "equal to or better" quality and performance than HMA made from new virgin materials and is handled in the same manner.

A key part of the Smart Pave System is RAP stockpile discipline. Control of your RAP source and inventory will pay for itself many times over. A properly worked RAP stockpile along with screening/fractionating will create a very uniform composite mix, usually more consistent than virgin material from a quarry. Screening of RAP may be necessary to eliminate unwanted tramp material, but crushing should be avoided if possible as a) it may add substantial unnecessary cost, and b) it creates added fines to the mix an undesirable attribute that may actually place your valuable RAP out of specification bands. Generally speaking, RAP milled from highways and roadways with upward cut milling heads will generally stay within 10% of original specifications.