Section 10: Alternate Pavement Rehabilitation Options
Alternate pavement rehabilitation options are used to allow more competition on pavement rehabilitation projects when using specialty processes.
This section will provide information on alternate pavement rehabilitation options to:
- Anchor: #GCFAFIKT
- hot in-place recycling (HIR), Anchor: #TYOIBSKY
- thin bonded friction courses (PFC or wearing), Anchor: #HJVJKLEB
- reflective crack relief interlayer (RCRI).
10.1 Alternate Options to Hot In-place Recycling
The purpose of hot in-place recycling (HIR) is to correct asphalt pavement surface distress, such as surface cracking, roughness, or lack of skid resistance, through recycling the existing pavement surface. HIR can be effective in correcting surface defects, as long as the defects are not caused by structural inadequacy of the pavement.
The Cutler HIR process involves recycling the existing asphalt surface layer by heating, scarifying, and adding a recycling agent. The recycled material is placed on the roadway surface, a thin overlay of new hot-mix is placed over the recycled layer, and the entire pavement layer is compacted using conventional compaction equipment.
Alternate options are mill and overlay or surface recycling process, also referred to as the Dustrol process. Mill and overlay involves milling 1 in. of the existing top layer and replacing it with 2 in. of new overlay. RAP content in accordance with Item 340 should be allowed in the new 2-in. overlay.
The Dustrol process is an alternate to the Cutler process. The Dustrol process is a surface recycling process. The Dustrol process involves heating and scarifying the top layer of asphaltic pavement (typically, the top 1 in.), mixing a recycling agent. A new overlay is placed on top of the new recycled surface using standard paving operations.
Anchor: #i100802610.2 Alternate Options to Thin Bonded Friction Course
The thin bonded friction course is used as a pavement preservation treatment to restore skid resistance, improve ride quality, and arrest surface oxidation.
The thin bonded friction course is an open-graded mix (PFC or denser wearing course) placed on polymer modified rapid-setting emulsion membrane. Placement of a thin bonded PFC surface is intended to provide increased safety and better ride quality on a high speed roadway. These mixtures are placed before the emulsion breaks using a specialty paver. Note: Membrane rate must meet the requirements of Item 348.
The thin bonded friction course may also be used when there are restrictions on overlay thickness due to clearance requirements.
The alternate option to this process is placing a tack coat and thin overlay using a mixture such as a Thin Overlay Mix (TOM, Item 347), dense-graded TY F mix (Item 341), or an underseal (seal coat) plus a 3/4-in. thick PFC (Item 342). These options require two separate operations/pieces of equipment.
Anchor: #i100809210.3 Alternate Options to Reflection Crack Relief Interlayer (RCRI)
The purpose of the reflection crack relief interlayer (RCRI) is to retard reflection cracks on asphalt concrete overlays located on top of jointed concrete pavements.
The RCRI is a fine mix that is designed for cracking resistance using the flexural beam fatigue test. The mix is typically placed 1-in. thick and should be covered with an adequate overlay thickness to provide adequate resistance to rutting.
An alternate option is the crack attenuating mix (CAM). The cracking resistance of the CAM will be evaluated using the overlay tester.