# Cold Plant Mix Recycling

Cold plant mix recycling, the less common of the two cold recycling methods, involves mixing RAP with an asphalt emulsion or foamed asphalt at a central or mobile plant facility.

- Canonical URL: https://pavementinteractive.org/reference-desk/pavement-types-and-history/pavement-types/cold-plant-mix-recycling/
- Last updated: 2018-09-17
- Review: reviewed by licensed professional engineers on the previous Pavement Interactive site, where reviewers were not recorded by name

AAPTP Project 05-01

Cold plant mix recycling, the less common of the two cold recycling methods, involves mixing RAP with an [asphalt emulsion](https://pavementinteractive.org/reference-desk/materials/asphalt/emulsified-asphalt/) or [foamed asphalt](https://pavementinteractive.org/reference-desk/materials/asphalt/foamed-asphalt/) at a central or mobile plant facility. A [rejuvenating agent](https://pavementinteractive.org/reference-desk/maintenance-and-rehabilitation/maintenance/rejuvenators/) can be added to improve the recycled [asphalt binder](https://pavementinteractive.org/glossary/asphalt-binder/) viscosity and new aggregate can also be added to improve overall performance. The resulting cold mix is then typically used as a stabilized [base course](https://pavementinteractive.org/glossary/base-course/).

## Purpose

Stabilized base course

## Materials

RAP, [asphalt emulsion](https://pavementinteractive.org/glossary/asphalt-emulsion/) or foamed asphalt, asphalt [rejuvenating agent](https://pavementinteractive.org/reference-desk/maintenance-and-rehabilitation/maintenance/rejuvenators/) and possibly virgin aggregate.

## Mix Design

No generally accepted mix design method, but the Asphalt Institute recommends and most agencies use a variation of the [Marshall mix design method](https://pavementinteractive.org/reference-desk/design/mix-design/marshall-mix-design/) (FHWA, 2001b[^1]).

## Other Information

Since cold in-place recycling has become more commonplace, cold plant mixing has become less popular.

## Sources

[^1]: Federal Highway Administration (2001b). Reclaimed Asphalt Pavement User Guideline: Asphalt Concrete (Cold Recycling). Web page on the Turner-Fairbanks Highway Research Center web site. Accessed 16 October 2001. https://web.archive.org/web/20150405042130/http://www.tfhrc.gov/hnr20/recycle/waste/rap131.htm