<p><p><figure id='attachment_2616' style='max-width:476px' class='caption aligncenter'><img class="wp-image-2616 size-full" src="https://www.geoinstitute.org/sites/default/files/geotech-tools-uploads/…; alt="Photograph of equipment used for rubblization of pavement, a RMI resonant breaker." width="476" height="288" /><figcaption class='caption-text'> Rubblization using RMI Resonant Breaker (Photograph courtesy of Resonant Machines, Inc. 2005)</figcaption></figure><h2>Basic Function:</h2>Onsite Use of Recycled Pavement Materials is the reuse of asphalt or concrete pavement in the construction of new pavements, rehabilitation of existing pavements, and construction of embankments.<br><h2>Advantages:<em> </em></h2><ul> <li>Cold Planning (CP) improves pavement and removes wheel ruts and washboarding</li> <li>Hot Recycling (HR) conserves non-renewable resources and conserves energy</li> <li>Reduces the cost of disposing waste</li> <li>Can reduce pavement reconstruction cost</li> <li>Environmental and economically beneficial</li></ul><h2>General Description:</h2>Onsite use of recycled pavement materials is the reuse of Reclaimed Asphalt Pavement (RAP), Concrete Pavement (RCP), and unbound, cement-treated base and subbase materials through stabilization, remixing, or re-cementing in the construction of new pavements, rehabilitation of existing pavements, and construction of embankments.<br><h2>Geologic Applicability:</h2><ul> <li>Subgrade consists of highly plastic organic clay (CH) or silt (MH), clayey sand (SC), or silty sand (SM).</li> <li>Hauled shredded waste tires can be combined with sand and other granular soils up to 40% by volume of the embankment fill.</li> <li>Recycled concrete aggregate may include 10 to 30% of the subbase and asphalt from the shoulder or composite pavement.</li></ul><h2>Construction Methods:</h2>The existing asphalt or cement layer can be removed by milling or full depth removal. This removed layer can be used as unbound aggregates or combined with cement or asphalt treatment. It is often rubblized onsite to be used as a base for new asphalt or concrete and is usually 2 to 4 inches (50 to 100 mm) in depth. Materials that can be reused include RAP, RCP, and unbound, cement-treated and asphalt-treated base and subbase materials. This can be used in stabilization, remixing or re-cementing in the construction of new pavements, rehabilitation of existing pavements, and construction of embankments.<br><h2>Additional Information:</h2>Using recycled pavement, rehabilitation of existing pavement and widening at the same time can reduce construction time and cost. The properties of the construction formed asphalt layer are dependent on the existing recycled materials and the size and type of equipment used for the demolition. This technology is considered to be environmentally and economically beneficial by reducing the mining of aggregates. Research is needed on long-term performance of the recycled materials.<br><h2>SHRP2 Applications:</h2><ul> <li>Embankment and roadway construction over unstable soils</li> <li>Roadway and embankment widening</li> <li>Stabilization of pavement working platforms</li></ul><h2>Example Successful Applications:</h2><ul> <li>Cold In-place Recycling of Pavement Material, Waseca, MN</li> <li>Full Depth Reclamation, Amarillo, TX</li> <li>Hot in-place recycling, Orange County, FL</li></ul><h2>Complementary Technologies:</h2>Plant produced RAP-HMA mixes for paving; chemical &amp; mechanical stabilization; hot mix asphalt paving with waste materials (including recycled pavement materials)<br><h2>Alternate Technologies:</h2>Rehabilitation alternatives; blending cement with lime, fly ash, and/or slag; cold in-place recycling; hot mix asphalt layer over existing pavement.<br><h2>Potential Disadvantages:</h2><ul> <li>Ability of rehabilitation technique to correct a pavement distress dependent on type of pavement distress.</li> <li>Increased crack susceptibility</li> <li>Material is less uniform than in-plant mixing.</li> <li>Product variability and low resilient moduli sometimes limits Reclaimed Asphalt Pavement (RAP) applications.</li> <li>Technical maturity and long term performance are concerns of recycling pavement.</li></ul><h2>Key References for this technology:</h2>Asphalt Recycling and Reclaiming Association (ARRA) (2001). Basic asphalt recycling manual, US DoT, FHWA, USA.</p><p>FHWA (1993). A Study of the Use of Recycled Paving Material- Report to Congress. FHWA-RD-93-147, EPA/600/R-93/095.</p><p>Sullivan, J. (1996). Pavement Recycling: Executive Summary and Report, Rep. No. FHWA-SA-95-060.</p></p>