Polymer-modified asphalt seals the deal for New York state

Asphalt Case Studies
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New York Rte. 219 in Western New York is a 65 mph limited-access four-lane divided highway. Within the last few years, the composite pavement was milled and resurfaced.  However, recent reflective cracking over the transverse and longitudinal joints has created a maintenance problem for the New York State Department of Transportation (NYSDOT).  The traditional method of milling the asphalt 18 in. wide to the portland cement concrete (PCC) pavement and filling with hot mix asphalt (HMA) has proven to be slow and costly.  Because of the nature of the repair, compaction of the HMA is difficult to achieve and the expected results of the repairs using hot mix asphalt are marginal.

 

Pavement maintenance engineers for the Rte. 219 project heard about a repair alternative to HMA from a maintenance engineer from Long Island, N.Y., who has used the material, Crafco PolyPatch, successfully for several years.  PolyPatch is a polymer-modified asphalt that is prepackaged with a select aggregate and provides a flexible, load-bearing, waterproof, highly adhesive repair to both asphalt and concrete pavement.

 

As PolyPatch seemed ideal for use in repair of large cracks, NYSDOT agreed in September 2011 to an evaluation installation of the product on Rte. 219.  The pavement was prepared by cleaning and drying using a hot air lance while the material was heated and mixed using a Crafco Patcher II melter. PolyPatch was then applied at 380 degrees Fahrenheit using an application cart, which provided a neat 6-in. wide overband. 

 

The material is self-leveling and fills all voids to provide a solid repair that does not require compaction.  The flexibility of the material allows it to accommodate the expansion and contraction of the pavement and reduces the stress on the repair and surrounding pavement, allowing it to perform better than a more rigid HMA.  Additionally, PolyPatch and its highly adhesive bond will waterproof the repair, preventing water intrusion to the sub-base, which extends the life of the repair and pavement.  Compared with repairs using hot mix asphalt, PolyPatch proved to be much quicker and required less equipment and fewer personnel on site, resulting in reduced project costs and less inconvenience to the traveling public, in addition to the improved performance of the material.

 

The engineers are also considering a 1-in.-deep x 8 in.-wide milled reservoir configuration to evaluate PolyPatch’s performance as a recessed application, in addition to the overband installation.

 

 

Overlay Init