January 20, 2019

Porous Asphalt Enters the Mix

It sounds impossible: pavement tough enough to drive on that lets water drain right through it (picture a parking lot in a downpour without any standing water anywhere).

But such pavement does exist and it’s actually not new. For some time now O&G has fielded inquiries for porous asphalt (technically “pervious asphalt”). With new federal and state regulations in play, many municipalities are requiring porous pavements. The number of calls that Brad Oneglia, Assistant Vice President, Asphalt Division, receives for the product has been climbing steadily, prompting him to add porous asphalt to the company’s offerings.

The primary reason porous asphalt is rising in popularity and being written into specifications? Because pervious pavement allows storm-water to drain through into the stone subbase it sits on and then down through the soils and into aquifers, eliminating any additional intake into the local storm water system.

As of today, though, just how to make it remains open to interpretation. There are no specifications for pervious pavements in Form 816, the go-to Connecticut DOT specifications handbook,  considered by many to be the Bible for preparing asphalt mixes for Connecticut roads. “So with some investment and the work of Leighton Davis who was central to making various formulations,” says Oneglia, “we developed a mix design we can put our name to. Then through  the diligence and hard work of our plant operators and field staff that mix design is turned into reality for our customers.” Regular testing ensures that pervious asphalt meets design specs and protects paving company clients and end  users.

Making porous asphalt is a more particular operation than making the other asphalt mixes turned out at the company’s seven plants. The mix cannot contain many of the aggregates or other components commonly used in asphalts. To prevent contamination, plants work around their normal schedules to make porous product whenever customers need it (prior notice is required). Typically it’s either first thing in the morning, late in the day or on a weekend to ensure that the mix meets O&G performance specs.

Porous asphalt is an environmentally responsible product and well suited to the sustainable building industry. It’s right in line with other green initiatives at the company, like recycling asphalt milled off roadways, or turning concrete and asphalt demolition into subbase for paving, or pouring large retaining blocks made from waste concrete, or repurposing stone scraps generated in the Masonry Division.

Despite some drawbacks, including the sedimentation of winter salts and sands that could reduce porosity without routine maintenance, Oneglia sees demand continuing to grow. “O&G is in the business of providing the best products possible to meet our customer’s needs and porous asphalt is one of the newest examples.”

The Perks of Porous:

  • Reduces the likelihood of flooding and heavy water accumulation
  • Eliminates storm-water runoff into sewer systems
  • Reduces the need for underground drainage infrastructure
  • Reduces the need for detention ponds and other stormwater management features
  • Reduces refreezing after snow and ice events Meets
  • LEED requirements for sustainability