RAP – Reclaimed Asphalt Pavement:

EJB Paving & Materials Company has always been environmentally concerned about conserving energy and our natural resources. Since 1984, Breneman has been using certain percentages of RAP in its hot mix asphalt production. Governed by the Pennsylvania Department of Transportation guidelines and specifications, only smaller percentages of RAP have been allowed to be introduced into new hot mix asphalt.

Since 2007, 24 states have increased the allowable percentage of RAP in their new asphalt production and pavements. Pennsylvania is one of those states. Using RAP can save states a good deal of money. To mill, haul and process RAP costs only a fraction of the cost of virgin mixtures. RAP or millings, as it is so often referred to, contain some of the United States´ best quality aggregates. In the past, when good quality rock was uncovered in quarries it was easier to extract the plentiful high-graded aggregates and use them for new road base and asphalt production. In today´s world, those good-quality aggregates are harder to find and are more expensive to excavate, crush and size. Here on our highways, roadways and parking lots, we have an abundance of good, high-quality material that has come to the end of its useful working life. These are the same high-quality aggregates that were mined and crushed many years ago, and they can be useful once again when we recycle these aged, brittle and cracked pavements into new hot mix asphalt overlays. Gone are the days of just hauling the spent and broken asphalt pavements to a dump site or backfilling an open pit or mine. Since the introduction of “Milling Machines” to the construction industry, it has become much easier to remove asphalt from the road surface. Milling of the old worn-out asphalt also partially sizes the material, so it is much more economic to re-crush the RAP back into new hot mix asphalt. RAP allows contractors to produce lower-cost hot mix asphalt and pass the savings to owner agencies. Using RAP is a “Green Technology”.

WMA - Warm Mix Asphalt:

Warm mix asphalt is the generic term for a variety of technologies that allow the producers of hot mix asphalt pavement materials to lower the temperature at which the material is mixed and placed on the highway. Reductions of 50-100°F have been documented. Such drastic reductions have the obvious benefit of cutting fuel consumption and decreasing the production of greenhouse gases. In addition, potential engineering benefits include better compaction on the roadway, the ability to haul hot mix paving materials long distances, and the ability to pave at lower temperatures.

In the next few years, the whole construction industry will be changing the way it conducts its business. The industry is being forced to reevaluate how it impacts the environment. Sustainability - the use of resources that allow us to meet the needs of the present while providing for the needs of future generations - is the primary goal of every respectable contractor and government agency. Gone are the days of "what was good for the last generation should be good for the future". There are over two million miles of paved roadways in the United States, and 94 percent are surfaced with asphalt. That is one very big resource and one very expensive investment. We need to keep making that investment; and we need to keep inventing new and environmentally-safe and operationally-safe ways to manufacture and construct hot mix asphalt, so that as you move around the nation what you see and what you drive on is providing you with the very best experience possible.

In 2002, leaders of the National Asphalt Pavement Association organized a study tour, visiting some European Countries and learning more about warm-mix technologies. Research began immediately at the National Center for Asphalt Technology to validate the benefits and explore the opportunities of warm-mix asphalt. EJB Paving & Materials Company is one of the companies that see the advantages of "green asphalt" and is going "black to green", in keeping with the times. Warm mix asphalt is an important step in sustainable pavements and conserving our natural resources. EJB is reducing its carbon footprint day by day.

The process and equipment used in warm-mix asphalt are, in many ways, the same as traditional hot-mix asphalt. The engineered mixture of aggregate, sand, gravel and asphalt cement (bitumen) is produced at an asphalt plant. Usually, the ratio is about 95 percent aggregate to 5 percent asphalt cement. Asphalt cement is the binder - the glue that holds the pavement together. At the plant, the aggregates are heated, driving off moisture. The hot aggregate is then mixed with asphalt cement, and the heat facilitates the mixing and coating process. About 500 million tons of asphalt pavement material is produced each year in the U.S. using these methods. Warm-mix technologies fall into two basic categories; one uses a small quantity of water to create foaming of the asphalt, and the other uses chemical additives. Both technologies result in a mix that can be placed on the roadway at reduced temperatures when compared to conventional practices. Hot mix asphalt is usually produced at about 280°F to 340°F. Warm mix asphalt technologies allow production temperatures to be reduced to approximately 215-275°F.

The asphalt industry is the United States´ number one recycler. Every year, over 100 million tons of old asphalt is recycled. Of that number, 75 million tons of reclaimed asphalt pavement (RAP) is mixed with virgin materials and incorporated into a new hot mix. The fuel savings are estimated at about 30 percent; depending on such factures as temperature reduction and moisture content of the aggregate and RAP. There are also added benefits of hot mix asphalt plant reduction in emissions. Once the warm mix arives at the construction project and the material is laid in-place, the compaction effort to reach the mix design density will be easier to obtain. Compaction is critical to long-term performance of the pavement. The warm mix technologies are compaction aids that improve the workability of the mix. Temperature is also a factor. Cooling of warm mixes is slower than cooling of hot mixes because the difference in temperature between the warm mix and the ambient is smaller. Therefore, warm mix can be used for paving in cooler weather.

Such drastic reductions have the obvious benefits of cutting fuel consumption and decreasing the production of greenhouse gases. Potential engineering benefits include better compaction on the road, the ability to haul paving mix for longer distances, and the ability to pave at lower temperatures. All these benefits are moving EJB Paving & Materials Company into the era of sustainable pavements.

As the United States goes green, asphalt is keeping pace with the times. Warm mix is an important step in sustainable development, simultaneously conserving natural resources, reducing the carbon footprint of the industry, and improving the equality of the pavements that Americans rely on so much.