Audubon, Nov-Dec 1993 v95 n6 p24(4) 
                Where the rubber is the road. (using recycled tire rubber in 
                combination with asphalt to pave public roads) Jim Gorman. 
            Brief Summary: The Intermodal Surface Transportation Efficiency Act 
            of 1991 has requirements that will allow the use of recycled rubber 
            tires in federally subsidized road construction, beginning in 1994. 
            With 20 pounds per ton of asphalt, roads will have increased 
            elasticity and temperature range. 
            Full Text: COPYRIGHT National Audubon Society 1993 
            Looking more like ground French roast than steel-belted radials, the 
            shredded, ripped, and sifted remains of old tires tumble down a 
            chute at Baker Rubber and into waiting canvas sacks at the rate of 
            three tons an hour. There's no mistaking the aroma inside this 
            factory on the outskirts of Chambersburg, Pennsylvania, though: 
            essence of tire store - definitely not coffeehouse. 
            For a closer look at the final product, plant manager Wally Eckman 
            clambers up to the mouth of the chute with the agility of a man far 
            smaller than his 270 pounds and grabs a sample of still-warm black 
            granules. "Now this right here is sixteen-mesh," he says. "It's a 
            hundred percent free of metal and ninety-nine-point-nine-five 
            percent free of fiber." Through a system of grinders, magnets, and 
            vibrating screens, his plant annually transforms rubber shreds and 
            shavings equal to nearly 2 million tires into a product sought after 
            by makers of mud flaps, cushioned flooring, railroad crossings - and 
            roads. 
            Crumbing, as the process is known in the trade, has been a 
            low-profile business for Baker and a handful of other rubber 
            grinders for decades. That is, until Congress passed the omnibus 
            transportation bill of 1991. Buried within the massive 320-page 
            Intermodal Surface Transportation Efficiency Act is the three-page 
            Section 1038, which requires states to lay rubberized asphalt in 
            some of their federally subsidized road projects beginning in 1994. 
            From an initial level of 5 percent of total tonnage, the law 
            advances the use of rubberized asphalt in 5 percent steps each year 
            to a quota of 20 percent of all federally assisted road building in 
            1997, where it will stay. States that come up short will find their 
            federal highway allotment for the next year pared back by the same 
            percentage as the quota. The rubber for all of that asphalt will 
            come from scrap tires, nearly 70 million of them by 1997. 
            When House and Senate conferees drafted Section 1038, they had two 
            over-riding objectives: Make a dent in the nations scrap-tire 
            problem, and build better roads. Asphalt peppered with scrap rubber, 
            they reasoned, could accomplish both. Now, with the mandate only 
            months away from taking effect, those three pages are causing an 
            outsize controversy that pits a small assortment of rubber shredders 
            and grinders, rubber-paving specialists, and environmentalists - who 
            like Section 1038 just fine the way it is - against conventional 
            paving contractors and state highway officials - who want it removed 
            or gutted. 
            The scope of the solid-waste problem posed by used tires in the 
            United States is something policymakers find hard to ignore. The 
            nation discards some 242 million tires every year - almost one for 
            every man, woman, and child. The Scrap Tire Management Council in 
            Washington, D.C., estimates that 2 to 3 billion tires blight the 
            American landscape, whether stashed in massive stockpiles, scattered 
            in fly-by-night dumps, or cluttering creeks and empty city lots. 
            The good news is that markets are opening up for this enormous mass 
            of highly engineered petrochemicals, steel belts, and nylon 
            filament. Last year about 68 million tires were salvaged, up from 24 
            million in 1990. A small but respectable number of these are used in 
            civil engineering projects or ground down in operations such as 
            Wally Eckman's; but the bulk - 58 million - head for combustion 
            chambers at power plants, cement kilns, and factories. 
            "No one can argue when it comes to scrap tires that we're doing 
            everything we can to adhere to the hierarchy of reduce, reuse, 
            recycle," says Susan Birmingham, a campaign director at the U.S. 
            Public Interest Research Group's headquarters in Washington, D.C. 
            Tires release a tremendous amount of energy as they burn (each tire 
            contains the equivalent of two and a half gallons of petroleum), and 
            they also release a broad spectrum of air pollutants, including 
            heavy metals, arsenic, dioxins, and furans, the same compounds 
            released when coal is burned. 
            Crumbing old tires and combining the particles with asphalt pavement 
            will not challenge burning as the major disposal method. But at the 
            standard rate of 20 pounds per ton, it can increase the road's 
            elasticity, temperature range, and resistance to oxidation, which 
            can add up to fewer cracks, ruts, and potholes - in certain 
            applications. That caveat is important. Even rubber-pavement 
            contractors shy away from branding their product the panacea for 
            America's crumbling roads. And though proponents of rubberized 
            asphalt contend that their product lasts longer than conventional 
            asphalt, dampens highway noise, and enhances traction, "used 
            correctly" and "in certain situations" (most often extreme heat or 
            cold) are expressions that frequently precede any claims to 
            rubberized asphalt's virtues. 
            Opponents see things differently. "Linear landfilling" is what 
            Francis Francois labels this use of rubberized asphalt. He's the 
            executive director of the American Association of State Highway and 
            Transportation Officials (AASHTO), which, along with the National 
            Asphalt Pavement Association (NAPA), is leading the charge against 
            the crumb-rubber mandate. Both groups have testified before Congress 
            that the reputed longevity, performance, recyclability, and limited 
            health hazards of rubberized asphalt are overrated or unproven, but 
            at heart they appear to be reacting to a breach of protocol: The 
            federal government is telling them how to build roads. "The problem 
            is that the law mandates use"' says Francois. "This should be an 
            engineering and economic determination, not a political one," 
            comments Richard D. Morgan, the vice-president of NAPA. 
            Public road building and maintenance in the United States is a $35 
            to $40 billion industry, to which change comes slowly. Indeed, the 
            basic composition of asphalt pavement on American roads is largely 
            the same as when President Dwight Elsenhower signed the 
            interstate-highway system into existence. Although there have been 
            many innovations over the years in the way highways are designed and 
            laid out, the old mix of asphalt-concrete binder, stone aggregate, 
            and the occasional mineral filler has largely remained unchanged. 
            That inherent cautiousness is exactly what asphalt-rubber advocates 
            and congressional staffers wanted to circumvent in requiring the use 
            of rubberized asphalt. 
            At this stage in its development, rubberized asphalt can hardly be 
            classified as cutting edge. The material has been around since the 
            1960s, when Charles McDonald, an engineer for the city of Phoenix, 
            went looking for a way to stop pavement from cracking under the 
            intense desert sun. He found that blending crumb rubber with hot 
            asphalt binder before mixing in aggregate seemed to do the trick. 
            Arizona today is the unquestioned rubber-asphalt champ among states, 
            with 700 miles, or 10 percent, of its state-managed highways covered 
            in the material. Arizona's cities and counties also use rubberized 
            asphalt extensively, and Phoenix alone adds 200 miles to the 
            state-highway total. 
            California is catching up quickly. Jack Van Kirk, senior materials 
            chief and research engineer in the state's Department of 
            Transportation (CALTRANS), says his office prescribes "some kind of 
            rubberized strategy" in 90 percent of rehabilitation projects 
            statewide, using rubberized asphalt either as a stress-absorbing 
            interlayer between layers of conventional asphalt or as a surface 
            layer. 
            Additional cost has been an issue for Van Kirk and officials in 
            other states that have used rubberized asphalt. AASHTO pins the cost 
            of rubberized asphalt at 50 to 100 percent above that of 
            conventional asphalt; the Federal Highway Administration puts it at 
            20 to 100 percent. California's recent experience with rubberized 
            asphalt, though, could render the issue moot. Van Kirk says CALTRANS 
            recently released specifications that allow contractors to lay 
            rubberized asphalt at half the thickness of conventional asphalt in 
            most situations. This takes advantage of the material's flexibility 
            without compromising performance or longevity. "Once we did that," 
            says Van Kirk, "the cost factor dropped out of the picture." 
            In mid-June rubberized asphalt cleared its last hurdle before 
            Section 1038 could take effect: The Department of Transportation and 
            the Environmental Protection Agency issued a joint report to 
            Congress saying that, based on available research on the material's 
            recyclability, performance, and worker-health effects, there was no 
            reason not to proceed. 
            Undaunted, AASHTO and NAPA have continued their efforts to stall, 
            defund, or dilute the mandate. They may be succeeding. In late June 
            the Federal Highway Administration released guidelines that allow 
            states to count recycled pavement - which contractors routinely 
            strip off of roads and reuse in vast quantities already - toward 
            their 5 percent rubberized-asphalt quota for 1994. 
            "That just gives them another year to shoot down the mandate," says 
            Gordon MacDougall, executive director of the Rubber Pavements 
            Association, which is based in Washington, D.C. "This is going to 
            get a lot nastier." 
            But back at Baker Rubber's Chambersburg plant, there are signs that 
            some state highway officials are beginning to hedge their bets. As 
            of mid-July, paving contractors in Pennsylvania, New York, Vermont, 
            and Virginia had given Wally Eckman four new contracts for 
            rubberized-asphalt paving. 
             
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