Texas welcome: C&D industry professionals network and learn at C&D World 2007.

Representatives from all aspects of the construction and demolition recycling industry gathered in San Antonio in mid-January for the annual meeting of the Construction Materials Recycling Association (CMRA) at the C&D World Exhibition & Conference.

Even the arrival of an ice storm, which brought unseasonably cold temperatures to Southern Texas, couldn't stop the more than 230 industry professionals who attended the event.

In addition to the exhibit hall, which featured products and services from 28 vendors, the event also offered numerous networking opportunities and educational sessions on a wide range of topics, including the outlook for the construction market in the coming year, issues facing recyclers of mixed C&D debris and dust control technology.

BY THE NUMBERS. The slowdown in single-family housing has gained a lot of attention, but activity in nearly every other construction segment is helping to keep builders, subcontractors and materials suppliers busy.

"The economy today appears to have many sources of strength (other than housing) that will support an expansion of construction in 2007 and beyond," Ken Simonson, chief economist with the Associated General Contractors of America (AGC), told attendees.

Simonson remarked that he is "quite optimistic about the outlook for non-residential construction," but added that the "outlook for residential looks a lot colder."

If his predictions for 2007 turn out to be accurate, it will be the continuation of a pattern that started in 2006, according to Simonson.

The AGC economist went on to described the home building market as being in "free fall," with new housing starts down 11 percent in November 2006 compared to November of 2005.

While this has caused a noticeable slump for home-building contractors, subcontractors and recyclers who serve the overall construction market can shift their attention to the commercial and highway construction segments.

The combined non-residential construction segments in November of 2006 showed a 16 percent gain in private spending and an 11 percent gain in public works spending, "almost perfectly offsetting" the residential slump, according to Simonson.

Simonson characterized current economic indicators as positive, including moderate GDP growth, low unemployment and an inflation rate that has "hit the sweet spot" at 1 percent to 2 percent as measured by the Consumer Price Index.

For demolition and construction contractors and their suppliers, several non-residential segments are in need of their services. The hotel, hospital, power plant and highway segments should all continue to boom in 2007, according to Simonson's forecast.

Even in the sluggish residential segment, not all the news is bad. "Already, a number of projects designed or started as condos have been repositioned for the rental market, and buildings designed for rentals are going up after a long hiatus," said Simonson.

IN THE MIX. Recyclers of mixed C&D debris have many opportunities, but the cultivation of markets for end products is needed for continued success, according to Terry Gillis of Recovery 1 Inc., Tacoma, Wash., who spoke about mixed C&D issues and answers.

Recovery 1 grew from a wood recycling business to handle a variety of materials from the mixed C&D stream, according to Gillis. However, wood fuel still represents the largest market the company serves.

But grinding wood debris for fuel isn't the only market C&D recyclers have access to, according to Gillis. High prices for scrap metal have changed the way many C&D recyclers handle their material, driving more businesses to attempt to salvage scrap from their material streams. "Metal has some of the highest value extract from commingled debris," said Gillis. Magnetic separation equipment provides a means to extract metal without incurring high labor costs and is employed at Recovery 1 and other mixed C&D operations, he said.

Construction and demolition debris streams each come with their own set of challenges, said Gillis. For instance, demolition debris faces heavy scrutiny because of potential harm from contaminants like asbestos. He recalled an instance where a contractor brought in what he thought were lengths of concrete pipe for processing. The material turned out to be piping made from nearly 90 percent asbestos. For this reason, Gillis said the processor cannot rely exclusively on the supplier of material and must have trained personnel on hand to conduct and review inspections of material.

Commingled construction debris is also difficult to process, he said. The sheer variety of materials, including appliances and packaging, makes sorting complicated. Site workers oftentimes bring in outside debris as well, which further complicates the process, said Gillis.

Gillis emphasized that having markets for end products is key for mixed C&D recyclers. Among the products Recovery 1 makes are mulch and alternative daily cover (ADC). The company also bales carpet, polyurethane foam, old corrugated containers (OCC) and plastic for sale. "If you're just building up a pile, you're a landfill," said Gillis. "You must have a product to market."

However, certain regulatory issues are complicating the market situation in the Northeast, according to Greg Wirsen of Green Seal Environmental Inc., Sandwich, Mass. Chief among these is the Massachusetts Waste Ban, which banned C&D material from disposal in the state as of July 1, 2006. While, in theory, this regulation is meant to encourage recycling, in practice, it can hamper diversionary outlets for C&D materials like using C&D fines for alternative daily cover (ADC) at landfills.

The ADC market in New England is also facing legislative challenges. In 2004, Wirsen said New Hampshire instituted a ban on using ADC at active landfills. Central Landfill in Rhode Island followed suit by banning all C&D fines aside from RecoverMat in 2006. Wirsen said concerns over the generation of H2S gas from the gypsum content in C&D fines is a primary driver behind such regulations. Wirsen discussed current studies being conducted at the University of New Hampshire to determine exactly what conditions lead to the formation of the problematic [H.sub.2]S gas. The university and fellow partners, including the CMRA, EPA, Massachusetts DEP and several representatives from the private sector, are putting together demonstration projects meant to prove that C&D material can be stored without generating [H.sub.2]S gas. Wirsen said the project's intent is to document how to successfully use C&D fines in a landfill environment and to set best management practices for landfill operating conditions.

Wirsen said he anticipated the state would approve the demonstration project. However, he added that Massachusetts was still in a crisis as far as C&D markets are concerned. The lack of diversionary outlets and landfill projects that use C&D are problematic, he said. He predicted that markets will allow C&D recycling companies to survive in 2007 and 2008, but he added that he expected profits and growth would be stagnant.

ROAD WARRIORS. Recycled aggregates can be used successfully in a number of highway applications, according to Charles Gaskin, director of construction for the Houston District of the Texas Department of Transportation (TxDOT), who shared his district's success stories with the material at a session.

Gaskin said the Houston District of TxDOT has had success using a variety of recycled aggregate materials, including recycled concrete aggregate, asphalt pavement, tires, asphalt shingles and industry/foundry sands. He said the district uses a large amount of recycled concrete because of the lack of native course aggregates, the costs of importing aggregates and a large steady supply of recyclable concrete.

The district first experimented with using recycled crushed concrete as cement treated base in the late 1980s. As a coarse material with very little binder, it easily segregates and wicks moisture. Because of these traits, crushed concrete works better in dry areas and is not recommended for use in wet conditions or under flexible pavement, Gaskin said. He added the material worked well under continuously reinforced concrete pavement.

The Houston District expanded the use of crushed concrete into Type A dry rip rap in the early 1990s, and first used the material for concrete paving and structures in 1996 on a rehabilitation project on a 5.8-mile stretch of Interstate Highway 10.

The concrete mix used on the rehab project included 6.5 sacks of cement, 1.5 inch recycled coarse concrete, 30 percent fly ash, 5 percent entrained air and recycled fine aggregate.

According to Gaskin, this project yielded positive and negative lessons. In light of higher creep values, recycled concrete aggregates are no longer allowed in structural concrete. In addition, the project showed recycled fine aggregate has an adverse effect on flexural strength and is not limited to 20 percent of the fine aggregate portion of the mix. The district also learned that the material is highly absorbent, making moisture control of recycled aggregate critical, Gaskin said. He recommended being selective in what is crushed, maintaining uniformity of material types in stockpiles and aggressively monitoring moisture for success in using recycled aggregate in concrete paving applications.

Gaskin added that recycled crushed concrete can also be used successfully as concrete traffic barriers, fines for asphalt pavement mix, shouldering up roadway edges and fill.

According to Gaskin, the Houston District has also had success using recycled asphalt pavement (RAP). He said the district used a large amount of RAP because of high costs of importing aggregates. He added that local contractors have developed a high level of experience using the material and that most of them have equipment that is capable of using recycled asphalt materials.

TxDOT specifications allow the use of 20 percent RAP in dense graded applications (non-surface hot mixes) and 30 percent in all other non-surface hot mixes. The Houston District allows 10 percent in surface mixes, 20 percent in dense graded (non-surface mix), 30 percent in all other non-surface mixes and 100 percent in cement-stabilized base.

Gaskin said RAP is firm, but porous, making it well-suited for use in shouldering next to pavement edges, lining ditches, providing temporary or permanent driveways and providing temporary side streets on construction projects. Using RAP in these types of projects produces several benefits, including reducing the amount of new aggregate required, reducing the amount of new oil required and reducing the overall cost of new asphalt mixes, Gaskin said.

Gaskin added that the Houston District has successfully used crumb rubber and tire chips in highway applications. He said crumb rubber was particularly suited to use in hot mix asphalt, especially in high-accident areas because it produces good friction.

When considering the use of recycled products, Gaskin advised potential users to consider the cost of collection and processing, the cost of manipulation to meet given specifications and location, as hauling becomes a major factor in pricing.

Additional information on Tx-DOT's recycling efforts is available at www.txdot.gov/recycling.

DON'T DUST OFF COMPLAINTS.

The creation of dust from concrete crushing and other processes undertaken by C&D recyclers should be addressed before it causes complaints, speaker Tad Wollenhaupt told conference attendees.

Wollenhaupt, president of dust-control equipment maker Air One Inc., Wareham, Mass., gave attendees an overview of different types of dust and how they are classified by regulatory agencies.

The fact that regulatory agencies such as the EPA and OSHA have classified dust by type and size illustrates that such agencies take dust seriously. According to Wollenhaupt, the reasons dust must be suppressed include its ability to cause respiratory problems from a health viewpoint and property damage from a liability viewpoint.

Suppliers offer several types of systems to suppress dust both at temporary job sites and at fixed facilities, according to Wollenhaupt. These systems use either water or a specialty chemical applied most often as a spray or mist.

Nuisance complaints about dust can be one of several ways that C&D recycling draws complaints and unwanted regulation, Construction Materials Recycling (CMRA) Executive Director William Turley told attendees.

In a overview for show attendees about why the CMRA is raising money for its "Issues and Education" advocacy fund, Turley noted that the presence of either dust or a large stockpile of material could convince a regulator that something dangerous is taking place.

Turley summarized several of the regulatory battles that the CMRA and some of its members have had to fight in just the past 12 months, including regulations involving the handling of gypsum scrap in New England, painted concrete in New Jersey and scrap wood in a variety of locations from New Hampshire to Washington state.

"We are trying to promote your viewpoint to [regulators and elected officials]," the CMRA executive director told show attendees. The ability to advocate is vital, he said, adding that the CMRA was very willing to do so. "We have a good story to tell."

C&D World, the annual conference of the CMRA, took place in San Antonio Jan. 14-16. The 2007 show was managed by GIE Media, Cleveland, publishers of Construction & Demolition Recycling and Recycling Today magazines.

The authors are editor-in-chief and associate editor of Recycling Today.