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 the products and services of 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, the 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 that will support an expansion of construction (other than housing) 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 2007 shakes out that way, it will be the continuation of a pattern that started in 2006, according to Simonson.

For a more complete 2007 construction market forecast, see "Picking Up the Slack," beginning on page 94.

IN THE MIX

There are many opportunities for recyclers of mixed C&D debris, 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. 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 stream. "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 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 sometimes bring in outside debris as well, which complicates the process, said Gillis.

Gillis emphasized that having markets for end products is key for mixed C&D recyclers. Among the products Recovery I makes are mulch, alternative daily cover (ADC) and also baled 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 I, 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 those made by 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 to determine exactly what conditions lead to the formation of the problematic H2S gas in landfill applications. (For a more detailed discussion of this project, see "Accentuating the Positive," beginning on page 44.)

Wirsen said he anticipates the state will approve the demonstration project. However, he added that Massachusetts is 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 predicts markets will allow C&D recycling companies to survive in 2007 and 2008, but he expects profits and growth will 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. The district uses a large amount of recycled concrete because of the lack of native coarse 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 (drains by absorbing) 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 both positive and negative lessons. Due to 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 now 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.

According to Gaskin, the Houston District has also had success using recycled asphalt pavement (RAP). He said the district uses 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 most of them have equipment capable of using recycled asphalt materials.

TxDOT specs allow 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.

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 TxDOT'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 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 shows 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 jobsites 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 both complaints and unwanted regulation, 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 can be enough to 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 the state of Washington.

"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, said Turley, and the CMRA is very willing to do so. "We have a good story to tell," he concluded.

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.

BY C&DR STAFF