Issue link: http://digital.canadawide.com/i/124234
"We're promoting the idea of structures lasting at least a 100 years. For instance, trying to avoid having to rehabilitate highways. Instead, we're suggesting to build them better the first time," says Brian Hall, managing director, sustainability and business development at CPCI. The Infrastructure for LIFE program notes that "accelerated construction" is a means to achieve the reconstruction and new construction of major projects, while minimizing delay and community disruption. But this approach is not just about building things faster. Instead, the program says, "It includes a range of techniques, processes and technologies to achieve the desired result of reducing congestion due to construction while improving quality and life." The CPCI Major Account Program (CMAP) was also recently launched and consists of a multi-pronged approach that should result in a higher level of service from CPCI members to national and key accounts, both in Canada and in the U.S. Among other things, CMAP would help mediate the kinds of issues that can arise when a client with dozens of outlets across the country, or continent, is dealing with a service provider with relatively few locations, Hall says. Another CPCI program available to both members and non-members, and launched just a few years ago, continues to support quality across the country's precast sector. "The CPCI's concrete certification program for structural, architectural and specialty precast products and systems is your best way of confirming that a precast manufacturer has an ongoing quality assurance system," Hall says. The program has become recognized for the stringency and frequency of its audits, he says. "Audits examine all aspects of the plant operation, including engineering practices, production methods, controls and management commitment. The numerically graded audit report is uniform coast-to-coast from large to small plants, and grades are non-negotiable, with an 80 per cent passing requirement." He adds that initial plant certification takes a minimum of 90 days, but says it is this level of scrutiny that enables a higher level of assurance for building departments and owners. Quality itself is not so much the issue with some of the testing and research that is being done with EcoChem Portland-limestone cement (PLC). It is a recently introduced PLC from Lehigh Cement that can result in up to 10 per cent less carbon dioxide emissions in manufacture, compared to Type GU Portland cement. "Precasters are doing testing on EcoChem to make sure it works for precast applications," says Brad Pope, manager of fly ash and technical services at Lehigh Cement, a division of Lehigh Hanson Materials Ltd. Companies that make precast structural products have liability concerns. They want to be sure that Lehigh's EcoChem is the right fit and to understand the timeline for when it reaches optimal compressive strength. But, outside of the structural sector, others don't need to assess a new product in this way. "Precast manufacturers of non-structural products are using EcoChem for retaining walls and blocks. These manufacturers have been using it for the better part of last year," Pope says. Nonetheless, the precast sector is continuing to expand its reach in the structural domain using standard cement – as it will likely do with products like EcoChem, once it is better understood. "Developers are seeing the benefit of total precast structures. They seem to be going to an almost unlimited height – in excess of 20 stories," says Anthony Franciosa, sales manager at Coreslab Structures. Today's precast high-rises include a wide range of precast products: load-bearing walls, interior and exterior hollowcore floors, and solid wet-cast balconies. "Now, even stairwells, stairs, landings and the elevator shaft walls are precast. We have a saying that goes, 'Pour your foundation and we'll take it from there.' There's no need for a poured column. We use a shear wall system. We also use precast for underground parking. There are no poured-in-place columns, beams or floor slabs. Using a total precast system means we can work with way fewer trades on site," Franciosa says. With Coreslab precast parts, a stairwell and stairs are installed just about in tandem with a new floor. This provides easy access for all trades and can improve site safety. "This type of precast construction has increased in popularity quite a lot over the last five years. Part of the reason is the lack of skilled trades available for job sites. With precast, far fewer are needed on the site," Franciosa says. Smaller precast outfits are also expanding their product range and improving their plant processes in support of that. Edmonton-based Concrete Inc. does a range of standard products as well as some architectural ones, says Rui Veiga, the firm's owner. The company's most recent equipment addition was a new batch plant to make concrete. "It's automated, so it makes for better accuracy and more speed," Veiga says. Besides conventional precast methods, tiltup construction can also have smaller on-site requirements for workers. "There are several benefits to tilt-up. It's cheaper to build. It's also faster to build, because you're using precast. The cladding is there already. Tilt-up is the finished [wall] and the structural wall at the same time," says Casey Klaassen, president of Mardina Construction Ltd. The company built its first tilt-up school in 1999, Whitemans Creek Bridge, Brantford, Ontario. By using factory precast concrete elements on the bridge superstructure and substructure, the Ministry of Transportation of Ontario was able to replace the entire bridge within seven weeks instead of several months associated with conventional construction. In conjunction with the precast concrete elements, the use of FRP reinforcing, along with UHPC for the joints, shear pockets and haunches, has significantly increased the structure's performance and durability levels. Photos courtesy Armtec. Precast Concrete p12-17Precast.indd 15 april 2013 /15 13-04-05 1:54 PM