Landscape Architect & Specifier News

APR 2014

LASN is a photographically oriented, professional journal featuring topics of concern and state-of-the-art projects designed or influenced by registered Landscape Architects.

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Test results released by Solidia Technologies on February 19 show that their new process for curing concrete with carbon dioxide instead of water can reduce the carbon footprint of cement and concrete by as much as 70 percent, while producing higher-performing concrete products. Solidia Cement, the key to the new concrete technology, is primarily composed of low-lime and contains calcium silicate phases, which react with gaseous carbon dioxide (CO 2 ) in the presence of moisture. During the carbonation curing process, calcite (CaCO 3 ) and silica gel (SiO 2 ) are formed to develop strength within the concrete. This is in contrast to the hydration process that occurs in Portland cement-based concrete, which involves a hydration reaction between high-lime calcium silicate phases and water to form calcium- silicate-hydrate gel and calcium hydroxide. The proprietary concrete contains the same raw materials as ordinary Portland cement, namely, fine and coarse aggregate, supplementary cementitious materials and chemical admixtures. Mixing and forming processes are the same as those used in standard concrete production. The new curing process sequesters up to 300 kg of CO 2 per ton of cement used. When the reduced CO 2 emissions associated with production are considered with the cement's capacity to sequester CO 2 during curing, the CO 2 footprint created by the cement's manufacture and use can be reduced by up to 70 percent compared to traditional Portland cement. 20 Landscape Architect and Specifier News h a rd s c a p e s n e w s Cookin' Up A New Asphalt The Brick Industry Association (BIA) has appointed new board officers and staff leadership following the retirement of outgoing President and CEO Gregg Borchelt, who has led the organization since 2010. "Our Board and Council members continually demonstrate a strong commitment to BIA and the American clay brick industry," said Ray Leonhard, BIA's new President and CEO. Leonhard previously served as the group's Chief Financial Officer and Vice President of administration. Hanson Brick Senior Vice President Charlie Ward, also general manager of Hanson Brick Products-Light Products, will serve a two-year term as BIA's Chairman of the Board. Ward succeeds former Chairman Brett Packer, President of Packer Brick. The new BIA Vice Chairman is Sam Strang, President of Alley-Cassetty Brick, succeeding Bob Belden, President and CEO of The Belden Brick Co. Joe Rice, President of Belden Tri-State Building Materials, was named secretary, replacing Ward. The BIA appointed new officials to its top positions last month, including a new chief operating officer, chairman of the board and other executive staff. Washington State University researcher Haifang Wen (pictured) has created a "bioasphalt" mixture from waste cooking oil that binds aggregate at a lower temperature and a lower cost than the common petroleum-based method, without sacrificing strength or reliability. CredIT: WSU NeWS Washington State University civil engineering assistant professor Haifang Wen has developed an asphalt binding agent from leftover restaurant cooking oil that could be cheaper, more sustainable and just as reliable as its petroleum-based counterpart. Asphalt binder, which holds crushed stone and sand together to form pavement, only accounts for about five percent of the final hot mix asphalt (HMA) that gets steamrolled into surfacing. Since HMA has to be tough enough to withstand the rigors of weather and heavy truck traffic, Wen subjected each component of his bioasphalt to a series of rigorous stress tests, including intense heat, freezing temperatures, compression and loading. "We are shooting for summer 2014 to construct a trial road—probably at least a quarter mile long," Wen said in a WSU statement. Made from the residue left behind after production of gasoline, plastics, and other materials, traditional asphalt commands $700-800 per ton, or half the price of gasoline at $1,500 per ton, Wen estimates. "In general, a one-mile road in a rural area costs at least a million dollars to build," Wen said. "With the waste cooking oil technology, we can reduce the cost of asphalt binder to under $200 per ton, making road building much cheaper." Solidia Technologies, a New Jersey-based company that produces sustainable construction products, has announced a new concrete mixture that consumes carbon dioxide during curing. Brick Association Lines Up New Leadership High-Performance Green Concrete Cures With CO 2 , Cuts Carbon Footprint 20-21.indd 20 3/25/14 3:30 PM

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