Long before the green movement became de rigueur, RMC Research & Education Foundation-funded programs supported environmental preservation by advancing
Long before the green movement became de rigueur, RMC Research & Education Foundation-funded programs supported environmental preservation by advancing concrete operations, expanding product applications, and increasing the knowledge base of industry professionals. Today, widespread national emphasis on sustainable construction adds impetus to Foundation endeavors. The group’s diverse project funding and varied partnerships facilitate implementation of sustainable practices by offering resources to all parties that aim to positively impact the environment.
PERVIOUS ON PURPOSE
Though pervious concrete has been available for some time, its popularity has exploded within the last decade, driven largely by demand for innovative stormwater management solutions. In response, the Foundation collaborated with the University of Central Florida’s Stormwater Management Academy in partnership with the Federal Highway Administration (FHWA) and Rinker Materials (now Cemex) to examine pervious concrete performance with respect to stormwater management. The study also targeted proper construction and maintenance, key elements to the effectiveness of pervious concrete installations.
Besides stormwater management, pervious concrete’s contribution to environmental stewardship includes capturing contaminants and mitigation of heat island effects. At Villanova University, Urban Stormwater Partnership researchers are conducting a project Û funded jointly by RMC Research & Education Foundation, U.S. Environmental Protection Agency (EPA), and Prince George’s County, Md. Û that entails side-by-side comparison of pervious concrete and porous asphalt. The study will examine durability, maintenance requirements, ability to filter key pollutants such as hydrocarbons, and heat-island effect mitigation. Research findings are expected by year’s end.
Further, RMC Research & Education Foundation sponsored the purchase of equipment to investigate the impact on urban heat-island effect mitigation of pervious concrete’s thermal properties, without regard to its Solar Reflectance Index (albedo). Performed in conjunction with a larger EPA pervious-concrete project in Edison, N.J., the study is scheduled to provide final data in late 2009.
Despite considerable evidence for effective use of pervious concrete in areas prone to freeze-thaw cycles, e.g., results of the Foundation’s long-term field-performance study conducted at Cleveland State University, additional data was sought by some within the construction community. Consequently, the Foundation recently approved funding for further examination of pervious concrete use in cold weather climates. Providing the ultimate test amid Minnesota’s severe winters, research performed by the University of Minnesota Civil Engineering Department is expected to yield a report in spring 2010.
Additionally, the Foundation’s Board of Trustees was prompted by pervious concrete’s potential value for parking lots and sidewalks to fund a study examining pervious mix designs for wearing course applications. With FHWA and American Concrete Pavement Association participation, plus funding by the Department of Transportation’s Pooled Resource Fund, research is under way at Iowa State University’s Concrete Pavement Technology (CP Tech) Center. The project, extending throughout 2010, is expected to produce findings critical to realizing the goal of increased highway safety through greater noise reduction, improved skid resistance, and reduced road spray.
Receiving one pervious concrete research project proposal after another, the Foundation’s Board decided to sponsor development of the Pervious Concrete Research Compilation (PCRC) to note existing data and track studies in progress worldwide. Accordingly, the PCRC is a living document updated periodically to record new and completed projects, thereby providing a better understanding of pervious concrete and its potential applications.
RATCHETING UP RECYCLED CONTENT
To achieve maximum effect, recycling should incorporate all materials having potential for a second life. Thus, using fly ash Û a by-product of coal combustion Û in concrete mixes constitutes a significant ÎgreenÌ measure that may also enhance the end product. A relevant study, originally funded by the U. S. Department of Energy and completed through Foundation support, was conducted at the National Ready Mixed Concrete Association’s (NRMCA) Research Laboratory in College Park, Md. It demonstrated that producers may use a greater amount of fly ash in ready mixed without compromising strength and performance, while also attaining early-age strengths required for a particular application. A Guide for the Construction Team developed as part of the research will assist project principals in efforts to integrate more fly ash in mixes for a variety of projects.
Using crushed concrete aggregate (CCA) in new mixes also offers a recycling opportunity. Every day, numerous ready mixed facilities receive unused or ÎreturnÌ concrete from job sites. After hardening and crushing, the material can be reused as aggregate in fresh batches. Recycling crushed returned concrete reduces costs for virgin aggregate, as it minimizes the amount of waste deposited in landfills and related disposal expenses, ultimately saving the industry about $300 million annually. A report prepared at NRMCA’s Research Laboratory provides guidance on methodology for proper CCA use.
CONCRETE TO ÎLEEDÌ THE WAY
The influence of U.S. Green Building Council’s (USGBC) Leadership in Energy and Environmental Design (LEED) program has expanded nationwide as environmental issues gain prominence. According to USGBC records, dozens of states, localities, federal agencies or departments, public school systems, and institutions of higher learning have implemented a LEED program Û and the list continues to grow. To ensure that builders, architects, and concrete industry players understand what concrete can offer by way of acquiring LEED points, the Foundation funded development of the Ready Mixed Concrete Industry LEED Reference Guide. The publication is updated periodically as USGBC modifies its LEED program, and the latest edition incorporating 2009 changes was released this fall.
Sustainability through fuel savings also favors concrete in pavement selection. As consumers fearing yet another spike in gasoline prices call for more fuel-efficient cars, few may recognize comparable benefits of concrete roadways. A study at the University of Texas at Arlington (UTA) is examining fuel consumption among vehicles on concrete and asphalt pavements. Though not to be finalized until spring 2010, the research has produced preliminary results (see page 30 sidebar) indicating that cars driving on concrete pavements in urban areas save a significant amount in fuel usage. Equally important, the study indicates that concrete roadways reduce carbon dioxide emissions Û extremely good news, particularly for regions struggling to curtail emissions to meet air quality standards.
Also furthering the concrete industry’s long-standing tradition of environmental stewardship, the Foundation is funding development of Sustainable Concrete Plant Guidelines (see page 30 sidebar) to assist producers in ÎgreeningÌ their operations. In the marketplace, then, ready mixed suppliers following the recommendations can spotlight their environmental initiatives.
The Foundation emphasizes that its many successes have been made possible by the support of donors and partnering organizations. Most project deliverables and resources are available at www.rmc-foundation.org, or on a CD titled Research Supporting Sustainable Development.
Jennifer LeFevre is Program Director of the RMC Research & Education Foundation in Silver Spring, Md. As a 501 (C) 3 nonprofit, the Foundation supports research and educational programs that will increase professionalism and quality in the concrete industry.
SUSTAINABLE CONCRETE PLANT GUIDELINES
Formulation of Sustainable Concrete Plant Guidelines, funded by the RMC Research & Education Foundation, will help concrete producers implement in their operations various means Û large and small Û to promote even greater environmental stewardship at each facility. The guidelines will consolidate a sizable body of knowledge regarding the minimizing of concrete plants’ environmental impact on communities they serve. Quantifying the effect of sustainable practices within the ready mixed industry, the reference will encourage and abet the application of such measures.
Strategies for sustainability explored in the guidelines will encompass multiple categories, e.g., waste and water management, air quality, and energy efficiency. In addition to guidelines with a narrative, project deliverables will include a literature search, survey of select concrete plants, and carbon calculator. A companion document will detail implementation and environmental issues associated with each guideline, plus procedures to document compliance with given criteria. Late-2009 will see unveiling of the final project, conducted by West Main Consultants and William C. Twitty, Jr., P.E., with support and guidance from National Ready Mixed Concrete Association staff.
DATA FROM THE UTA FUEL CONSUMPTION AND EMISSIONS STUDY
|PCC = Portland Cement Concrete||Fuel Consumed
(million metric tons/yr)
|AC = Asphaltic Concrete|
|PCC, Constant Speed, Dry||3,598||12.70|
|AC, Constant Speed, Dry||3,775||13.32|
|PCC, Constant Speed, Wet||4,783||16.88|
|AC, Constant Speed, Wet||4,942||17.44|
|Estimates are based on total vehicle miles of travel in the Dallas-Fort Worth region alone|
FOUNDATION, PCA, MIT LAUNCH CONCRETE SUSTAINABILITY HUB
The Massachusetts Institute of Technology in Cambridge announced in early October the creation of a Concrete Sustainability Hub (CSH), a research center established on campus in collaboration with the Portland Cement Association and Ready Mixed Concrete Research & Education Foundation. The goal of the hub is to accelerate emerging breakthroughs in concrete science and engineering, and transfer that science into practice. The CSH will provide $10 million of sponsored research funding during the next five years, while researchers from MIT’s School of Engineering, School of Architecture, and Sloan School of Management are expected to participate in the hub’s activities.
The timing of the CSH launch coincides with the U.S. Environmental Protection Agency’s announcement that it is moving to enact rules that would curtail greenhouse gas emissions from power plants and large industrial manufacturers. If enacted, these rules would likely impose regulations on all U.S. cement plants. RMC Foundation and PCA leaders hope that results from CSH research will help ease the way for the industry to meet any changes that would result if these regulations are put into place.
CSH research initially will be organized into three focus areas: concrete materials science, building technology, and econometrics of sustainable development. The first two projects Û Green Concrete Science and The Edge of Concrete: A Life-Cycle Investigation of Concrete and Concrete Structures Û are under way.
Franz-Josef Ulm, Macomber Professor in the MIT Department of Civil and Environmental Engineering, will serve as the CSH’s inaugural director and is the lead investigator on the Green Concrete Science project. The CSH will be codirected by John Ochsendorf, Class of 1942 Career Development Association Professor of Building Technology in the Department of Architecture and Department of Civil and Environmental Engineering.
The concrete industry has the honor of producing the world’s most favored building material, said RMC Foundation Executive Director Julie Garbini. But, this honor comes with a responsibility for the industry to minimize its ecological footprint.
PCA President and CEO Brian McCarthy added, The MIT research team is an exceptional group of dedicated interdisciplinary faculty, and the CSH will take a holistic approach to research that allows science to feed seamlessly into today’s concrete applications like paving and wall systems. Ultimately, the greatest opportunity for the building industry to reduce greenhouse gas emissions may lay in the development of more durable and energy-efficient roads, houses and buildings.
Putting engineers together with economists, urban planners, architects and industry experts and practitioners on issues related to our built infrastructure will create truly novel opportunities, noted Subra Suresh, dean of Engineering and Vannevar Bush Professor of Engineering at MIT.