Making the cement and concrete industry more sustainable
From environmentally responsible aggregate extraction to the use of alternative and renewable energy sources to reduce reliance on fossil fuels for the cement manufacturing process, from rehabilitated quarries to the development of a new cement that emits less greenhouse gases during its manufacturing process, the Canadian cement and concrete industry is committed to innovation and to developing products, technologies, and practices that contribute to more sustainable construction and a greener future.
Over the last twenty years, Canada’s cement manufacturers have made significant progress in reducing the ecological impact of cement and concrete production, and remain dedicated to driving continuous improvement in all stages of the supply chain to enhance the sustainable value of concrete structures and roadways. Manufacturers continue to develop sustainability plans designed to reduce CO2 emissions, make the most efficient and effective use of fuels and raw materials, develop state-of-the-art sustainable products, and manage and minimize local impacts of their operations. They are currently pursuing five core strategies as key levers to reduce CO2 emissions.
The industry’s sustainability strategy builds upon that of the World Business Council for Sustainable Development Cement Sustainability Initiative, to which virtually all Canadian cement manufacturers are signatories.
Cement and Concrete Environmental Product Declarations
Environmental Product Declarations measure a wide range of environmental impacts (for example, greenhouse gas emissions, toxic substances, habitat destruction, water impacts, ozone depletion, etc.) at every step of a product’s life cycle - from raw material extraction and processing, to manufacturing, to distribution and disposal or recycling at end of life. Much like a nutrition label, they provide a standard way to communicate the environmental impact of available products and as such are an important part of the life cycle assessment of construction projects.
EPDs are an important tool not only for providing data and transparency on materials but also to support complex integrated design processes that help maximize the role that materials like concrete can play in advanced energy efficient design.
The Cement Association of Canada has registered EPDs for general use and Portland-limestone cements (Portland-limestone cement is branded as Contempra in Canada) with the CSA Group. The cement EPDs, which were prepared by the Athena Sustainable Materials Insitute, can be viewed on CSA Group’s EPD registry listings.
The Canadian Ready-Mixed Concrete Association will be the first to apply the newly registered EPDs for cement when calculating the Life Cycle Analysis (LCAs) and industry-wide EPDs for participating ready-mixed concrete plants across Canada. The LCAs and EPDs will be published for industry use in the fall of 2016.
The Canadian precast/prestressed concrete sector has already produced and registered EPDs for their precast products.
five Core Strategies to Improve the Industry’s Environmental Performance
1. Improving manufacturing operating energy efficiency Energy management is critical to the sustainability of the cement industry. Cement manufacturing is an energy-intensive process and the Canadian cement industry is highly motivated to maximize the energy efficiency of its operations. Electricity and fuel costs amount to nearly 40% of total cement manufacturing costs. The consumption of large amounts of energy leads to CO2 and air pollutant emissions, which in turn require significant resources to manage. Over the past 20 years, the industry has increased energy efficiency by as much as 16%, and reduced GHG emissions by 10%. While operational energy efficiency has now reached a point where achieving further important improvements is difficult, the industry continues to innovate to improve energy efficiency, reduce greenhouse gas emissions, and conserve conventional energy supplies while reducing production costs. It is also investing in potentially transformative technologies which could overcome this “law of diminishing returns” to achieve major reductions in energy use and associated emissions (see Use of alternative and renewable energy sources below).
Example: St Marys Cement ISO 50001 Certification
With a capacity of approximately 1.8 million tonnes of cement per year, the St Marys Cement Bowmanville plant became the first in North America to receive ISO 50001 Certification on November 15, 2011. The designation recognizes the plant’s success in achieving continual improvement of energy performance. This improvement was achieved through retrofitting, modification of the production process, and significant improvement in the facility’s electricity-use monitoring systems.
The company estimates for energy conservation since the initiative began in 2005 stand at approximately 10.3 million kwh — enough energy to power close to 880 Canadian homes for a year. View article
In 2014, St Marys Cement Bowmanville Plant received the Gold Award Certification in Energy Excellence.
Renewable Energy Sources
2. Use of alternative and renewable energy sources The Canadian cement industry is working closely with governments and other stakeholders to decrease its reliance on carbon-intensive fossil fuels. The use of alternative fuels and raw materials is an important lever for the industry to reduce its reliance on fossil fuels such as coal and petroleum coke and thus reduce CO2 emissions from cement production. Many of these alternative fuels are consumer waste or byproducts from other industries and recovering their energy value in cement making is a safe and proven form of energy recovery. This type of energy recovery reduces the need for fossil fuels while safely destroying wastes that would otherwise be deposited in landfills. Examples include construction and demolition wood wastes, municipal bio-solids, non-recyclable plastics and textiles, and the remaining tire fragments left over from tire recycling operations.
Cement kilns are well suited for the use of alternative and renewable fuels as the kiln process involves long residence times and very high temperatures, which destroy all combustible materials and incorporates the non-combustible components into the cement product. This is a triple win for the environment.
Independent studies have concluded using household garbage, tires, and even plastic to manufacture cement would produce fewer greenhouse gases and reduce the amount of waste sent to landfills than the fossil fuels currently used.
The kiln energy substitution rate of solid alternative fuels in Canada has significantly lagged behind those in Europe, but the Canadian cement industry is currently engaging with provincial governments in collaborative processes which is hoped will lead to greater understanding and acceptance of alternative and renewable energy sources and ultimately result in improved environmental performance for the industry.
Building on its history of continuous environmental improvement, the industry is now making deep investments in potentially transformative innovations in areas like carbon capture and reuse.
Example: At the Forefront of Innovation — St Marys Cement and the capture and reuse of CO2
In partnership with Toronto-based Pond Biofuels, St Marys Cement has embarked on a bold and innovative pilot project that will see the capture of carbon dioxide and other emissions from the cement manufacturing process and their conversion into oxygen and biomass. Biomass is a feedstock for a wide range of high value products such as biodiesel and other biofuels.
3. Use of supplementary cementing materials to reduce the amount of clinker needed Partially replacing clinker, cement’s main component, with supplementary cementing materials containing mineral components (gypsum, pozzolana, limestone, fly ash and slag) also contributes to reducing CO2 emissions from cement production.
Supplementary cementing materials can also add important properties to produce different types of blended cements. The amount of clinker in cement can be reduced by grinding and blending supplementary cementing materials (SCMs) — by-products from other industries, such as slag from steel and copper production, foundry sands from metal casting operations, and fly ash, bottom ash, and synthetic gypsum from electrical utilities — to produce blended cements.
This practice not only reduces CO2 emissions, improves air quality, and reduces energy consumption, it also makes use of materials otherwise destined for landfills and increases production capacity without requiring the installation of new kilns.
Currently the use of blended cements and SCMs to produce concrete typically replaces 20% of the energy-intensive clinker that would otherwise be required to produce a metre of concrete. The Canadian average of clinker to cement ratio is currently slightly higher than the global average ratio and the industry is pursuing its efforts to reduce this ratio.
4. Contempra A contemporary cement engineered for today's needs, Contempra reflects the industry’s commitment to innovation and sustainability. The use of Contempra cement in manufacturing concrete decreases CO2 emissions by 10% while still producing concrete with the same level of strength and durability as concrete produced with regular Portland cement.
Contempra’s contribution to lowering the industry's carbon footprint is significant since it reduces energy requirements at the very start of the cement and concrete manufacturing process: while cement typically represents only 11% of a concrete mix, it accounts for more than 80% of all energy required to produce concrete.
Contempra will contribute to more sustainable construction and cleaner air in Canada. Once it is adopted for all suitable concrete applications, it is expected to reduce Canada's greenhouse gas emissions by up to 900,000 tonnes annually, assuming an 85% of Canada's cement production is converted to Contempra. This is equivalent to taking 172,000 cars off the road, or planting 23 million trees.
Contempra is referenced in the National Building Code through the CSA A.23.1 standard under the name Portland-limestone cement. While the new cement is not yet permitted for use in sulphate exposure environments, additional testing in this area is ongoing. The CSA A23.1 Committee is currently reviewing the research data and will decide at its May 2013 meeting whether or not to lift the sulphate exposure restriction on Portland-limestone Cement.
An Environmental Life Cycle Assessment of Portland-Limestone and Ordinary Portland Cements in Concrete
A cradle-to-gate Life Cycle Assessment study of both Portland-limestone cement and ordinary Portland cement released by Athena Sustainable Materials Institute in 2014 demonstrates that Portland-limestone cement has lower impacts in all indicators and is about 10% better in greenhouse gas emissions.
5. Responsible land-management practices Limestone quarries are long-lived assets, operating for up to 50 years. During their operational life cycle, impacts on the local environment include dust, noise, and other factors that must be properly managed. Limestone quarrying is a comparatively low-impact activity as far as extraction industries go, but Canadian cement manufacturers have long recognized they are responsible for the effective management and rehabilitation of the quarries they operate, and they are committed to constant improvement in minimizing the ecological footprint of this process. As members of the Cement Sustainability Initiative, they are committed to draw up rehabilitation plans for their quarries and stakeholder engagement plans. In Canada, nearly 90% of cement plants have these plans in place. The responsible rehabilitation of quarries is key to restoring ecosystems and enhancing biodiversity.
Example #1: Holcim Canada and Environmental Defence Spearhead Socially and Environmentally Responsible Aggregates
Holcim Canada, in collaboration with Environmental Defence, launched Socially and Environmentally Responsible Aggregates, a not-for-profit organization aiming to create, administer and promote the certification of responsibly sourced aggregate in Ontario. The proposed standards and certification system will establish a new benchmark for adopting best practices from not just an environmental perspective, but also from a community aspect. Now merged with the Aggregate Forum of Ontario (AFO), the organization continues to drive efforts for collaboration between industry, government and community. The new standards aim to harmonize the communities’ interests around pits and quarries and the environmental need for responsible extraction and rehabilitation, as well as meeting the growing demand for aggregate in Ontario.
Example #2: Lafarge’s Brookfield Quarry Site In Nova Scotia’s Shubenacadie River Valley
Efforts are well underway to make Lafarge’s rehabilitated Brookfield Quarry site a haven of biodiversity in the region. In partnership with Ducks Unlimited Canada, Lafarge has worked tirelessly to plant trees and reestablish streams, ponds, and wetlands at the former quarry. The results speak for themselves: the 38-acre protected site has seen the return of rare turtles, herons, and aquatic species and Lafarge has earned certification from North America’s Wildlife Habitat Council. Featuring 1.8 km of walking trails through picturesque wetlands, the site was opened to the public in July 2009 and has since become a popular hiking destination for tourists and local residents.
Example #3: Lafarge’s ready mix concrete Harbour plant in Vancouver
Lafarge’s ready-mixed concrete Harbour plant in Vancouver is an example of the company’s commitment to terms of environmental stewardship and biodiversity. The plant is home to a bald eagles' nest. This has garnered attention from the community and conservationists since the careful development of the plant in 2010 to assure their stability in a tree overlooking Burrard Inlet. Since then, the pair have produced a set of young and once again in 2012 returned to nest, proving the plant is an environmentally-friendly home.
Example #4: Holcim Canada’s Dufferin Aggregates’ Milton Quarry
Aggregate extraction is a temporary land use. Once aggregate is extracted from a pit or quarry, the site is rehabilitated into productive wildlife habitats, wetlands, golf courses, recreational parks, urban uses, conservation lands, forestry, or agricultural lands.
Dufferin Aggregates’ Milton Quarry used landform simulation techniques to create escarpment cliff and talus slope environments supporting a diversified and connected natural system. The quarry now features lakes, wetlands and islands, and supports aquatic, terrestrial, and cliff habitats. The Milton Quarry has received over 50 industry and community awards for property enhancement, progressive rehabilitation and community relations. 1000 acres of land was donated to Conservation Halton for community use.
Example #5: Holcim Canada’s Dufferin Concrete installs Enviroguard on its fleet of trucks
Dufferin Concrete, a division of Holcim Canada, equipped its entire fleet of over 400 ready mix trucks with the innovative Enviroguard chute washout system that allows nearly 4 million liters of wastewater from being released into the environment annually. Enviroguard addresses the industry-wide environmental issue of properly disposing of chute wash water in a safe, cost-effective and eco-friendly way. In 2010, the company was honoured with the Ontario Road Builders Association Green Leadership and Sustainability Award in partnership with the Ministry of Transportation (MTO) and the Ontario Good Roads Association (OGRA). View Press Release. View Media Coverage.
2012 Environmental Performance Report
A reflection of the Canadian cement industry’s ongoing commitment to transparency with its stakeholders and the public, the 2012 Environmental Performance Report shares the industry’s updated data on its environmental performance. Read more