What is a Sustainable Material?
The concepts of sustainability and sustainable development arose from concerns that our economic imperatives – the provision of products and services, the growth of communities and businesses – is proceeding at a rate and manner that undermines the earth's capacity to supply resources, absorb wastes, and support the incredibly diverse life that it does – including people. For all the benefits economic growth provided to society it was undermining the ecosystem integrity, social fabric, and health of all.
Hence, sustainability describes some aspect of maintaining our resources from the environment to the quality of life, over time. It can also refer to the ability to tolerate—and overcome—degradation of natural environmental services, diminished productivity due to man’s relationship to the planet and each other. From this we can infer that resilience is a prerequisite to sustainability.
From its genesis in the field of international development – people in the diverse fields of environmental science and advocacy, land and economic development, health, safety and social justice, began to use the concept to encompass the interdependence between these issue areas and apply it to the wide range of development activities - industry, construction, planning, transportation, agriculture and resource management.
So, what does it mean for a material to be sustainable? There are few absolute answers to this, but there are basic questions to ask as a starting point to assess the sustainability of any material.
When making choices, we don’t often have all the information to answer these questions. Even when we can answer all of these, there are trade offs between materials that excel in different areas, and within a particular material category, corporate practices vary. New technologies and innovations change the answer over time.
The concrete industry encompasses a range of products and processes. The basic components are water, sand, gravel, and cement. Sand and gravel are mined, usually quite close to their point of use. Cement is made from limestone primarily, heated and combined with other elements, then crushed into a powder. Mixed together, these components are formed, in factories or on site, into a wide range of structures and structural components inlcuding pavers, skyscrapers, houses, stores, offices, roads, bridges, curbs, floors, foundations, precast and masonry components, pipes, catch basins, tanks, cisterns, the list goes on. Concrete contributes to sustainable development on two levels then, as a major industry and as the most widely used component of our built environment.
There are a number of tools and frameworks for evaluating sustainability in materials, in business practices, in urban planning, in construction. Concrete inherently contributes to sustainability in many respects, and in others these tools are helping the industry set goals to foster improvements in their practices and their product lines to further the global movement towards a sustainable society. To date most sustainability or green voluntary certification programs attempting to qualify sustainable materials have focused primarily on energy, material, and water conservation; indoor environmental quality; and site selection and development. Each of these is an important aspect of sustainable building design and construction. However, the assumption that the basic building will be functionally resilient is not inherent in these programs.
We have captured the contribution of concrete to sustainability in four broad social values: stewardship of nature’s resources, in use and in the supply chain; stewardship of financial resources; safety and stability; and aesthetics.