If ultra-energy efficient and top quality building is of interest to you; or if environmental impact concerns you, read on. If not, please pass this on to someone who might be interested. R-Value Concrete Structures is a leading installer of Insulating Concrete Forms, arguably the greenest and most energy efficient building method today. ICF's are simple to incorporate into your next home, and they always make very happy customers. Since a major part of an ICF is concrete, it only seems fitting to address how concrete is green.
(The following article is adapted from a bulletin published by the Portland Cement Association www.concretehomes.com) Building Green with Gray Concrete The buildings in which we live and work have a tremendous impact on our global environment. Sustainability or "green building" seeks to balance resource efficiency, health, and social concerns throughout the life cycle of a structure. Concrete has a variety of benefits to offer in achieving this goal. What is concrete? Concrete and cement are often confused. Cement is a gray powder that, when mixed with water, binds sand and aggregates together to create concrete. Concrete is the world’s most prolific building material. This "liquid stone" can be shaped to make roads, bridges, dams, hospitals, and homes. It is extremely Although making cement requires a great deal of energy, cement is only a minor portion (10%–15%) of concrete. The other ingredients, aggregates and water, are locally sourced and require very low energy to obtain.
Progress from Research The high temperatures needed for cement manufacturing make it a very energy intensive process. Both the fuel for heating and the chemical reaction from processing the raw materials generate carbon dioxide (CO2). Worldwide global concerns about climate changes have led industry researchers to find ways to minimize CO2 production. The result is a 29% decrease in carbon dioxide output during the past three decades. Research has also led to the use of industrial by-products in the manufacturing process. Let’s look at several examples. Pound for pound, used tires contain about 25% more energy than coal, and the U. S. generates millions of them. In 2001, about 25 million tires were consumed as fuel in cement kilns, reducing R-Value Concrete Structures uses 30% flyash replacement in it's ICF concrete, significantly reducing the embodied energy of producing our ICF buildings. The percentage of Portland Cement goes from approximately 11% to less than 8%! This also diverts a greater amount of waste from entering the landfills. A Cradle-to-Grave Perspective Concrete is an extremely durable material. Life spans for concrete building products are frequently double or triple those of other common building materials. Concrete is virtually unaffected by heat and cold, UV rays, and moisture. This reduces the waste created by the removal and replacement of weathered or moisture damaged materials.
Raw Material Production The predominant raw material for cement is limestone, the most abundant mineral on earth and readily available throughout North America (especially Michigan). An environmental study conducted in Canada(1) analyzed the site impact of logging, ore mining, and aggregate extraction. It concluded that aggregate quarries take a lesser environmental toll than the other construction materials. Quarries, the primary source of raw materials, can be readily reclaimed for recreational, residential, or commercial use, or they can be restored to their natural state.
Construction Phase Ever seen the piles of scrap lumber and sheathing filling dumpsters at a construction site? Concrete is ordered and mixed for each individual job. On-site scrap and waste are minimized and any leftovers can be recycled. ICF forms also generate very little waste, and any waste is fully recyclable. Rebar scrap is also recycled so that an ICF building from R-Value does not add to the waste stream!
Operational Phase Recently developed methods for building with concrete actually generate less CO2 than many traditional building methods. Research revealed that houses built with insulated concrete walls actually contribute less CO2 to our environment over the life span of a home than typical wood frame construction(2). Although the initial manufacture of cement is energy intensive, these high performance wall systems need less energy for daily heating and cooling. In about 5 years, the total CO2 produced by a typical wood frame home begins to exceed that of an insulated concrete home. This environmental benefit continues for as long as the home is utilized. These benefits are greater in cold climates like Michigan, and especially when one considers the reduction in cement usage of an R-Value ICF wall.
Concrete contributes to indoor air quality as new concrete does not have the off-gassing that is prevalent in many other new construction materials.
Demolition Phase Although concrete has one of the longest useful life-spans for construction materials, its usefulness does not end after its original purpose. In most urban areas, almost all concrete is crushed and recycled for use in road base and backfill. In some cases, it is recycled for aggregate in new concrete. Research continues to find new applications for recycled concrete.
Versatility The applications for concrete and cement-based materials is growing rapidly. Stucco, fiber–cement siding, and concrete roof tiles need minimal maintenance and provide long lasting protection from the elements. These products are also useful in fire prone areas where stray sparks can lead to devastating results.
For More Information All of the sustainability advantages of concrete construction are too numerous to address in this publication. Learn more about using concrete for environmental benefits at www.concretethinker.org. For specific information on how an ICF structure built by R-Value Concrete Structures LLC is the right choice for the environment, for your pocketbook, and for your health, click here, and also be sure to explore our site.
1. "Assessing the Relative Ecological Carrying Impacts of Resource Extraction," by Wayne B. Trusty and Associates Ltd. in association with Environmental Policy Research, submitted to Forintek Canada Corp. for its Sustainable Materials Project, August 1994 2. "Partial Environmental Life Cycle Inventory of an Insulating Concrete Form House Compared to Wood Frame House" by Construction Technology Laboratories, for Portland Cement Association, 2003, Serial No. 2464 "I do not prize the word cheap. It is not a badge of honor...it is a symbol of despair. Cheap prices make for cheap goods; cheap goods make for cheap men, and cheap men make for a cheap country!" President William McKinley (1843-1901) |
