The old Kermit the Frog song "It's Not Easy Being Green" does not apply to the concrete industry. Many contractors are involved in sustainable initiatives both in their concrete services and their business practices.
Green is a broad concept lacking a formal definition. Kevin Johnson, founder and owner of K Johnson Construction in Sauk Raids, Minn., defines being a green contractor as being conscious of using alternative methods in construction and in your business operations.
Karen Van Heukelem, business developer for Colorado Hardscapes, Inc. adds, "Green concrete contractors use common sense to build smarter, more efficiently and with minimal impact on the environment."
Chris Klemaske, who works in project development with T.B. Penick & Sons Inc., says the company looks at the big picture when it comes to being green. "It's being aware of everything, from what kind of coffee cup you use to how the sealer we apply to our concrete affects the environment and our employees," she says.
"If you aren't already practicing 'green' building it would be in your best interest to start," says Scott Johnson, project manager for Gresser Companies, Eagan, Minn. "Because ready or not, it is where the industry is going."
There are many ways concrete can be green. Recycled concrete can be broken down and reused in subbase material. Recycled materials, such as glass and porcelain, can be used in other concrete and decorative concrete elements such as floors, countertops, desks and more. K Johnson Construction is currently experimenting with using recycled glass in the subbase underneath pervious concrete.
Webcor Builders LLC., San Mateo, Calif., has a comprehensive wood reuse program in place on all of its concrete jobs. "With some forethought - a radial arm saw and a workbench - it is amazing how much wood can be reused on a job in the form of edge forms, rips, blockouts, handrails, or taken back to our yard for reuse on another job. We exhaust all reuse options before opting to recycle," says Ted Huang, sustainability engineer with Webcor.
Pervious concrete paving is perhaps one of the best known green concrete services. Pervious is designed to help with stormwater runoff. Contractors interested in installing pervious concrete can become certified installers through the National Ready Mixed Concrete Association's (NRMCA) Pervious Concrete Contractor Certification Program. Colorado Hardscapes, Inc. is currently working on a new pervious concrete that will offer a more decorative appearance, Van Heukelem says.
Another green concrete service is building with insulated concrete, either with ICFs (insulating concrete forms), insulated cast-in-place concrete, or even insulated tilt-up and precast structures. Insulated concrete helps in controlling the temperature of buildings, usually allowing for less heating and cooling needs.
Concrete paving can help reduce temperatures on the outside of the building as well, Scott Johnson says. The lighter surface of concrete reflects light better than asphalt surfaces reducing the heat island effect and keeping the surface of the pavement cooler. Van Heukelem also suggests decorative concrete contractors could use lighter pigments, and Klemaske suggests using integral colors with high SRI (solar reflectance index) values, to help with higher reflectivity.
Some contractors incorporate supplementary cemetitious materials (SCMs) into their mixes. These materials replace some of the portland cement required in concrete mixes and reuse industrial by-products like fly-ash and blast slag, Huang says.
John Lee, director of engineered sales for concrete material supplier Cemstone, says materials such as fly ash can help reduce the carbon footprint of a building while increasing the quality of the concrete. "If you want to get on board with the sustainability aspect, work with your material supplier and be willing to try new things," he adds.