Redi-Mix, a business unit of US Concrete, has supplied its low-CO2 concrete to six Dallas Independent School District schools for a net savings of 108.7 million pounds of CO2 emissions.
Additionally, the company says that US Concrete’s Aridus Rapid Drying Concrete was used at the Billy Earl Dade Middle School construction project to address aggressive scheduling requirements, cutting the construction schedule by 30 percent and yielding a similar reduction in construction overhead costs.
US Concrete’s low-CO2 concrete technology and process, called EF Technology, reduces carbon emissions by cutting the Portland cement content — a major contributor to greenhouse gas emissions — and using cement replacement materials. These engineered mixes produce carbon emissions savings, as compared to traditional concrete.
Since 2009, US Concrete and its operating companies have saved more than 1 million tons of CO2 from entering the atmosphere, the company says.
To address the Dallas Independent School District’s sustainability goals, low-CO2 mixes were selected for six of the district’s schools, and the majority of the materials were locally sourced. US Concrete’s local business unit, Redi-Mix, delivered these sustainable mixes to the following schools: Billy Earl Dade Middle School, Clinton P. Russell Elementary School, Ebby Halliday Elementary School, Thelma Page Richardson Elementary School, W.H. Adamson High School and Wilmer-Hutchins Elementary School.
The original construction schedule for the Billy Earl Dade Middle School was 14 months, risking failure to meet the school’s Aug. 26 opening date. Working closely with the general contractor Satterfield & Pontikes Construction and joint venture architects Kell Munoz and KAI Texas, the construction team selected US Concrete’s Aridus Rapid Drying Concrete to shorten the construction schedule. The use of Aridus Rapid Drying Concrete cut the construction schedule by 30 percent (from 14 months to 10 months) and cut construction overhead costs.
Aridus Rapid Drying Concrete was developed and patented by US Concrete’s National Research Laboratory, USC Technologies, to address recent changes in environmental government regulations that limit or restrict volatile organic compounds (VOCs) in flooring adhesives. While these new formulations can reduce the environmental impact of new flooring installations, the new adhesives are less durable and more susceptible to moisture-related issues, US Concrete says.
As a result, contractors have been forced to combat the problems by adding sealers or lengthening the drying time of the concrete, in hopes of reducing the risk of liabilities associated with the failures of floor coverings. In addition, these remedies increase the construction time and costs associated with the projects.
Aridus Rapid Drying Concrete consumes the excess water and accelerates the drying time, eliminating extended drying times and the need for costly and time-consuming topical products such as epoxies, the company says. As a result, Aridus Rapid Drying Concrete not only prevents moisture-related flooring covering failures, but also allows contractors to reduce construction schedules and costs.
KAI Texas architect Randy Barnett says he’s seen projects negatively affected by the changes in adhesives and resulting emulsification. Barnett says Aridus Rapid Drying Concrete doesn’t have these problems. Within 21 days, the construction team achieved the acceptable standard of measures — below 80 percent humidity — to start receiving the floor. Barnett says standard concrete typically takes between four and eight months to reach this point.
US Concrete also supplied about 80,000 cubic yards of its low-CO2 concrete for the new San Francisco 49ers stadium. The company says it expects the mixes selected, used for the auger cast piles and overall stadium structure, will reduce the stadium’s overall carbon footprint by 23 million pounds of CO2.