COVER STORY BY DON MARSH Carbon Control National Ready Mixed Concrete Co. links leadership in low carbon mixes to business growth. Increases market presence with green building expertise, digital EPD technology, port-land-limestone cement and a growing RNG-fueled fleet. Development of credible accounting methods for all carbon dioxide emissions attributable to fresh and finished concrete is a marathon whose course tracks the Raw Materials, Transport, Manufacturing phases or Product Stage, plus Construction Process, Use and End of Life Stages. Environmental product declarations (EPD)—the baseline tool for carbon-minded architecture, engineering and construction interests—offer credible verified accounting for the first three stages. Top of mind for AEC professionals reviewing a concrete EPD is the “global warming potential” metric expressed as CO 2 kilograms equiv-alent/cubic yard (kg CO 2 -eq/yd.) Major investments in fleet and fueling infrastructure, plus informa-tion technology and technical services teams, have California-based National Ready Mixed Concrete Co. (NRMCC) set to calculate and seize CO 2 reduction opportunities in the Product Stage, thoroughly quantified in the company’s deep EPD library, and the less profiled Construction Process, where mixer fleet fuel consumption is a key carbon data point. CO 2 factors in the latter have traditionally been overlooked or not fully appreciated. NRMCC is at the forefront of demonstrating the carbon reduction potential of migrating from diesel to compressed natural gas (CNG) as its main fleet fuel. The producer is compounding the lower carbon factor by quickly ramping up one of the largest cement, aggregate and ready mixed fleets to run compressed renewable natural gas (RNG), whose greenhouse gas (GHG) profile—measured on a California Air Resources Board (CARB) scale as grams of CO 2 equivalent/megajoule— runs as deep as negative 283.27 versus positive 100.45 for diesel. A first phase of fleet fuel transition has seen NRMCC order a combined count of 120 vehicles; mixers, dumps and tankers, along with awarding contracts for construction of four CNG/RNG fueling stations. The first station opened last year at the producer’s Vernon plant, a twin alley powerhouse on the edge of downtown Los Angeles sporting 1,100 tons of cementitious storage and 5,000 tons of live aggregate storage. PLANT, SITE PHOTOS: Gus Rios , National Ready Mixed Concrete Co. The most widely recognized environmental product declarations (EPD) are prepared according to International Organization for Standardization guidelines, and define four stages for which sup -pliers, producers or manufacturers can track emissions. EPDs for ready mixed concrete have focused on carbon dioxide emissions (CO2) across the Product Stage. NRMCC’s investment in renewable natural gas-fueled trucks significantly impacts both product stage and construction phase carbon reductions. 44 • November 2021 www.concreteproducts.com
Concrete Products November 2021: Page 44
