EPD: Portland-limestone cement, ASTM C595, Type IL (Argos USA Corp., Ash Grove Cement, Buzzi Unicem USA, Inc., CalPortland Company, CEMEX USA, Continental Cement, Drake Cement, Federal White Cement, GCC of America, LafargeHolcim, Lehigh Hanson, Martin Marietta Materials, Inc., Mitsubishi Cement Corporation, Monarch Cement Company, National Cement Group, Salt River Materials Group, St. Marys Cement, Suwannee American Cement, Titan America LLC)
The product under evaluation is portland‐limestone cement as defined by ASTM C219 and specified in ASTM C595, ASTM C1157, AASHTO M 240, or CSA A3001. A hydraulic cement consisting of two or more inorganic constituents (at least one of which is not portland cement or portland cement clinker) which separately or in combination contribute to the strength gaining properties of the cement, (made with or without other constituents, processing additions and functional additions, by intergrinding or other blending) (ASTM C219). As per ASTM C595, portland‐limestone cement (Type IL) shall be a hydraulic cement in which the limestone content is more than 5% but less than or equal to 15% by mass of the blended cement. All cement products are composed of specific combinations of calcium, silica, iron and alumina and small amounts of additives to achieve a desired profile of properties (e.g., strength, color). Clinker, the principle intermediate manufactured product within cement production, is typically produced from a combination of ingredients, including limestone (for calcium), coupled with smaller quantities of materials such as clay, iron ore, and sand (as sources of alumina, iron, and silica, respectively). So common are these building blocks that a wide variety of raw materials are suitable sources, and some sources, such clay and fly ash, may provide multiple chemical components. Cement plants are increasingly turning to industrial byproducts that otherwise would be discarded, once completing detailed analyses to determine the effects of using a byproduct on the manufacturing process, cement performance and facility emissions. The U.S. industry average portland‐limestone cement, as found by this study, is 82.7% clinker by weight. Table 1 describes the cement’s composition by specific material resources.
USA