Martin Marietta Materials, Inc. is a producer of aggregates for construction industry, including infrastructure, nonresidential, residential, railroad ballast, agricultural, and chemical grade stone used in environmental applications. The Company operates in four business segments: the Mideast Group, Southeast Group, and West Group, collectively the Aggregates business, and the Specialty Products segment. The Company's aggregates business includes asphalt products, ready mixed concrete, and road paving materials.During the year ended December 31, 2011, the Company acquired the assets of aggregates, asphalt, and ready mixed concrete business located in western San Antonio, Texas; it exchanged certain assets with Lafarge North America Inc. and acquired a ready mixed concrete business in the Denver, Colorado area.