TXI, formerly Texas Industries, was set up in 1946 and now is headquartered in Dallas, Texas. The company is focused on heavy construction materials in the southwestern United States market (e.g. Texas and California). There are mainly three products: cement (Portland, masonry and oil well cements), aggregates, and concrete related products. Until 2012, Texas Industries owned 82 manufacturing facilities in six states.
Its Midlothian plant on the south side of Midlothian, Texas () is about 27 miles (43 km) south of downtown Dallas. When the plant was built it was the largest cement plant in the country.
The Chaparral Steel plant is next to TXI's cement plant in Midlothian. Chaparral Steel was spun off from TXI and later purchased by Gerdau in 2007 for $4.2 billion. At that time, Chaparral Steel was the second-largest producer of structural steel beams in North America and a major producer of steel bar product.
In 1994, with an annual revenue of $614M, the company ranked 500th on the Fortune 500 list by annual revenue.
In January 2014, Martin Marietta Materials (MLM), a rival provider of construction materials, agreed to buy TXI for $2.06 billion in stock. The combined company will operate under the name Martin Marietta with 7,000 employees and headquarters in Raleigh, N.C., Martin Marietta’s current home.
As of July 2, 2014, TXI became a wholly owned subsidiary of Martin Marietta Materials, Inc.