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Expanded Shale & Clay - About Us
The Expanded Shale & Clay (ES&C) group at Texas Industries, Inc. (TXI) is one of the largest producers of rotary kiln expanded shale and clay lightweight aggregate in North America, and the largest supplier of ES&C aggregates west of the Mississippi River.
TXI is a Dallas-based company, and a leading supplier of building materials, including cement, concrete and aggregate. With operations in six states, it is the largest producer of cement in Texas and a major producer in California. TXI is a major supplier of stone, sand, gravel and expanded shale and clay products, and one of the largest producers of bagged cement and concrete products in the Southwest. TXI is a publicly-traded company on the NYSE under the symbol TXI.
Industry Leadership
As one of the largest producers of expanded shale and clay (ES&C) in the United States, TXI is a leading supporter of research, independent testing and field studies to improve the overall manufacturing and application of the product.
The company works closely with the Expanded Shale Clay and Slate Institute (escsi.org) and its member companies to provide educational materials and the latest information to professionals in various industries that use the product.
TXI is also active in funding and advancing research among independent consultants and government experts. One example of the company's recent research participation includes working with the Texas Department of Transportation (TxDOT) and the University of Texas Center for Transportation Research to conduct laboratory and field tests of ES&C aggregate gradations that improve internal curing methods of mainline concrete paving.
Quality Control
To produce a superior ES&C product, TXI begins with a raw material of shale or clay, which is quarried near the company's primary manufacturing facilities in Texas, Colorado and California. Shale and clay meeting certain specifications are excavated, crushed and screened into various sizes.
Using careful quality control standards, these particles are then fired in a rotary kiln at temperatures exceeding 2,000°F. At these extreme temperatures, gasses form tiny air cells within the aggregate. A hard vitreous membrane, consisting mainly of silica and alumina, surrounds each air cell. The glowing red-hot aggregate is then discharged into a cooling container, screened and stored in several stockpiles.
Prior to shipping by barge, rail or truck transport, the ES&C is processed to precise particle size gradations, as required by the project engineer or customer.
Distribution
TXI's primary markets are Texas and California, the nation's most populous states, and the two largest cement markets in the United States. Texas and California also lead the nation in receiving the largest shares of federal highway construction funding. We believe population growth trends in both states will continue to generate increasing construction activity in these markets for years to come.
Our strategy focuses on achieving leading positions in these growing markets while maintaining a low-cost profile. TXI is the largest supplier of cement in Texas. Our current project to modernize and expand our California plant will make us a more efficient producer of cement in that market.
TXI's aggregate, ready-mix and packaged concrete operations are leading suppliers to markets that are primarily in the Texas region. We are also the largest supplier of expanded shale and clay aggregate products west of the Mississippi River.
The long-term outlook for construction growth in Texas and California provides us with attractive expansion opportunities. Over the next decade, we expect to increase our annual capacity to make cement by 50% — from today's 5 million tons to 7.5 million tons — through the California project and through two projects in Texas. The same construction growth trends should provide expansion opportunities for our other building materials operations as well.
Laying Foundation, Sustaining Life: ES&C's Benefits in the Realm of Sustainable Living
Along with myriad uses in horticulture, masonry, geo-tech, asphalt and a host of others, ES&C contributes to an environmentally-friendly, safe and fundamentally "green" existence by:
- Conserving energy
- Lowering trucking and other transportation requirements
- Maximizing structural efficiency
- Increasing concrete service life
- Improving skid resistance on asphalt pavements
- Improving storm water runoff with on site treatment
- Lowering the heat island effect
- Amending soil to improve landscaping
- Promoting green roofs
Why Expanded Shale & Clay
For more than 100 years, expanded shale & clay (ES&C) lightweight aggregates have been used in applications that require strength without excessive weight, such as in high-rise buildings and bridge decks. The unique properties of ES&C provide time-tested sustainable performance, while offering economical and environmental engineering solutions in structural concrete, geotechnical, asphalt, concrete masonry, and a host of other applications. In addition, ES&C allows designers greater latitude and flexibility in creating solutions to meet the challenges of dead load, energy budgets, terrain, seismic conditions, construction schedules and stringent budgets in today's competitive marketplace.
Benefits of using ES&C:
- Reduces dead loads
- Reduces lateral forces
- Reduces overturning forces
- Provides a high angle of internal friction.
- Free draining
- Water and acid insoluble
- High insulation value
- Chemically inert, and environmental friendly
- High strength and durability
- Readily available
ES&C is a unique, ceramic lightweight aggregate prepared by expanding select minerals in a rotary kiln at temperatures over 1000 °C. The production and raw material selection processes are strictly controlled to ensure a uniform, high quality product that is structurally efficient, durable and inert, yet also lightweight and insulative. Lightweight aggregates allow designers greater flexibility in creating solutions to meet the challenges of dead load, terrain, seismic conditions, construction schedules and budgets in today's marketplace.
TXI lightweight aggregate conforms to ASTM C330 standards for structural rotary kiln-produced lightweight aggregates.
Fire Ratings
Lightweight concrete structures have a higher fire resistance than normal weight concrete due to their low heat conductivity, resulting in better insulation of the reinforcement, leading to decreased heating of the reinforcement and reduced thermal stresses. ES&C is a better insulator and loses strength less rapidly in fire than normal concrete.
Production Process
Expanded shale and clay is a ceramic lightweight aggregate prepared by expanding select minerals in a rotary kiln at temperatures over 1000°C.
Myths and Facts about ES&C
Get the truth about expanded shale and clay.
