US-CONCRETE
U.S. Concrete's mission is to become the leading supplier of ready-mixed concrete and concrete products in the United States by providing its customers exceptional service and value, by manufacturing the highest quality products, and by delivering them in a safe and timely manner, while furnishing a superior work atmosphere for its team members and creating exceptional value for its shareholders. read more
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Raw
Materials |
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Sand,
gravel, and cement are transported to the concrete plant by truck. Certain materials,
such as inert aggregates, are typically stored outdoors in stockpiles. Moisture-sensitive
materials, such as cement and flyash, may be stored in high-capacity silos. As the
materials are needed, they are transported by conveyor to large storage bins at
the top of the batch plant.
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Batching
+ Mixing |
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At the
start of production, dry materials from the upper storage bins are discharged into
the redi mix truck. The proportion of materials in the mix is
custom-designed to meet the specifications for each project. Proportioning is controlled
by computer to ensure quality control. The customer typically works with the ready-mixed
concrete producer to determine characteristics such as aggregate size, slump, air
content, and strength based on the intended use. Typical composition by volume is
about 10-15% cement, 60-75% aggregates, and 15-20% water. Entrained air bubbles
may also account for 5-8%. Using less water generally results in a higher quality
concrete.
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Transport |
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After proportioning is complete, the mixture is discharged into a truck-mounted, rotating drum mixer. Rotating-drum truck mixers typically have a capacity of 9-11 cubic yards and discharge the concrete from the rear. Because slump loss can occur during transit, it is required that the concrete be discharged on the job site within 90 minutes or before 300 revolutions after the addition of water to the cement. Admixtures may be added to the concrete mix in situations of extreme temperature or long delivery times. Types of admixtures include air-entraining agents, water-reducing agents, and set-retarding agents. Vehicle maintenance is extremely important for ensuring safe and efficient transport of concrete products. Concrete plants typically include a full service garage to maintain our fleet of trucks. |