0137033451 pp7

Copyright ©2011, 2006 by Pearson Education, Inc.publishing as Pearson [imprint]

Construction Methods and Management, 8th ed.S. W. Nunnally

Chapter 7

PRODUCTION OF AGGREGATE,

CONCRETE, AND ASPHALT MIXES



PRODUCTION OF AGGREGATE

• To produce quality aggregate, rock or gravel must be excavated, loaded, and transported to an aggregate processing plant (crushing plant). FIGURE 7-1. Aggregate processing plant.

(Courtesy of Cedarapids, Inc.)




• Rock Crushers

• Feeders and Screens

• The Crushing Cycle

• Washers and Other Equipment




FIGURE 7-2. Portable cone crusher. (Courtesy of Kolberg-Pioneer, Inc., and Johnson Crushers International)




Table 7-1. Principal types of rock crushers and their characteristics




FIGURE 7-3. Major types of rock crushers.




Table 7-2. Gradation of jaw crusher output (percent passing—open circuit)




Table 7-3. Gradation of roll crusher output (percent passing—open circuit)




FIGURE 7-4. Apron feeder.

FIGURE 7-5. Three-deck vibrating screen.




FIGURE 7-6. Estimating screen capacity.




FIGURE 7-7. Aggregate flow through crushers.



PRODUCTION OF CONCRETE

• Concrete is produced by mixing portland cement, aggregate, and water. – In addition, a fourth component, an

additive, may be added to improve the workability or other properties of the concrete mix.




• Types of Concrete

• Concrete Components– Cement– Aggregates– Water

– Additives




• Mix Design

• Batching and Mixing

• Estimating Mixer Production

• Transporting and Handling Concrete




Table 7-4. Maximum water-cementitious material ratios and minimum design strengths for various exposure conditions (Courtesy of Portland Cement Association)




Table 7-5. Recommended slumps for various types of construction (Courtesy of Portland Cement Association)




FIGURE 7-8. Truck mixer. (Courtesy of Kenworth Truck Company)



PRODUCTION OF ASPHALT MIXES

• Asphalt and Other Bituminous Materials

• Handling Bituminous Materials

• Asphalt Plants

• Estimating Asphalt Plant Production




FIGURE 7-9. Asphalt batch plant.




FIGURE 7-10. Components of a drum-mix asphalt plant.




FIGURE 7-11. Insulated hot-mix asphalt storage bin with skip hoist. (Courtesy of Terex Road Building)

0137033451 pp7

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