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Ready mix concrete project ppt

readymix concrete

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Ready mix concrete project ppt

  1. 1. SHRI SHANKARPRASAD AGNIHOTRI COLLEGE OF ENGINEERING, WARDHA PRESENTATION ON MIX DESIGN PROCEDURE OF READY MIX CONCRETE DEPT. OF CIVIL ENGG. PRESENTED BY :-  ASHWAJIT WAGDE  KAILASH HAGAWANE  SURENDRA KHAIRKAR  RAHUL BORKAR  AKASH KUMBHALWAR GUIDANCE BY:-  MISS. MINAL LONKAR MAM  MISS. HARSHALI KOPARKAR MAM
  2. 2. INTRODUCTION Ready-mix concrete (RMC) is a ready-to-use material, with predetermined mixture of Cement, sand, aggregates and water.  The Idea of Ready Mix Concrete (RMC) was first introduced by Architect Jurgen Heinrich Magens, he got his patent of RMC in Germany in 1903. In 1907, he discovered that the available time for transportation could be prolonged not only by cooling fresh concrete but also by vibrating it during transportation.
  3. 3. The first concrete mixed off site and delivered to a construction site was effectively done in Baltimore, United States in 1913, just before the First World War. The first concept of transit mixer was also born in 1926 in the United States. In 1939, the first RMC plant was installed in United Kingdom and in 1933. Between the years 1950 and 1980 considerable growth of RMC took place in the United States. In India RMC was first initially was used in 1950 during the construction sites of Dams like Bhakra Nangal, Koyna.
  4. 4. • The increasing availability of special transport vehicles, supplied by the new and fast growing automobile industry, played a positive role in the development of RMC industry.
  5. 5. OBJECTIVE  Better quality concrete is produced.  Elimination of storage space for basic materials at site.  Elimination of Procurement / Hiring of plant and machinery.  Wastage of basic materials is avoided.
  6. 6. MATERIALS REQUIRED FOR RMC 1. AGGREGATE : Aggregates are the important constituents in concrete. They give body to the concrete, reduce shrinkage and effect economy. The mere fact that the aggregates occupy 70-80 per cent of the volume of concrete.
  7. 7. Aggregates are divided into two categories from the consideration of size • Coarse aggregate • Fine aggregate The size of the aggregate bigger than 4.75 mm is considered as coarse aggregate and aggregate whose size is 4.75 mm and less is considered as fine aggregate.
  8. 8. 2. CEMENT : Cement is a binder material which sets and hardens independently, and can bind other materials together. Cement is made up of four main compounds,  dicalcium Silicate (2CaO SiO2), tricalcium silicate (3CaO SiO2),  tricalcium acuminate (3CaO Al2O3), tetra-calcium aluminoferrite (4CaO Al2O3 Fe2O3). these compounds are designated as C2S, C3S, C3A, and C4AF.
  9. 9. where C stands for calcium oxide (lime), S for silica and A for alumina, and F for iron oxide. Small amounts of uncombined lime and magnesia also are present, along with alkalis and minor amounts of other elements.
  10. 10. 3. ADMIXTURE: • Air-entraining admixtures (mainly used in concrete exposed to freezing) • Water-reducing admixtures, plasticizers (reduce the dosage of water while maintaining the workability) • Retarding admixtures (mainly used in hot weather to retard the reaction of hydration) • Accelerating admixtures (mainly used in cold weather to accelerate the reaction of hydration)
  11. 11. • Super plasticizer or high range water-reducer (significantly reduce the dosage of water while maintaining the workability) • Miscellaneous admixtures such as corrosion inhibiting, shrinkage reducing, coloring, pumping etc.
  12. 12. FLY ASH: Fly ash is a by-product from coal-fired electricity generating power plants. The fly ash is generally used in the concrete in the following ways. As partial replace for cement. As partial replacement for sand. As simultaneous replacement for both cement and sand.
  13. 13. FLY ASH
  14. 14. WATER : The pH value of water should be in between 6.0 and 8.0 according to IS 456-2000.
  15. 15. rice husk / hull ash (RHA)  Today, rice is grown and harvested on every continent except Antarctica.  The majority of all rice is produced in India, China, Japan, Indonesia, Thailand, Burma, and Bangladesh. Asian farmers’ accounts for 92-percent of the world's total rice production.  More than 550 million tons of rice is produced annually around the globe.  That rice husk are used in RMC to
  16. 16. EQUIPMENTS REQUIRED: Storage of materials - Silos, containers and bins Batching arrangement Measuring and recording equipment Mixing equipment Control systems Electrical, hydraulic and pneumatic drives Conveying systems (belt / screw conveyors)
  17. 17. MIXING PROCESS: Thorough mixing of the materials is essential for the production of uniform concrete. The mixing should ensure that the mass becomes homogeneous, uniform in colour and consistency. There are three methods adopted for mixing Ready Mix Concrete.  Following are the three types of mixing process of RMC  1. Transit Mixed (or "truck-mixed") Concrete  2. Shrink Mixed Concrete  3. Central Mixed Concrete
  18. 18. MIXING PROCESS
  19. 19. TRANSIT MIXED(OR "TRUCK-MIXED") CONCRETE:- While ready mixed concrete can be delivered to the point of placement the overwhelming majority of it is brought to the construction site in truck-mounted, rotating drum mixers. Truck mixers have a revolving drum with the axis inclined to the horizontal. Inside the shell of the mixer drum are a pair of blades or fins that wrap in a helical (spiral) configuration from the head to the opening of the drum. The concrete is loaded and mixed, it is normally hauled to the job site with the drum turning at a speed of less than 2 rpm.
  20. 20. NEEDS TO BE SPECIFIED BY CONSUMER FOR RMC  Characteristic strength or grade (N/mm2)  Target workability or slump in mm required at site  Exposure conditions for durability requirements Maximum water to cement ratio  Minimum cement content  Maximum aggregate size  Type of cement  Mineral admixture and its proportion (Kg/m3)
  21. 21. CHECKS BY CONSUMER BEFORE ORDERING THE RMC  Calibrations of all measuring devices and their accuracy.  Mode of operation of plant should preferably be fully automatic and not manual.  Quality of materials proposed to be used.  Adequacy of quantity of materials used.
  22. 22. INSPECTION OF CONSUMER
  23. 23. Conclusion:  The concrete quality produced in RMC plant is highly consistent with low deviation order.  It provides a high degree of overall strength of hardened concrete and the performance of the structure at a later date.  RMC operations are highly mechanized and fully controlled through electronic controls and hence reduce the
  24. 24. REFERANCE: • Concrete technology •www.rdcconcrete.com •www.scribd.com •www.wikipedia.org/
  25. 25. THANK YOU

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