Vacuum concrete

IT IS ONE OF THE TYPE OF CONCRETE

1. Vacuum concrete A project on

2. contents Introduction Need for vacuum concrete Equipments Applications Advantages Disadvantages

3. INTRODUCTION Vacuum concrete is the type of concrete in which the excess water is removed for improving concrete strength. It was first invented by billner in united states in 1935. Reducing the final water –cement ratio of concrete before setting to control strength and other properties of concrete.

4. NEED FOR VACUUM CONCRETE The chemical reaction of cement with water requires a water –cement ratio of less thsan0.38. But it is always taken more than 0.38. Workability is also important for concrete. Workability and high strength don't go together as their requirements are contradictory to each other. Vacuum concrete is the effective technique used to overcome this contradiction of opposite requirements of workability and high strength.

5. Equipments use in vacuum concrete Vacuum pump with hose pipe

6. Filtering pad

7. Screen board vibrator Water separator

8. Power trowel Power floater

9. Producer With the help of screen vibrator the surface is vibrated . Vacuum pump is small but strong pump of 5to 10HP. The mats are placed over fine filter pads . Water from concrete is vacuum and stored in separator . About 3% reduction in concrete layer depth takes place . By the use of power trowel and power floater the surface is given a hard and smooth finish.

10. Vacuum concrete process

11. Application of vacuum concrete Industrials floor sheds like cold storage. Hydro power plant . Bridges ports and harbor . Cooling tower.

12. Advantages of vacuum concrete Increase of final strength of concrete by about 25%. Sufficient decrease in permeability of concrete. High density concrete. Increase of about 20% bond strength of concrete. Appreciable reduction of time for final finishing . Early removal of wall forms . Increase in durability.

13. Disadvantages of vacuum concrete High initial cost . Need trained labor . Need specific equipments . Need power consumption . The porosity of concrete allows water /oil and grease to seep through ,consequently weakening the concrete.

14. Conclusion Good quality of floors and pavements can be obtained The compressive strength can be increased by 25-45%. Durability of the floor can be increased m. 15-25% oil water can be extracted out.

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