MAT/RAFT foundation presentation- Details of Construction

This powerpoint presentation was based on construction steps of mat/raft foundation

1. PRESENTATION ON MAT FOUNDATION Ahsanullah University of Science and Technology Dept. of Civil Engineering CE-200 Details of Construction

2. What Is Foundation ?

3. Types of Foundation

4. MAT FOUNDATION It’s a one continuous large footing spread over the entire construction area. It’s a thick slab having many columns which transfers loads coming through the columns directly to the soil.

5. Types Of MAT foundation

6. Why Mat Foundation Is Required ? When foundation area cover 50-60% of the total plot area When the bearing capacity of the soil is too low When Basement is needed

7. We Visited Sites We Visited We Visited Sites We Visited Site 1 : Bosnia Sir’s Project , 7/1, Kallyanpur , Mirpur Rd, Dhaka 1216 Dhaka Site 2 : Assure Group Project, Gulshan 1 Rashid Tower, Rd 21, Dhaka 1212, Site 3 : Dolmen Prime project , H-8, Block-H, Main Road, South Aftabnagar , Dhaka 1219

8. Construction Steps of a Mat Footing

9. Step 01 Soil Test Soil is tested for measuring capacity Mat Foundation is applied if bearing capacity is too low.

10. Step 02 Leveling and Centering Centering provides accurate height Ease of depth measurement Creates suitable terrain for excavation equipment Creates a level surface to work on

11. Step 03 Shoring To protect from shear failure of soil Facilitates safe underground working conditions Concrete Pile Shore Timber Pile Shore

12. Step 04 Soil Excavation Removes unnecessary substratum Provides necessary depth for placing BFS,CC & reinforcements

13. Step 05 Providing Strutting and Bracing Prevents shoring from collapse due to overturning Provides lateral support to shoring

14. Step 06 Compaction and Leveling of Soil Prevents structure from leaning one side to another Provides level working surface

15. Step 07 Provide POLYTHENE , BFS , CC layer First one layer of brick flat soling is placed over the area It prevents structure from leaning one side to another After that Cement concrete layer of 3” thickness is provided. Makes structure less susceptible to ground water table BFS LAYER CC LAYER

16. Step 08 Placing CC Blocks Blocks are provided to maintain clear cover at the bottom Provides protective cover for rebar through concreting

17. Step 09 Placing of Reinforcement Main bar on bottom mesh is placed Chair is placed to hold the top mesh at desired height

18. Placing of Reinforcement

19. Shuttering Provides the formwork for concrete placement Facilitates providing desired shape to concrete

20. Step 10 Concreting Provides the majority of compression resisting material Works in tandem with rebar to provide desired structural strength

21. Step 11 Vibrating Removes void from concrete mix Ensures proper consolidation

22. Step 12 leveling Ensures level surface Provides smooth finishes

23. Step 13 Curing Provides suitable condition for hydration reaction Immersed in water continuously for 28 days to obtain ultimate strength

24. Advantages: Great for building Basement It reduces differential settlement. The foundation and floor slab is combined , which saves time. Distributes loads over a larger area. Advantages & Disadvantages Of Mat Foundation

25. Disadvantages: Mat foundations need heavy reinforcement in certain areas, which can add up to the price of the manufacture As the slab has greater thickness, heat may trap inside during hydration reaction. Water may seep inside. Shore protection is needed. Advantages & Disadvantages Of Mat Foundation

26. This presentation is based on the observations on Mat Foundation in various sites & meeting with concerned Engineers & Workers. Conclusion The principal objective of this Presentation is to learn about Mat Foundation practically with structural view. Besides Mat Foundation we were able to learn other major & minor parts of a construction.

27. That’s All , Thank You !

28. COPYRIGHT  This presentation is copyright protected by Tahey Bin Mainur , department of Civil Engineering, Ahsanullah University of Science & Technology (AUST), Dhaka, Bangladesh, 2017.  If you want to present or use these slides for any purposes kindly please contact me.. Thank you for watching & your precious time !