Mat foundation

Mat foundation is also known as the raft foundation. It is a continuous thick concrete slab on the soil that extends the entire footprint of the building and increases the soil bearing capacity power. This foundation supports the entire building loads and safely transfer it to the ground

1. MAT FOUNDATION Presented By A.Bharat kumar

2. WHAT IS FOUNDATION? It is the lowest part of a structure below the ground level Has direct contact with ground. It provide a base for the super-structure through artificial arrangement of concrete block, piles, raft etc.

3. MAT FOUNDATION A mat foundation is a thick reinforced concrete slab supporting arrangement of column’s or walls in a row and transmitting the load into the soil. It is use to support storage tanks , industrial equipment’s , chimney’s and various structure.

4. MAT FOUNDATION

5. WHY IT IS USED The spread footing cover over 50%of the foundation area because of large column loads. The soil is soft with a low bearing capacity. When the expenses of deep foundation is higher than raft foundation. Walls of the structure are so close that individual footings would overlap.

6. TYPES OF MAT FOUDATION Flat plate mat Plate thickened under columns Two-way beam and slab Rigid frame mat Piled raft Plate with pedestal

7. Soil test Bearing capacity of soil Classification of soil Moisture content Ground water level Appropriation and depth of mat

8. Shore pile construction Shore piles support the surrounding loads and prevent the surrounding soil form breaking in at the time of construction Steel sheet shore Concrete pile shore

9. Steel sheet shore Concrete pile shore

10. Excavation Soil excavation to acquire the desired depth. two types of excavation’s are: Manual excavation Machine excavation

11. Manual excavation Machine excavation

12. Brick layer over compacted soil Cement concrete layer over BFS layer CC layer construction

13. Reinforcement A batch of horizontal reinforcement placing. Another batch of reinforcement placement to complete the bottom mesh Column rod placement Vertical rod place over bottom mesh to hold the upper mesh Upper mesh placement

14. Column positioning

15. Form work From work is a mould (or) open box , like container into which fresh concrete is poured and compacted. When the concrete is set , the form work is removed and a solid mass is produced in the shape of the inner face of the form work.

16. Types of form work Timber form work Plastic form work Steel form work TIMBER FORM WORK

17. Plastic form work Steel form work

18. Casting Start from one end. Layer basic casting. Side basic casting.

19. Compaction

20. Leveling After casting and compaction , leveling is a must to get the same thickness all over the mat slab. Two types of leveling. Manual leveling Machine leveling

21. Manual leveling Machine leveling

22. Curing Types of curing Shading concrete work. Steam curing. Ponding method. Sprinkling of water. Covering concrete surface with gunny bags.

23. Advantages The foundation and floor slab is combined , which saves time and material. Load are spread over the whole area of the structure. It can cope with mixed or poor ground condition. It requires little excavation. It reduces differential settlement.

24. Disadvantages It require specific treatment for point loads. Edge erosion occur if not treated properly.

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