components of building ppt
- 1. COMPONENTS OF BUILDING By, Ms. Priya Sarita Mane
- 2. The structure of a building essentially consists of two parts namely the sub-structure and the super-structure. 1. Sub-structure 2. Super-structure 1. Sub-structure:- It is that part of the structure which is below the ground level i.e. foundation. It also includes the portion below the ground level since the height between the ground floor level and the ground level is negligibly small as compared to the height of the building.
- 3. 2. Super-structure:- It is that part of the structure which is above the ground level or ground floor level. The principal parts of the super-structure which carry the structural or superimposed loads are, (i) Masonry walls, (ii) Pillars or columns, (iii) Beams, (iv) Lintels, (v) Arches, (vi) Floor slabs and (vii) Roofs etc. The other parts of the super-structure which do not carry any structural loads are, (i) Curtain or partition walls, (ii) Doors, (iii) Windows and (iv) Parapet wall etc.
- 4. A TYPICAL CROSS SECTION THROUGH DOOR AND WINDOW SHOWING ALL BUILDING COMPONENTS
- 5. Basic building components Super Structure Plinth D.P.C Walls and columns Floors Beams Roofs and slabs Lintels and Archers Doors and Window Chajjas Parapet Steps and Stairs Cupboard and Shelves Substructure Foundation
- 6. COMPONENTSOFSUB-STRUCTUREAND THEIR FUNCTIONS The various components or elements of sub-structure are as given below: 1. Foundation- It is the lowermost part of the building below the ground level and it forms the base of the building. It mainly consists of the base-course in cement concrete to fill all the pockets in foundation Functions or Purpose: (a) To transfer the load of the building uniformly to a larger area of sub-soil to reduce the intensity of load.
- 7. (b) To sustain the load of the building without yielding. (c)To provide a level surface for concreting and masonry work. Materials :- Plain concrete, Reinforced Cement Concrete (R.C.C.), Stones are used.
- 8. TYPES OF FOUNDATIONS Foundations can broadly be classified in two types, such as Shallow and Deep foundations. (I) Shallow Foundation When the depth of foundation 'D' is less or equal to the width 'B' it is called as Shallow Foundation or open foundation . Generally it is 3 to 4 m. The various types of shallow foundations are as follows. (i) Wall Footing (Strip), (ii) Column Footing, (iii) Inverted Arch Footing, (iv) Raft or Mat Footing (v) Grillage Foundation.
- 9. (II)Deep Foundation - When a stratum of good bearing capacity is not available at reasonable depth i.e. D > B and where other types of foundations such as grillage or raft foundations are not suitable, then deep foundation must be adopted to attain a bearing stratum which will be suitable in all respect. They are generally provided when depth of foundation is more than 5 meters. Types of Deep Foundations: Important types of deep foundations are- (i) Pile Foundation,(ii) Pier Foundation,(iii) Caisson
- 10. 2. Plinth- It is the portion of the sub-structure between the level of the surrounding ground and the level of ground floor. The filling between the ground floor level i.e. plinth level and ground level is known as plinth filling. Minimum height of plinth should be 45 cm above the ground level.
- 11. Functions:- To support the super structure and provide stability and strength. To transfer the load from the building to the foundation layer. To provide adequate grip or hold to the structure on the subsoil. To retain the plinth filling. To provide safety against rats, rodents, flood on roads, etc. To give aesthetic aspect to the elevation of the building. Materials: Stones, bricks are used.
- 12. 3. Damp Proof Course ( D.P.C.)- It is the layer provided in between the sub- structure and super-structure Functions: It prevents the entry of moisture into the foundation below and super-structure above and vice-versa. Materials: Stone slabs of impervious variety, plain cement concrete are used for damp proof courses.
- 13. COMPONENTSOFSUPER-STRUCTUREAND THEIR FUNCTIONS Different components or elements of the super- structure are as given below. 1. Walls- There are two types of walls. (1) Load bearing walls and (2) Non-load bearing Walls Functions: To enclose or divide the space to make it functional and useful. To transfer the load of floors to foundation. To provide privacy, security and protection against weathering conditions.
- 14. 2. Pillars and Columns- These are the structural vertical members of a building. Functions :- These are constructed at suitable intervals to provide lateral stability to the wall. Pillars and columns are constructed to provide support to the beams, slabs and transfer the loads to the foundation. Materials: These are constructed in bricks, stones, steel and reinforced cement concrete. These are constructed in various sizes and shapes such as square, rectangular, circular, etc.
- 15. 3. Doors- These are the movable panels constructed in the openings through a wall. Functions : They provide horizontal circulation. or movement of the inmates from one room to another of the building. Materials: They are made up of wood. ply-wood, plastic. metal and glass.
- 16. 4. Windows - These are the openings built in the walls. Functions: They provide light, air, cross ventilation etc. They also provide privacy and security. They should be built considering the direction of wind, exterior view i.e. aspect, prospect etc. Materials: They are made up of wood, ply-wood. plastic, steel and glass.
- 17. 5. Window-sills - These are provided below the windows Functions: They provide a uniform surface and support to the window and also protect the top of the wall from wear and tear. Materials: Materials used are stone-slabs and cement. concrete.
- 18. 6. Lintels and Arches – These are provided over the openings of doors and windows. Functions: Lintels support the load of the wall above the opening since the frame of the door or window is not strong to bear it. Materials: Lintels are constructed with sound timber and R C. C.
- 19. 7. Ceiling- It is the lower part of upper floors. Functions: They are used as insulators against sound and vibrations of upper floors. They are provided to look more pleasing and beautiful. Type: False ceiling made of plaster of paris, plastics etc'
- 20. 8. Beams- Beams are structural horizontal members of a building. Functions : These are constructed to support the floors and transfer their loads to the columns. They give lateral rigidity to framed structures. Materials: Materials used are timber, steel and R.C.C. Types: Beams may be simply supported, fixed or cantilever type
- 21. 9. Slabs - These are the horizontal surfaces supported on beams and columns. Functions: It provides space for the occupants to live, move and keep their materials. It distributes the load of the floors, uniformly and transfer it to the columns and walls through beams. It acts as floor or roof for multi storied buildings. Materials: The material used is R.C.C.
- 22. 10. Roof: This is the top most part of the building. Functions: It protects against sun, wind, rain, snow, thefts etc. Materials: It is covered with a suitable material such as country tiles, Mangalore tiles, Allahabad tiles, Asbestos sheets, Galvanized iron sheets or reinforced cement concrete.
- 23. Types of roof Flat Sloped Domes Lean-to-roof King post trussQueen post truss Cylindrical Spherical
- 24. 11. Finish For Walls- It is done by plastering, pointing with cement mortar or even painting. Functions: They protect the exposed surface, conceal the bad workman ship and give a pleasant look.
- 25. 12.FLOOR - A floor provides a plane surface to support the occupants, furniture and any equipment. Types of floor (1) Ground floors (2) Upper floors The different types of floor which are commonly used for floor construction is (1)Mud and Muroom (2)Stone (3)Terrazzo (4)Tiles (5)Timber (6)Rubber (7)Mosaic tiles (8) Brick (9)C.C (10)Marble (11)Asphalt (12)Glass (13)Granite (14)Plastic or PVC
- 26. TYPES OFSOILAND ROCKSAS FOUNDATION STRATA 1.Types of Soils- (a) Non-cohesive soils (b) Cohesive Soils 2. Types of Rock- There are three types of rocks such as- (i) Igneous rocks, (ii) Sedimentary rocks and (iii) Metamorphic rocks.
- 27. Igneous rocks: Rocks that are formed by cooling of Magana (molten or pasty rocky material) are known as igneous rocks. Ex. Granite, Basalt and Dolerite etc. Sedimentary rocks: these rocks are formed by the deposition of production of weathering on the pre- existing rocks. Ex. gravel, sandstone, limestone, gypsum, lignite etc. Metamorphic rocks: These rocks are formed by the change in character of the pre-existing rocks. Igneous as well as sedimentary rocks are changed in character when they are subject to great heat and pressure. Known as metamorphism. Ex. Quartzite, Schist, Slate, Marble and Gneisses.
- 28. CONCEPTOFBEARING CAPACITY The terms bearing power, bearing value and bearing capacity are used to denote the ability of the soil to sustain the total load of the structure without yielding or showing any settlement. Bearing capacity of the soil depends upon the physical properties of soil such as shape, size, density, surface texture, voids, frictional resistance, cohesion and moisture retaining capacity.
- 29. Ultimate bearing capacity The Ultimate bearing capacity is the theoretical maximum pressure which can be supported without failure. allowable bearing capacity or safe bearing capacity is the ultimate bearing capacity divided by a factor of safety. safe bearing capacity
- 30. PLATE LOAD TEST Plate load test is done at site to determine the ultimate bearing capacity of soil and settlement of foundation under the loads for clayey and sandy soils. So, plate load test is helpful for the selection and design the foundation. To calculate safe bearing capacity suitable factor of safety is applied. Apparatus for Plate Load Test on Soil Mild Steel plate Hydraulic jack Reaction beam or reaction truss Dial gauges Excavating tools
- 31. Procedure of Plate Load Test on Soil A Pit is excavated in the ground at which foundation is to be laid. The size of pit is generally 5 times the size of the plate. The depth excavated should be equal to proposed foundation depth. The plate used is made of mild steel. It may be square (0.3m x 0.3m) or circular (0.3m diameter) with 25mm thickness. After excavation of pit, at center of excavated pit steel plate sized hole with “Dp” thickness is excavated and arrange the plate in it. The Thickness of plate Dp is calculated by formula
- 32. After arranging the plate in central hole hydraulic jack is arranged on top of plate to apply load. Reaction beam or reaction trusses is provided for the hydraulic jack to take up the reaction. Otherwise a loaded platform is created (using sand bags etc.) on the top of hydraulic jack and provided the reaction. After that seating load of 7kN/m2 is applied to set the plate and released after some time. Now load is applied with an increment of 20% of safe load. Dial gauges are arranged at bottom to record the settlement values. At 1min, 5min, 10min, 20min, 40min, and 60min and after that for every one-hour interval the settlement is observed and noted. The observations are made until the total settlement of 25mm has occurred.
- 33. Plate Load Test
- 34. Truss loading In case of reaction truss loading, a truss is arranged on jack and both sides of truss are anchored to the ground with strong support. Two ends of truss are loaded uniformly, then truss transforms the load into the plate and settlement occurs. Load is applied with an increment of 2kN at every interval. Settlement is observed at different intervals as said in above method. For clayey soils, the observations are made until the rate of settlement is to be 0.2mm per hour.
- 36. Types of Foundation Shallow Deep Pile Pier Well or Caisson Spread footing Strap footing Combined footing Mat footing For walls for columns Rectangular Trapezoidal Simple Stepped Grillage Single Stepped Sloped
- 38. Spread footing - which spread the super imposed load of wall or column over larger area. Masonry walls have stepped footing with a concrete base. Suitable: when good bearing capacity available at shallow depth
- 39. Strap footing - If the independent footing of two columns are connected by a beam it is called a strap footing. Suitable: when extreme column very close to boundary of plot.
- 40. Combined footing - A spread footing which support two or more columns is turned as. Suitable- columns are close to each other
- 41. RAFT or MAT foundation – It is a combined footing that covers the entire are beneath a structure and supports all walls and columns. Suitable- soft clay or marshy land or in case of chances of differential settlement
- 42. Grillage Foundation – Grillage foundation is a special type of isolated footing and it is provided for heavily loaded steel stanchions. The depth of foundation is 1 to 1.5m Suitable- if soil have low bearing capacity
- 43. Inverted Arch Foundation this is either in brick or stone & built between two walls, Suitability- at soft soil
- 44. Pile Foundation-Pile foundations are deep foundations used when the site has a weak shallow bearing strata making it necessary to transfer load to a deeper strata either by friction or end bearing principles. Pile are formed by long slender columnar elements.
- 45. Classification based on load transmission: End bearing piles (Point bearing) These transmit most of their loads to the load bearing layer (which can be dense sand or rock). Most of the pile capacity is inferred from the end bearing point. Frictional Piles These transmit their load through the layers through which the piles pass which is mostly through the surface friction (skin friction) with the surrounding soils. End bearing piles Frictional Piles
- 46. Under reamed piles These are bored cast-in-situ concrete piles having one or more number of bulbs formed by enlarging the pile stem. These piles are best suited in soils where considerable ground movements occur due to seasonal variations, filled up grounds or in soft soil strata.
- 47. Classification based on Material of Piles Construction: Timber piles: Timber can be used for manufacture of temporary piles and also for permanent ones in regions where timber is readily and economically available. It’s most suitable for long cohesion piling and piling under embankments. Steel piles: Steel can be used for both temporary and permanent works. They are suitable for handling and driving for piles with prolonged lengths. there may occur a risk of corrosion which can be eliminated by tar coating or cathodic protection.
- 48. Well foundation Well foundation is a type of deep foundation which is generally provided below the water level for bridges. Cassions or well have been in use for foundations of bridges and other structures since Roman and Mughal periods.