structural-steel-8768

1. A presentationon StructuralSteel

2. Steel Man made metal derived from iron- which is its major constituent Remaining components are small amounts of otherelements Added to improve the quality of steel   

3. Used as: Basic products of steel mill suchas plate, section andbars From this members are fabricated viz. beams, girders, columns, struts, ties etc.  

4. Steelvs. CastIron Up to 1.5 % Carbon combines withiron More than 1.5 -4.5 % present asfree graphite –knownas castiron Properties vary with the varying carbon content Increasing carbon content produces increase in shear strength&hardness Decreases the ductilityandtoughness     

5. Comparison between Cast Iron, Wrought Iron& Steel CastIron Wroughtiron Steel Purest Contains upto 0.25%carbon composition Crude form containing 2-4%carbon Midway Meltingpoint 1200 degreeCelsius 1500degree Celsius 1300-1400degree Celsius Hardness Hard, hardenedby heating & sudden cooling Cannot be hardenedor tempered Can be hardened& tempered Strength Comp.strength 6.3-7.1 tonnes/sqcm Ultimate tensile strength 1.26 to 1.57tonnes/sqcm. compressive strength is 2.0 tonnes/sq cmand ultimate tensile strength 3.15 tonnes/sqcm Compstrength 4.75 -25.2tonnes/ sq cm Ultimate tensile strength is 5.51to 11.02 t /sqm

6. Comparison between Cast Iron, Wrought Iron & Steel CastIron Wroughtiron Steel Rusting Does notrust easily Rusts morethan CastIron Rustseasily Malleability&Duct ility Brittle & cannot be welded or rolled intosheets Tough, malleable,ductile & moderately elastic Tough,malleable & Ductile Reaction to suddenshock Does notabsorb shocks Cannotstand heavyshocks Absorbsshocks Forging& Welding Brittle and cannot be welded orrolled intosheets Easily forgedor welded Rapidly forgedor welded

7. Comparison between Cast Iron, Wrought Iron &Steel CastIron Wroughtiron Steel Uses For parts that rust easily like water pipes, sewers,drain pipesetc. Making such parts of machines as are not likelyto be subjects to shocks or tension Lamp posts, columnsand railings Costlier than mild steel so beingreplaced by thelatter Withstand shockswithout permanent injury so used in chains, crane hooks and railway couplings Used as reinforcemen t in R.B. & R.C.C. Used inmaking St. members, bolts, rivets and sheets (plain and corrugated) Making cutlery,files & machine tools

8. Types of Steel: (According to varying CarbonContent) Dead Mild Steel (Less than 0.15 % Carbon) Mild Steel (0.15 – 0.30 %Carbon) Medium Carbon Steel (0.30 -0.80 % Carbon) High Carbon Steel (0.80 -1.50 % Carbon) Cast Steel / Carbon Tool Steel (Morethan 1.50 % Carbon)     

9. MildSteel Ductile &malleable More tough and more elastic than cast iron and wrought iron More prone to rusting than wrought iron Corrodesquickly Easily forged, welded & riveted Withstands shocks & impacts well Not much affected by salinewater Equally strong in tension, compression and in shear Difficult to harden and temper Sp. Gravity7.8          

10. MildSteel :Uses Used as rolled structural sections like I- section; T-section; channel Section; angle irons. Plates round and squarerods M.S. Roundbars Used as reinforcement inR.C.C. M.S. tubes are used instructures Plain and Corrugated M.S. Sheets are used in roofing     

11. Medium CarbonSteel Granularstructure More tough & elastic than M.S. Easier to harden & totemper More difficult to to forge and to weld Stronger incompressionthan in tension orin shear Withstands shocks and vibrationsbetter      

12. Medium Carbon Steel :Uses For making tools such as dills, files, chisels Used for making those parts that ae hard , tough and durable and capable of withstanding shocks and vibrations  

13. High CarbonSteel Increased tensile strength leads to less weight of it being used as comparedto M.S. Structure becomes lighter Resists corrosionbetter Tougher and more elastic More brittle and less ductile than mild steel     

14. High Carbon Steel :Uses Inreinforcing prestressedconcrete structures 

15. Types of Steel: (according to elementsused) Steels that owe their properties due to carbon are called CarbonSteels Steels with properties due to elements other than carbon are termed as Alloy Steels  

16. AlloySteels The elements that impart distinctive characteristics to steel are added to iron to produce an alloy steel named after the elementadded Prepared to increase strength, hardness, toughness, resistance to corrosion and thermal and electrical conductivities   Divided into twocategories: • Ferrous alloys ( chromium, nickel, vanadium, tungsten, molybdenum and manganese) • Non Ferrousalloys 

17. Stress straincurve

18. Structural steel sections Hot rolledsections

19. Tolerances in structuralsteel It is not possible in rolling process to produce sections to the exact dimensionsspecified. Allowancesfor:  • Slight variation in member length Inaccurate location ofholes • Out of squareness of member ends Variation in depth of welded girders Other dimensionalvariations    

20. bolting Most common method in joining structural isbolting:

21. welding There are 3 differenttype ofwelds • Butt weld Filletweld Lapweld  

22. Properties of a structural steel frame Indesign: Large spans With columns of smallsections Great building heights and high loadbearing capacity Combined with low dead weight of the structure Structural systems in which openings can be easilyprovided To simplify installation ofservices      

23. Properties of a structural steel frame Inconstruction: • Prefabrication and erection of components Shorter constructiontime • Close dimensional tolerances Ease in fixing andcladding • Erection independent of weather conditions Modest demand on space on thesite • Dry construction      

24. Properties of a structural steel frame Inuse: • Greaterflexibility • Limited no. of internalsupports • Adaptibility of frame work to change of use • Increasing effective life of building Ease in dismantling ordemolition    

25. 1. Portal Frame -Rafter Portal Frame -Column Windbracing Purlins WallRails Roofpanels Wallpanels Astrotherminsulation Eave gutter Monovent Applications Circularvent Vehicle door Pedestrian door Window Roof light Canopy Parapet Crane beams andrails Bridgecrane 20. Mezzanine or StructuralFloor

26. Applications: WindBracing Wind bracing provides the longitudinal stability of thebuilding. It consists of cross bracing located in roof and sidewalls, in one or more bays depending on loadings and the length of thebuilding. If it is not possible to have cross bracing in the sidewalls, it can be replaced by wind portal frames or by fixed base wind columns, located adjacent and connected to the mainframecolumns.   

27. Applications: RoofLights Roof Lights can be of dome constructionas  shown here or as profiled sheets replacing steel roof panels. Function Continuous naturallight GeneralCharacteristics Insulated roofcurb A framed opening of double skin metallic roof curb, to match the profile of the roof sheet and its location. Class-fibre insulation is installed on job site.   

28. Applications:Astrotherm insulation Astrotherm insulation consists of fibre glass blanket complete with a laminated facingvapour barrier Optionally, isoblocks are supplied to minimise thermal bridges and Alustrip to improve the overall appearance ofany exposed insulationjoints.  

29. Eavegutter Gutters are often an afterthought and can spoil the appearance of abuilding The gutters are large capacity and colour coated to compliment the building. Alternatively internal gutters can beprovided  

30. Monovent Used On the peak in the roofs Function Ventilation of the building at the ideal peak position, where large movement of air is required. General Characteristics Steel operating cable, cable guides (instead of standard type pulleys), hook and cable stop. Stainless steel screws and aluminiu rivets.    m 

31. RoofPanels

32. Wall Panels

33. Mezzanine

34. Purlins

35. Bridgecrane

36. CircularVents

37. Pedestriandoor

38. Structural steel in buildings Airport terminalcomplex

39. A steel joist and king post truss system provide support for the 650,000sq. ft.roof.

40. This framing system creates wide-open, column-free spaces king post trusses form the lateral-force resisting system, eliminating the need for bracing andfurther increasing flexibility of the interiorspace.

41. Steel buildings-stadium

42. The upper tier, cantilevering 46' over the suite and club Levels supported by column groupings consisting of four massive steel HSS placed at the midpoint alternating structural bays.