CONSTRUCTION TECHNOLOGY - 3

SUBMITTED BY:DEVASHISH SONI

UC5711

SUBMITTED TO:

PROF. S. SAPRE

Fabrication methods

Shop drawing, material requirement and procurement

Cutting Straightening Welding Assembling Finishing Filing, grinding, machining Punching, drilling Bending Slicing painting

Cutting

Laser Plasma Oxy acetylene Oxy LPG Shearing

LASER› For industrial setup

› Laser cutting is a technology that uses a laser to cut materials, and is typically used for industrial manufacturing applications. Laser cutting works by directing the output of a high-power laser, by computer, at the material to be cut.

› The material then either melts, burns, vaporizes away, or is blown away by a jet of gas, leaving an edge with a high-quality surface finish.

› Industrial laser cutters are used to cut flat-sheet material as well as structural and piping materials.

PLASMA CUTTING› Plasma cutting is a

process that is used to cut steel and other metals of different thicknesses (or sometimes other materials) using a plasma torch.

› In this process, an inert gas (in some units, compressed air) is blown at high speed out of a nozzle; at the same time an electrical arc is formed through that gas from the nozzle to the surface being cut, turning some of that gas to plasma.

› The plasma is sufficiently hot to melt the metal being cut and moves sufficiently fast to blow molten metal away from the cut.

Oxy fuel cutting

In oxy-fuel cutting, a cutting torch is used to heat metal to kindling temperature. A stream of oxygen then trained on the metal combines with the metal which then flows out of the cut (kerf) as an oxide slag.

Fuels used are acetylene, gasoline, hydrogen etc

Metal cut by oxygen propane torch

Shearing  When a great enough shearing

force is applied, the shear stress in the material will exceed the ultimate shear strength and the material will fail and separate at the cut location.

This shearing force is applied by two tools, one above and one below the sheet.

the tool above the sheet delivers a quick downward blow to the sheet metal that rests over the lower tool.

A small clearance is present between the edges of the upper and lower tools, which facilitates the fracture of the material.

Drilling A drill line has long been

considered an indispensible way to drill holes and mill slots into beams, channels and sections. CNC drill lines are typically equipped with feed conveyors and position sensors to move the element into position for drilling, plus probing capability to determine the precise location where the hole or slot is to be cut.

Punching Punching is a metal

forming process that uses a punch press to force a tool, called a punch, through the work piece to create a hole via shearing. The punch often passes through the work into a die. A scrap slug from the hole is deposited into the die in the process. Depending on the material being punched this slug may be recycled and reused or discarded. Punching is often the cheapest method for creating holes in sheet metal in medium to high production volumes. 

Bending Bending of sheet metal is a

common and vital process in manufacturing industry.

 Sheet metal bending is the plastic deformation of the work over an axis, creating a change in the part's geometry. Similar to other metal forming processes, bending changes the shape of the work piece, while the volume of material will remain the same. In some cases bending may produce a small change in sheet thickness.

bending is also used to impart strength and stiffness to sheet metal

Painting It forms a protective layer over section

hence enhances the life of element It is done due to time lapse between

manufacturing and usage of the element MILL SCALE – thin film of rust is formed

over the section which changes the color of element from metallic to rust

Two stages of painting are1. Surface preparation2. painting

SURFACE PREPARATION

Emery paper Wire brushing

ManualMachine brushing

Acid pickling Sand blasting / metal blasting

Wire brushing The wire brush is

primarily an abrasive implement, used for cleaning rust and removing paint. When cleaning stainless steel, it is advisable to use a stainless steel bristle wire brush, as a plain carbon steel brush can contaminate the stainless steel and cause rust spots to appear.

Acid pickling Pickling is a metal surface treatment used to remove

impurities, such as stains, inorganic contaminants, rust or scale from ferrous meta, copper, and aluminium alloys.

A solution called pickle liquor, which contains strong acids, is used to remove the surface impurities. It is commonly used to descale or clean steel in various steelmaking processes.

The primary acid used is hydrochloric acid, although sulphuric acid was previously more common. Hydrochloric acid is more expensive than sulphuric acid, but it pickles much faster while minimizing base metal loss.

In this method section is lifted with crane and dipped in the acid tank and then kept in clean water tank

Sand blasting

Very fine quartz sand is used for this purpose.

Three equipments used in it are Compressor Pneumatic chamber Pipe

Sand is sprayed on the surface with very high pressure to give smooth finish.

Types of painting

Roller Brushing Spraying Metalizing Hot dip galvanizing two layers are applied on surface base

layer and finishing layer Alcometer is a digital instrument

measuring the paint thickness in microns

Erection

Derrick pole Cranes

TelescopicTowersGoliath

ToolsPulleywinches

Derrick

A derrick is a lifting device composed of one tower, or guyed mast such as a pole which is hinged freely at the bottom.

It is controlled by lines (usually four of them) powered by some means such as man-hauling or motors, so that the pole can move in all four directions.

Tower crane Telescopic crane

Goliath crane

Winches Can be manually

operated or motorized A winch is a mechanical

device that is used to pull in (wind up) or let out (wind out) or otherwise adjust the "tension" of a rope or wire rope

ACCESORIES

Shackles- for wire connectionsDee shackleBow shackleTemporary or

permanent clamping

GripBull dog gripTurn buckle

DEE SHACKLE

BOW SHACKLE

TURN BUCKLES

CONCRETE SHELL ROOFS IN

INDUSTRIAL BUILDINGS

ADVANTAGES OF CONCRETE SHELL ROOFS

It is a thin membrane element. It has a thin slab. Better in corrosive environment. Gives better cooling. Better fire resistance.

Types of concrete shell roofs

Cylindrical shell Trapezoidal shell ‘V’ shell Hyperbole shell Parabolic shell Hyper/umbrella shell Pyramid shell

Cylindrical shell

It has very less slab thickness. M25 , M30 grade concrete used. Beam span is larger.

TRAPEZOIDAL CONCETE SHELL ROOF

‘V’ type shell

HYPERBOLIC/PARABOLIC shell

INVERTED UMBRELLA

SQUARE DOME SHELL ROOF

BARREL vault shell roof

THANK YOU...