what is portland cement

8/7/2019 What is Portland cement

http://slidepdf.com/reader/full/what-is-portland-cement 1/11



Cement

type

Use

I General purpose cement, when there are no

extenuating conditions

II Aids in providing moderate resistance to

sulfate attack

III When high-early strength is required

IV When a low heat of hydration is desired (in

massive structures)

V When high sulfate resistance is required

IA A type I cement containing an integral air-

entraining agent

IIA A type II cement containing an integral air-

entraining agent

IIIA A type III cement containing an integral air-

entraining agent

What is the difference between Rapid-hardening Portland cement

and ordinary Portland cement?

Rapid-hardening Portland cement is more finely ground and its

gains its working strength earlier.

Where should this cement stored?Cement must store on a damp proof floor in the dark and kept for

short periods only. Air hardening (cement will harden the action of

moisture in the air) will happen if cement kept for long periods. Hardened

cement cannot be used again.



How Portland cement produced?

Portland cement can be produced by two processes which are wet

process and dry process.

Wet Process

Dry Process (Main difference between this and wet process is less waterused in the kiln)

Two raw materials are washed, broken up and mixed with water to form a slurry.

Slurry is pumped into steel rotary kiln and lined with refractory bricks. Slurry is

assin down the kiln which is about 1400 Celsius to ive u the moisture.

Then the chalk or limestone is broken down into carbon dioxide and lime and itforms a white-hot clinker, which transfers to a cooler before being ground.

The grinding is carried out in a ball mill which containing a large number of steel

balls of various sizes, which grind the clinker to a fine powder. Gypsum (about

5% is added to revent a flash settin off the cement.

A mixture of limestone and shale is used, which is proportioned, ground and

blended to form a raw meal of low moisture content.

The meal is granulated in rotating plans with little water before passing it to a

grate for preheating.

Then it enters into the kiln to give up its moisture. The kiln is smaller. It will

break down and form the clinker the rocess almost same with wet rocess .

After that it is cooled, grounded, and mixed with a little gypsum.(as described

for the previous process)



Typical clinker nodules Cement kiln

A 10 MW cement mill, producing cement at

270 tonnes per hour



Schematic explanation of Portland cement production



Part of nail.

What is nail?

Nail is a sharp object of hard metal or alloy with the sharp point at

one end.

What is the finishes, coatings, or material of nail?

Nail can be bright, cement coated, galvanised, stainless steel or

aluminum.

Bright finish-do not has any protection and most economical choice. But

the nail will rust before the protective treatment.

Galvanised nail-galvanizing or coated with zinc, the best way to prevent

the corroding. The zinc will corrode first before the nail rusts.

Stainless steel nail-provide maximum protection. For example: stainlesssteel nails are ideal motorway fencing where a fasteners life is very

important or in applications which are exposed to salt water.

Aluminium nail-it is a softer material, reducing the impact on the saw

blades and machinery of the joiner/ manufacturer. It offer better rust

resistance than galvanised nail. It uses for specialized tasks like

mounting light in swimming pool.



What is the size of the nails?

In most of the world, nails are described by their dimensions in

millimeters, for example 150 × 4 is a nail 150 mm long and 4 mm in

diameter. A description of the head and finish is typically added. In

United States, the length of a nail is designated by its penny size. Thelarger nail has the larger number for its penny size. The penny size is

written with a number and the abbreviation d for penny (e.g. - 10d).

What is the use of the nail?

The nail can be used as fastener, to hold two pieces of wood

together. Besides, nail also essential in most of the woodworkingenterprises. Nail also holds the things when it knocks into the wall.

What are the tools used with nail?

Hammer, pneumatic nail gun or small explosive charge or primer.

Types of nails , their uses and their sizes?

1. Round wire nailThese round head nails are mostly used for rough carpentry

where appearance is not important but strength is required.

Size ~ 20-150mm



2. Oval wire nail

For joinery work where appearance is important since they can

punch below the surface easily.Size~12-150mm

3. Round or lost head nail

Stronger than oval wire nail. It can punch below the surface.

Size~12-150mm

4.

Tack

Short nail with flat, wide head. Tack is used for fixing carpets to

floorboards and for stretching fabric on to wood.

5.

Panel pin

Used for cabinet making and for fixing small molding into place.

6. Cut floor bradRectangular and have L-shape head. Used to nail floorboards to

joists. Size~25-150mm

7.

Masonary nail

Made of hardened steel. Used to fix wood to brick, breeze block

and most types of masonry.

8. Annular nail

Give the strong joists. The sharp ridges round the shank become

embedded in the wood to give a tight grip.



9.

Spring-head roofing nailFor fixing corrugated sheeting to timber. The twisted shank and

inverted cup head produces a very strong purchase.

10. Cut clasp nail

Rectangular in section. Provide strong fixing with wood and

predrilled masonary. Size~25-150mm

11.

Sprig

A small nail without a head. Used mainly to hold glass in

window frames before applying putty which covers them up.

Sizes from 12-19mm

12.

Staple.

U-shaped round wire nails with two points to hold lengths of

wire in position.

13.

Corrugated fastener

It will hold the corners of wood frames firmly together.

Typical use of nailing

The nails are angled towards each other and this makes it a little more

difficult for the two pieces of wood to be pulled apart. A punch can then be

used to tap the heads of the nail slightly below the surface of the wood.



What is paint brush?

The equipment which carries the paint to the surface that has to be

painted.

What are the two basic types of paint brushes?

Natural bristle type and synthesis bristle type

Natural bristle type- Suitable for oil based or the alkyd types of paint.

Not suitable for latex type paint. Natural bristle

type is made from hair of squirrel, ox, goat,

pony or camel.

Synthesis bristle type- Made for all types of coatings. Everything from

oil, to primers, to latex paint, these brushes

are ideal for the casual painter who simply

might want to paint a cabinet, or some

bedroom walls over a long weekend, and then

throw it away, or put it in storage for later use.

Is natural hair better than synthesis?

Modern synthetic brushes are excellent and cheaper than natural

hair. Natural hair is flexible and strength enough. So, choose the brushes

depend on your needs.

What are additional tools used with paint brush?

Paint edger, corner painter, trim& touch-up Pad, Pad painter, and

Foam brush.



Sizes of the paint brush

1. 1-for use in narrow places 2. 2-for use with trim and sash

3. 3-wall brush 4. 4-wall brush ( for painting exterior

siding and trim)

The uses of soft brush and hard brush.Soft brush- for thin paint which spreads easily, and for detailed work

as they form a sharp point which allows for precision

painting.

Robust,hard- pushing around thick paint and for creating brush

brush marks in the paint.

what is portland cement

Documents