Monday, 31 August 2009

What does PN stands for, and what does it mean to be PN-16, PN-12 or PN-20?

PN stands for Nominal Pressure, it is numerical designation used for reference purpose related to mechanical characteristics of the component of a piping system.

PN-25 Pipe means the pipe can withstand pressure Up to 25 bars

  • PN 10 / 12.5 - Cold water distribution and floor heating systems
  • PN 16 - Higher pressure cold water distribution and Domestic Hot Water systems at lower Pressures
  • PN 20 - Hot water distribution systems, central
  • PN-25 –High pressure Hot water Distribution for longer period

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What is DIN standard?

Deutsches Institut für Normung (DIN) is German institute for standardization, it is a technical and scientific association recognized by the German government as the national Standards body representing German interests at International and European levels.

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Wednesday, 12 August 2009

What is Gabbro aggregate?

When going through a specification I found this;

Coarse Aggregate for Concrete

"Coarse aggregate shall be crushed or un crushed gravel, crushed or uncrushed stone complying with BS 882, however for piles, pile caps, columns and walls the aggregates should be Gabbro aggregate to BS 882."

What is Gabbro aggregate?

Gabbro is any of several medium- or coarse-grained rocks that consist primarily of plagioclase feldspar and pyroxene. Gabbro is dense material.

Why it’s using for concrete?

Gabbro aggregate used concrete is highest compressive and flexural tensile strength and abrasion resistance than other aggregate used concrete. Then engineers are recommending to uses gabbro aggregates for the concrete where high compressive/ tensile strength required, like piles, columns and walls.

There is a research regarding “The influence of aggregate type on the strength and abrasion resistance of high strength concrete”. According to the research Gabbro concrete showed the highest compressive and flexural tensile strength and abrasion resistance

Other uses

Ocellar varieties of gabbro can be used as ornamental facing stones, paving stones and it is also known by the trade name of 'black granite', which is a popular type of graveyard headstone used in funerary rites. It is also used in kitchens and their countertops, also under the misnomer of 'black granite'.

Monday, 10 August 2009

How to add a Water mark in to PDF document

I have to prepare a BOQ and need to send it to the client as a Draft BOQ in PDF format. Every page should be a water mark as “DRAFT”.
BOQ prepared by using MS Excel 2007. There is a way to insert a water mark to excel as follow

1) Office button – Print

2) Go to the properties

3) In property there is a tab as “Effect”

4) Under effect you can select DRAFT from “water mark” drop down list box.

5) Click OK

After I insert a water mark in that way, all print outs are with a water mark as “DRAFT”, but when I convert the document in to PDF format the water mark couldn’t appeared.

I found a one way to it. It’s insert a “WordArt”

1) Insert – WordArt and insert a WordArt as Draft

2) Click on “Drawing tool “

3) Made “Text out line” color as Automatic

4) Made the “Text fill” as No fill

5) Double Click on the arrow located below the label “Text effects” and open “Format text effect” box

6) Select “text out line” and reduce the “Transparency “as you want and close

7) Rotate the WordArt as you want

It is not that much appropriate because BOQ is with 200 pages. It’s lot of time consuming method.

Then I try to find a solution from internet. Google give me a good solution. It’s the PDF water mark creator. It is a software (Freeware) for insert a water mark in to PDF documents. I add the water mark to whole document in a one step.

Sunday, 9 August 2009

What is Gunite?

I found a item called "Gunite structure" in a Drawing for a swimming pool. Gunite structure is for the steps to get on to the pool. It also indicated as a blockwork. What is gunite? How to measure it?


Shotcrete is mortar or (usually) concrete conveyed through a hose and pneumatically projected at high velocity onto a surface. Shotcrete is today an all-inclusive term that describes spraying concrete or mortar with either a dry or wet mix process. However, it may also sometimes be used to distinguish from gunite as a wet-mix. The greatest advantage of the wet-mix process is that larger volumes can be placed in less time.


Gunite refers only to the dry-mix(mixture of Portland cement and sand ) process, in which the dry cementitious mixture is blown through a hose to the nozzle, where water is injected immediately before application.
The dry mix process is useful in repair applications when it is necessary to stop frequently, as the dry material is easily discharged from the hose.
Gunite is extremely strong, dense and highly resistant to weathering and many forms of chemical attack. It is heat resistant to a high degree

Measurements :

According to the Drawings gunite structure is over the blockwork and mosaic tile finish is fixed to gunite using adhesive.

1) Blockwork
Measured as blockwork in metre cube (m3) and billed in Blockwork bill.

2) Gunite
Measured in squre metre (m2) as backing to mosaic tile and billed in finishes bill.

3) Mosaic tile
Measured in squre metre (m2) as mosaic tile and billed in finishes bill.

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