Monday, June 20, 2011

DERIVATION FOR D2/162

We know the formula D2/162 which is being used for calculate unit weight of reinforcement per meter.
Here I am willing to explain how it has been arrived D2/162 (Note: D unit is in MM)
Weight of bar per meter = Area of steel bar X Density of steel x Length of bar
= (3.14 x D2/4) x 7850 kg/m3 x 1 m
= D2 X 6162.25/(1000x1000)
= D2 X (0.006162)
= D2 X 1/(0.006162)-1
= (D2/162.28)

The actual value is D2/162.28

Kindly note that this function is only applicable for circular shape steel which density is 7850kg/m3

18 comments:

  1. Hello sir,
    why the value 0.006212 is converted into 1/.006212-1.
    please tell me.

    ReplyDelete
    Replies
    1. bro it not -1... its to the power -1

      Delete
    2. I understand that it is the inverse but why are we taking the inverse of 0.00616225 D2 is to only get 162 for the ease of saying it as a whole number?

      Delete
    3. It is just for simplicity in calculation

      Delete
    4. 0.00612 is equals to 1/(0.00612)^-1

      You can easily use both formulas like D2/162 or D2x0.00612

      Delete
  2. I don't understand after D2 X 1/(0.006162)-1.

    How it comes D2/162.28????

    ReplyDelete
    Replies
    1. its not-1... its (1/0.006162) to the power -1

      Delete
    2. its not-1... its (1/0.006162) to the power -1

      Delete
  3. D2 X 6162.25/(1000x1000)

    Why do we have to divide 1000 twice plz explain

    ReplyDelete
    Replies
    1. the unit weight of steel is 7850 kg / m^3
      but we are dealing in mm here so this m3 gets converted into 1000mm multiplied 3 times but see we have mass/unit length on the other side of the equation as well, so shifting unit length on other side of equations gets cancelled with 1ooomm , thus we are left with 2 times 1000mm.
      7850kg/(1000*1000*1000) * 3.14 D^2/4 * 1000MM (UNIT LENGTH) = MASS OF STEEL BAR

      Delete
    2. the unit weight of steel is 7850 kg / m^3
      but we are dealing in mm here so this m3 gets converted into 1000mm multiplied 3 times but see we have mass/unit length on the other side of the equation as well, so shifting unit length on other side of equations gets cancelled with 1ooomm , thus we are left with 2 times 1000mm.
      7850kg/(1000*1000*1000) * 3.14 D^2/4 * 1000MM (UNIT LENGTH) = MASS OF STEEL BAR

      Delete
    3. Weight of the bar for 1 m
      = volume × density
      = πxd^2/4 x 1m×7850kg/m3
      Converting M to MM
      = D^2 × 3.14/4 × 1000 × 7850/(1000^3)
      = D^2/162

      Delete
  4. Not clear D2/0.006162 convert in D2/162.28

    ReplyDelete
    Replies
    1. D2×0.006162=D2/(0.006162)-1 =D2/162.28. Now clear

      Delete
  5. Click here and learn full explanation step by step
    http://civilengineering112.blogspot.com/2017/08/derivation-of-d162-unit-weight-of.html

    if you like read more in civil engineer ( in your language click here )

    http://civilengineering112.blogspot.com

    ReplyDelete
  6. Nice information. Here SAIL TMT Bar have higher strength and ductility for safer construction. It will be available in the length of 12 meters initially in sizes with 8mm-20mm diameter

    ReplyDelete