# RE: Low Concrete Quality...Metric Units

• To: seaint(--nospam--at)seaint.org
• Subject: RE: Low Concrete Quality...Metric Units
• From: Steven Mallett <smallett(--nospam--at)dillon.ca>
• Date: Mon, 18 Jun 2001 11:09:22 -0400
```Just to add a few points regarding the metric system from my
perspective. A kg is a unit of mass while a Newton is a unit of force
representing 1 kg x 9.81 metre/sec2 (9.81 being gravitational
acceleration, not 1).  Thus, 1 kg mass weighs 9.81N, at least on Earth.

Similarly, in the imperial system, a slug is a unit of mass while a pound is
a unit of force representing 1 slug x 32.2 feet/sec2 (gravity). While we
buy meat and other food by the metric mass (kilogram), I am guessing
there would be some resistance by those in the food industry to using
the imperial measure of mass, i.e slugs.

My two cents,

Steven A. Mallett, P.Eng.
Dillon Consulting Ltd.
Halifax, Nova Scotia

-----Original Message-----
From: "Lutz, James" <JLUTZ(--nospam--at)earthtech.com>
To: seaint(--nospam--at)seaint.org
Subject: RE: Low Concrete Quality

I think my unstated point was that the units made no sense. Compressive
strength is measured in units of pressure, or force per unit area, not
mass
per unit area. A kilogram is a unit of mass. A Newton is a unit of force
equal to a kilogram times an acceleration of 1 meter/sec2.

As we used to say in Alaska, "I don't care how they do it down south."

-----Original Message-----
From: Oshin Tosounian [mailto:sdgse(--nospam--at)pacbell.net]
Sent: Friday, June 15, 2001 10:35 AM
To: seaint(--nospam--at)seaint.org
Subject: Re: Low Concrete Quality

-----Original Message -----
From: "Lutz, James" <JLUTZ(--nospam--at)earthtech.com>
To: <seaint(--nospam--at)seaint.org>
Sent: Friday, June 15, 2001 8:41 AM
Subject: RE: Low Concrete Quality

> I've never heard of compressive strength being expressed as kg/cm2.
> Shouldn't it be N/cm2 or MPa? 210 N/cm2 or 21 Mpa is around 3000 psi.
(1
Ksi
> = 6.894 MPa.)
>

Kg/cm2 is part of the metric system used in some countries. The others
you
metioned are part of  "System International", which is erroneously (I
think)
referrd to as the metric system.

Oshin Tosounian, S.E.
Los Angeles, CA

*
*   This email was sent to you via Structural Engineers
*   Association of Southern California (SEAOSC) server. To
*   subscribe (no fee) or UnSubscribe, please go to:
*
*   http://www.seaint.org/sealist1.asp
*
*   Questions to seaint-ad(--nospam--at)seaint.org. Remember, any email you
*   send to the list is public domain and may be re-posted