OT. Roman Concrete...

[Dean Hoffman]

New vs. Better.
Scientists think they know why the Pantheon is still standing after 2,000 years.
<https://www.cnn.com/style/article/roman-concrete-mystery-ingredient-scn/index.html>
There must be examples of new not being better in the electrical field.

 

[Fred Bloggs]

On Sunday, January 8, 2023 at 2:33:07 PM UTC-5, lang...@fonz.dk wrote:

søndag den 8. januar 2023 kl. 20.03.34 UTC+1 skrev Fred Bloggs:
On Sunday, January 8, 2023 at 10:13:23 AM UTC-5, dean...@gmail.com wrote:
New vs. Better.
Scientists think they know why the Pantheon is still standing after 2,000 years.
https://www.cnn.com/style/article/roman-concrete-mystery-ingredient-scn/index.html
That stuff about the quicklime slurry seems to be a departure from what they\'ve always known about Roman concrete, and that is it was very dry. It is estimated Roman concrete was only 10-15 % water by weight, it was not pourable and had to be muscled into place by pounding. Modern formulation is 20-30 % water by mass and is significantly weaker upon cure than the dry mix, but, the convenience, if not the necessity, of being able to pour it into forms is more important.
Modern technology has found a better substitute for pozzuoli in the form of fly ash captured from coal burning.
\"modern\", the cement here factory have been using fly ash from the neighboring coal fired power plant since 1978 ..

That\'s pretty modern compared to 250 BC.

 

[Fred Bloggs]

On Sunday, January 8, 2023 at 2:33:07 PM UTC-5, lang...@fonz.dk wrote:

søndag den 8. januar 2023 kl. 20.03.34 UTC+1 skrev Fred Bloggs:
On Sunday, January 8, 2023 at 10:13:23 AM UTC-5, dean...@gmail.com wrote:
New vs. Better.
Scientists think they know why the Pantheon is still standing after 2,000 years.
https://www.cnn.com/style/article/roman-concrete-mystery-ingredient-scn/index.html
That stuff about the quicklime slurry seems to be a departure from what they\'ve always known about Roman concrete, and that is it was very dry. It is estimated Roman concrete was only 10-15 % water by weight, it was not pourable and had to be muscled into place by pounding. Modern formulation is 20-30 % water by mass and is significantly weaker upon cure than the dry mix, but, the convenience, if not the necessity, of being able to pour it into forms is more important.
Modern technology has found a better substitute for pozzuoli in the form of fly ash captured from coal burning.
\"modern\", the cement here factory have been using fly ash from the neighboring coal fired power plant since 1978 ..

That\'s pretty modern compared to 250 BC.

 

[Fred Bloggs]

On Sunday, January 8, 2023 at 2:33:07 PM UTC-5, lang...@fonz.dk wrote:

søndag den 8. januar 2023 kl. 20.03.34 UTC+1 skrev Fred Bloggs:
On Sunday, January 8, 2023 at 10:13:23 AM UTC-5, dean...@gmail.com wrote:
New vs. Better.
Scientists think they know why the Pantheon is still standing after 2,000 years.
https://www.cnn.com/style/article/roman-concrete-mystery-ingredient-scn/index.html
That stuff about the quicklime slurry seems to be a departure from what they\'ve always known about Roman concrete, and that is it was very dry. It is estimated Roman concrete was only 10-15 % water by weight, it was not pourable and had to be muscled into place by pounding. Modern formulation is 20-30 % water by mass and is significantly weaker upon cure than the dry mix, but, the convenience, if not the necessity, of being able to pour it into forms is more important.
Modern technology has found a better substitute for pozzuoli in the form of fly ash captured from coal burning.
\"modern\", the cement here factory have been using fly ash from the neighboring coal fired power plant since 1978 ..

That\'s pretty modern compared to 250 BC.

 

[Fred Bloggs]

On Sunday, January 8, 2023 at 10:13:23 AM UTC-5, dean...@gmail.com wrote:

New vs. Better.
Scientists think they know why the Pantheon is still standing after 2,000 years.
https://www.cnn.com/style/article/roman-concrete-mystery-ingredient-scn/index.html

That stuff about the quicklime slurry seems to be a departure from what they\'ve always known about Roman concrete, and that is it was very dry. It is estimated Roman concrete was only 10-15 % water by weight, it was not pourable and had to be muscled into place by pounding. Modern formulation is 20-30 % water by mass and is significantly weaker upon cure than the dry mix, but, the convenience, if not the necessity, of being able to pour it into forms is more important.
Modern technology has found a better substitute for pozzuoli in the form of fly ash captured from coal burning. A drawback is not all fly ash is created equal and it must be analyzed before use to determine optimum admixtures.. What they do know is it cures to a much stronger product than concrete without it, and it takes 3-6 months for the cure to reach final strength.
The materials geeks missed the structural engineering part of the Pantheon that probably contributed the most to its longevity. The Romans graded their aggregate with height, using heavier higher load bearing capacity concrete at lower heights, and finishing off the dome with much lighter mostly fine sand aggregate at the dome where load bearing capacity was not as critical.

> There must be examples of new not being better in the electrical field.

 

[Fred Bloggs]

On Sunday, January 8, 2023 at 10:13:23 AM UTC-5, dean...@gmail.com wrote:

New vs. Better.
Scientists think they know why the Pantheon is still standing after 2,000 years.
https://www.cnn.com/style/article/roman-concrete-mystery-ingredient-scn/index.html

That stuff about the quicklime slurry seems to be a departure from what they\'ve always known about Roman concrete, and that is it was very dry. It is estimated Roman concrete was only 10-15 % water by weight, it was not pourable and had to be muscled into place by pounding. Modern formulation is 20-30 % water by mass and is significantly weaker upon cure than the dry mix, but, the convenience, if not the necessity, of being able to pour it into forms is more important.
Modern technology has found a better substitute for pozzuoli in the form of fly ash captured from coal burning. A drawback is not all fly ash is created equal and it must be analyzed before use to determine optimum admixtures.. What they do know is it cures to a much stronger product than concrete without it, and it takes 3-6 months for the cure to reach final strength.
The materials geeks missed the structural engineering part of the Pantheon that probably contributed the most to its longevity. The Romans graded their aggregate with height, using heavier higher load bearing capacity concrete at lower heights, and finishing off the dome with much lighter mostly fine sand aggregate at the dome where load bearing capacity was not as critical.

> There must be examples of new not being better in the electrical field.

 

[Fred Bloggs]

On Sunday, January 8, 2023 at 10:13:23 AM UTC-5, dean...@gmail.com wrote:

New vs. Better.
Scientists think they know why the Pantheon is still standing after 2,000 years.
https://www.cnn.com/style/article/roman-concrete-mystery-ingredient-scn/index.html

That stuff about the quicklime slurry seems to be a departure from what they\'ve always known about Roman concrete, and that is it was very dry. It is estimated Roman concrete was only 10-15 % water by weight, it was not pourable and had to be muscled into place by pounding. Modern formulation is 20-30 % water by mass and is significantly weaker upon cure than the dry mix, but, the convenience, if not the necessity, of being able to pour it into forms is more important.
Modern technology has found a better substitute for pozzuoli in the form of fly ash captured from coal burning. A drawback is not all fly ash is created equal and it must be analyzed before use to determine optimum admixtures.. What they do know is it cures to a much stronger product than concrete without it, and it takes 3-6 months for the cure to reach final strength.
The materials geeks missed the structural engineering part of the Pantheon that probably contributed the most to its longevity. The Romans graded their aggregate with height, using heavier higher load bearing capacity concrete at lower heights, and finishing off the dome with much lighter mostly fine sand aggregate at the dome where load bearing capacity was not as critical.

> There must be examples of new not being better in the electrical field.

 

[Don Y]

On 1/8/2023 8:13 AM, Dean Hoffman wrote:

New vs. Better.
Scientists think they know why the Pantheon is still standing after 2,000 years.
https://www.cnn.com/style/article/roman-concrete-mystery-ingredient-scn/index.html
There must be examples of new not being better in the electrical field.

Sure! The fact that things aren\'t designed to be repaired
(or diagnosed) anymore.

User interfaces, in general, have become more *capable*, yet
harder to use (even things with knobs often have *tiny* knobs
and tiny legends).

 

[Don Y]

On 1/8/2023 8:13 AM, Dean Hoffman wrote:

New vs. Better.
Scientists think they know why the Pantheon is still standing after 2,000 years.
https://www.cnn.com/style/article/roman-concrete-mystery-ingredient-scn/index.html
There must be examples of new not being better in the electrical field.

Sure! The fact that things aren\'t designed to be repaired
(or diagnosed) anymore.

User interfaces, in general, have become more *capable*, yet
harder to use (even things with knobs often have *tiny* knobs
and tiny legends).

 

[Don Y]

On 1/8/2023 8:13 AM, Dean Hoffman wrote:

New vs. Better.
Scientists think they know why the Pantheon is still standing after 2,000 years.
https://www.cnn.com/style/article/roman-concrete-mystery-ingredient-scn/index.html
There must be examples of new not being better in the electrical field.

Sure! The fact that things aren\'t designed to be repaired
(or diagnosed) anymore.

User interfaces, in general, have become more *capable*, yet
harder to use (even things with knobs often have *tiny* knobs
and tiny legends).

 

[Lasse Langwadt Christensen]

søndag den 8. januar 2023 kl. 20.03.34 UTC+1 skrev Fred Bloggs:

On Sunday, January 8, 2023 at 10:13:23 AM UTC-5, dean...@gmail.com wrote:
New vs. Better.
Scientists think they know why the Pantheon is still standing after 2,000 years.
https://www.cnn.com/style/article/roman-concrete-mystery-ingredient-scn/index.html
That stuff about the quicklime slurry seems to be a departure from what they\'ve always known about Roman concrete, and that is it was very dry. It is estimated Roman concrete was only 10-15 % water by weight, it was not pourable and had to be muscled into place by pounding. Modern formulation is 20-30 % water by mass and is significantly weaker upon cure than the dry mix, but, the convenience, if not the necessity, of being able to pour it into forms is more important.
Modern technology has found a better substitute for pozzuoli in the form of fly ash captured from coal burning.

\"modern\", the cement here factory have been using fly ash from the neighboring coal fired power plant since 1978 ..

 

[Lasse Langwadt Christensen]

søndag den 8. januar 2023 kl. 20.03.34 UTC+1 skrev Fred Bloggs:

On Sunday, January 8, 2023 at 10:13:23 AM UTC-5, dean...@gmail.com wrote:
New vs. Better.
Scientists think they know why the Pantheon is still standing after 2,000 years.
https://www.cnn.com/style/article/roman-concrete-mystery-ingredient-scn/index.html
That stuff about the quicklime slurry seems to be a departure from what they\'ve always known about Roman concrete, and that is it was very dry. It is estimated Roman concrete was only 10-15 % water by weight, it was not pourable and had to be muscled into place by pounding. Modern formulation is 20-30 % water by mass and is significantly weaker upon cure than the dry mix, but, the convenience, if not the necessity, of being able to pour it into forms is more important.
Modern technology has found a better substitute for pozzuoli in the form of fly ash captured from coal burning.

\"modern\", the cement here factory have been using fly ash from the neighboring coal fired power plant since 1978 ..

 

[Lasse Langwadt Christensen]

søndag den 8. januar 2023 kl. 20.03.34 UTC+1 skrev Fred Bloggs:

On Sunday, January 8, 2023 at 10:13:23 AM UTC-5, dean...@gmail.com wrote:
New vs. Better.
Scientists think they know why the Pantheon is still standing after 2,000 years.
https://www.cnn.com/style/article/roman-concrete-mystery-ingredient-scn/index.html
That stuff about the quicklime slurry seems to be a departure from what they\'ve always known about Roman concrete, and that is it was very dry. It is estimated Roman concrete was only 10-15 % water by weight, it was not pourable and had to be muscled into place by pounding. Modern formulation is 20-30 % water by mass and is significantly weaker upon cure than the dry mix, but, the convenience, if not the necessity, of being able to pour it into forms is more important.
Modern technology has found a better substitute for pozzuoli in the form of fly ash captured from coal burning.

\"modern\", the cement here factory have been using fly ash from the neighboring coal fired power plant since 1978 ..