[FoRK] KK: the art of endless upgrades
eugen at leitl.org
Tue May 17 23:39:30 PDT 2011
On Tue, May 17, 2011 at 04:58:11PM -0400, Gary Stock wrote:
> On 5/17/11 10:04 AM, Eugen Leitl wrote:
>> I can see very permanent
>> things decay in my own lifetime. Surprising, asphalt doesn't last forever,
>> nor do iron and even stone.
> I recall a class in Segovia, touching on design features of the
> aqueducts built there ~2,000 years ago. The professor noted that they
> may remain standing (and essentially functional) that long again --
> perhaps longer. He then commented on the pomposity of our use of steel
> rebar to "improve" concrete construction. In half that time,
> archaeologists will be either confused or amused by the little round red
> holes -- hollow tubes where those steel bars once were -- presuming any
> of the concrete remains intact.
Actually the rusting iron expands, and breaks up the concrete
matrix from within. The Roman concrete was not reinforced, and
Arguably today we could use mineral fiber reinforced concrete
or geopolymer, and achieve much better durability.
Eugen* Leitl <a href="http://leitl.org">leitl</a> http://leitl.org
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