KCEngineer
Structural
Trying to decide when I can and can't deviate from minimum steel requirements???
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Minimum Steel in Concrete 1
- Thread starter KCEngineer
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civilperson
Structural
Steel below minimums use Chapter 22 of ACI-318.
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1
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msquared48
Structural
I think you will find most of the prescriptive, or jurisdictional pre-approved foundations do not have minimum steel. Hate to say it, but it reminds me of the typical concrete and CMU reinforcing I have seen in Mexico - very little.
Mike McCann
McCann Engineering
Mike McCann
McCann Engineering
- Thread starter
- #5
DarthSoilsGuy
Geotechnical
MM^2-48
when i worked in honduras,
i typically saw a lot of 8"x8" square concrete column had 3-#3 verts tied by WWF type wires at 12" o.c. in a triangle pattern, and sometimes 4#3s verts.
Seriously, you saw CMU reinforcing?
in most of honduras, the snow loads are gone and wind loads rip the roof off anyway.
when i worked in honduras,
i typically saw a lot of 8"x8" square concrete column had 3-#3 verts tied by WWF type wires at 12" o.c. in a triangle pattern, and sometimes 4#3s verts.
Seriously, you saw CMU reinforcing?
in most of honduras, the snow loads are gone and wind loads rip the roof off anyway.
concretemasonry
Structural
msquared and DarthSoilsGuy -
A little off the minimum reinforcement subject, but not all southern countries have poor CMU construction. They have some very well designed and constucted masonry structures. Sometimes, the combination of concrete columns and masonry infill defies the traditional American approach, once the usual simplifying structural behavior assumptions are made. This gets complicated with the concurrent construction process of the columns and infill in the same walls. - The columns are green and uncured and the masonry units are cured, so the load transfer as the structure ages gets pretty dicey.
Without a doubt, some of the best masonry structures I have seen are the 15-20 story loadbearing masonry structures in Brazil. The structural engineering/detailing and construction interaction is far superior to most critcal masonry structures in the U.S. This is probably because of the historic use and understanding of masonry that has been enhanced by some of the U.S. masonry developments and codes starting in the 1960's.
Dick
A little off the minimum reinforcement subject, but not all southern countries have poor CMU construction. They have some very well designed and constucted masonry structures. Sometimes, the combination of concrete columns and masonry infill defies the traditional American approach, once the usual simplifying structural behavior assumptions are made. This gets complicated with the concurrent construction process of the columns and infill in the same walls. - The columns are green and uncured and the masonry units are cured, so the load transfer as the structure ages gets pretty dicey.
Without a doubt, some of the best masonry structures I have seen are the 15-20 story loadbearing masonry structures in Brazil. The structural engineering/detailing and construction interaction is far superior to most critcal masonry structures in the U.S. This is probably because of the historic use and understanding of masonry that has been enhanced by some of the U.S. masonry developments and codes starting in the 1960's.
Dick
msquared48
Structural
AarthSoilsGuy:
Yep, but for a prescriptive CMU wall/precast floor system in the Akumal area about an hour south of Cancun. This was about 10 years ago, and it was for a three story condo. Nice units, but I was not impressed with the structure. Makes me wonder how the buildings faired with the two hurricanes that passed through the area laast year - one would have been a direct hit as it came ashore at Telum, just to the south of the building I observed.
They did use #3 verticals in the CMU, at what I remember was a four to six foot spacing vertically, plus 4 vertical bars and tie bars in the columns. I believe they were usingsomething similar to K-web for the horizontal reinforcing, but cannot recall the spacing.
As I mentioned, I was not impressed, and I was staying in one of the units. Now I know why they evacuate the buildings when a hurricane comes close. I would leave to knowing what I know.
Mike McCann
McCann Engineering
Yep, but for a prescriptive CMU wall/precast floor system in the Akumal area about an hour south of Cancun. This was about 10 years ago, and it was for a three story condo. Nice units, but I was not impressed with the structure. Makes me wonder how the buildings faired with the two hurricanes that passed through the area laast year - one would have been a direct hit as it came ashore at Telum, just to the south of the building I observed.
They did use #3 verticals in the CMU, at what I remember was a four to six foot spacing vertically, plus 4 vertical bars and tie bars in the columns. I believe they were usingsomething similar to K-web for the horizontal reinforcing, but cannot recall the spacing.
As I mentioned, I was not impressed, and I was staying in one of the units. Now I know why they evacuate the buildings when a hurricane comes close. I would leave to knowing what I know.
Mike McCann
McCann Engineering
DarthSoilsGuy
Geotechnical
wait a second, aren't they the same masons, ![[thumbsup]](/data/assets/smilies/thumbsup.gif "[thumbsup] [thumbsup]")
brazil... c'mon, pick a country near honduras or mexico...
that's cheating.
ok, i should say that major construction projects are designed and built to up to international snuff (banks, malls, chain hotels,.... i'm not saying schools or prisons) in honduras. 1-2 story residential construction is what i was talking about.
brazil... c'mon, pick a country near honduras or mexico...
that's cheating.
ok, i should say that major construction projects are designed and built to up to international snuff (banks, malls, chain hotels,.... i'm not saying schools or prisons) in honduras. 1-2 story residential construction is what i was talking about.
msquared48
Structural
What you saw in Brazil was probably in either Brazilia or Sao Paulo (please pardon spelling), some major juridiction. I have seen the same quality of construction in Mexico City that you describe, and once know a structural engineer in Mexico City who designed flat slab high rise buildings there.
However, I was looking primarily at the outskirts of Mexico. As you drive around, there are scores of unfinished masonry buildings, rusting reinforcing still projecting vertically, where the owner ran out of money, for whatever reason, and I have heard many. This left me with a general impression, particularly when I had the opportunity to witness the construction firsthand myself, knowing what I have seen in the states.
Really made me wonder what the level of jurisdictional supervision was, if any - even if they had to get a permit. I understand that the "engineering" was done outside of the country. Did not observe any drawings or calculations, but had no authority to ask for such either.
Mike McCann
McCann Engineering
However, I was looking primarily at the outskirts of Mexico. As you drive around, there are scores of unfinished masonry buildings, rusting reinforcing still projecting vertically, where the owner ran out of money, for whatever reason, and I have heard many. This left me with a general impression, particularly when I had the opportunity to witness the construction firsthand myself, knowing what I have seen in the states.
Really made me wonder what the level of jurisdictional supervision was, if any - even if they had to get a permit. I understand that the "engineering" was done outside of the country. Did not observe any drawings or calculations, but had no authority to ask for such either.
Mike McCann
McCann Engineering
"scores of unfinished masonry buildings, rusting reinforcing still projecting vertically, where the owner ran out of money,"
In several countries of Central and South America (I do not know if Mexico is one of them), there is a tax to be paid on finished buildings. Hence, the buildings are left 'unfinished', that is, as if more floors were going to be added (and therefore rebar sticking out) and the brick walls not coated. That wasy the owners do not have to pay the tax but they still move in and live in them.
I am not saying it makes much sense, but that is what I have been told.
In several countries of Central and South America (I do not know if Mexico is one of them), there is a tax to be paid on finished buildings. Hence, the buildings are left 'unfinished', that is, as if more floors were going to be added (and therefore rebar sticking out) and the brick walls not coated. That wasy the owners do not have to pay the tax but they still move in and live in them.
I am not saying it makes much sense, but that is what I have been told.
LittleWheels
Structural
Definitely Greece, it looked like the whole country was a building site...
msquared48
Structural
As far as I could tell, these buildings were unoccupied for the most part.
The story that I was told is not the same as what you referred to. Had to do with drug dealers and the laundering of their money, and I forget the exact scenario. Could have been local urban legends. Who knows... All I know is that it looks like piss poor prior planning, and poor construction, at the very least.
Mike McCann
McCann Engineering
The story that I was told is not the same as what you referred to. Had to do with drug dealers and the laundering of their money, and I forget the exact scenario. Could have been local urban legends. Who knows... All I know is that it looks like piss poor prior planning, and poor construction, at the very least.
Mike McCann
McCann Engineering
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