Saturday, April 28, 2007

Re: Using steel chains as concrete reinforcement??

This reminded of a word-of-mouth storey I heard about engineers in
British Columbia retro-fitting older masonry buildings by drilling a
hole and dropping down aircraft cable which was anchored at the low end
and then tensioned at the top and then grouted.
Gary

Jordan Truesdell, PE wrote:
> I wondered the same thing at first. Nuts or undiscovered genius? But
> on reflection, this would be an innovative solution for retrofit
> reinforcing of a un(der)reinforced wall which was below an existing
> floor where there was no access to put a full length of rebar in from
> the top or sides, and an internal stiffener was impractical or would
> require expensive changes to fixes or loss of business use of the area.
> The placement would, indeed, be somewhat problematic, but with a high
> lift grout measured by patty size and a bit of vibration, you could
> probably expect a roughly vertical drop of a sufficiently heavy chain,
> especially if it were placed with a weighted end - say a bar with a
> stud or two - in 1-2 courses of grout for an initial set, then lifted
> taught for grouting.
>
> It would take a special application for this to be cost effective, but
> I can see how there might be a significant savings over invasive
> reinforcement techniques.
>
> Jordan
>
>
>
> Stan E Scholl wrote:
>> I don't understand why anyone would want to do this unless they had some
>> leftover chain since I am quite sure that rebars are much cheaper for
>> the
>> same capacity. Furthermore how can proper clearance be assured when the
>> chair will move all over when the grout pushes against it?
>>
>> Stan Scholl, P.E.
>> Laguna Beach, CA
>>
>
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new way of using chain

From: Ibrahim Mohammad <ibrahim@aa-engineers.com>
To: seaint@seaint.org
Subject: Using steel chains as concrete reinforcement??

This is a multi-part message in MIME format.
--------------060305010909000506060009
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit

Hi,
I'm working on a job in which the engineer is using a novel way to
reinforce CMU walls. He's using steel chains instead of rebar, inserted
from the top and then full grouted with 4000psi concrete. I guess he's
been asked to justify the process and so he's come to us to do an
evaluation. I was wondering if anyone had come across such a situation
before and could advice us about the viability of such a process.
Just from first glance, I feel that using chains as concrete
reinforcement would lead to local stress concentrations that could cause
the chain to break or yield locally. Perhaps it might be ok to use these
chains at a lower strength value than what they're rated for.
Any advice would be greatly appreciated.
Thanks
ibrahim

REPLY:

A failure of a chain is usually accompanied by local bending at junction

and the sides of a link coming together in process.

This should be largely suppressed when in concrete.

The chain should therefore be stronger.

Sincerely, Gregory from Oz

Re: Using steel chains as concrete reinforcement??

Unless somebody has some test data I would run from
this idea. It seems more questionable than the old
idea of using un stressed PT tendon in place of mild
steel.

If the chains did not have some initial stress they
would not be effective until all of the slack was
taken up. In addition it is not clear that the chain
would have the ductility that rebar has and which our
codes assume is there. I also would expect that the
chain would have a lower stiffness than a mild bar.

On the other hand there has been some positive
experience uning bamboo.

Mark Gilligan

******* ****** ****** ****** ******* ****** ****** ********

Jeff Giger/DAN/Minerals/METSO is out of the office.

I will be out of the office starting 04/27/2007 and will not return until
05/04/2007.

I will respond to your message when I return. For further needed assistance
call Barry Trumbauer at 271-7691 or Dave Ernest at 271-7665.

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Friday, April 27, 2007

Re: Mold growth

Thanks Richard. I'll share with y'all whatever I can find on those sites.

Ray Shreenan

----- Original Message -----

From: Richard L. Hess

To: seaint@seaint.org

Sent: Friday, April 27, 2007 3:28 PM

Subject: RE: Mold growth

Ray,

As you said, mold growth depends on many things in addition to the length of moisture exposure. A useful publication by the Foundation of the Wall and Ceiling Industry is called "Mold: Cause, Effect and Response". Their web site is www.awci.org, phone: (703) 534-8300. Another source is the American Industrial Hygiene Association at www.aiha.org.

Lawyers tend to look for the easy reason that they can get someone (an "expert") to say that they can measure. Where we engineers and architects come in is designing buildings that do not use materials that are conducive to mold, and designing details that allow drainage of water that comes in around flashing or condenses in non ventilated spaces.

Good luck. Keep us informed on what you find out.

Richard Hess S.E., A.E.

-----Original Message-----
From: Raymond Shreenan [mailto:rshreenan@adelphia.net]
Sent: Friday, April 27, 2007 1:37 PM
To: seaint@seaint.org
Subject: Mold growth

Hi sport fans:

There is fungus among us :>)

Does any one have a handle on the average time it takes for leaking water from a slow leak in a plumbing line to create large areas of black mildew or mold on drywall from wicking up from the source? This is not necessarily a structural problem but it can be later when dry rot sets in. This has become a critical issue with insurance companies who insure residential structures. The policies for home owners generally don't cover damage due to long term plumbing leaks and now they are insisting on written evidence that the damage was short term, a week or less or long term.

On occasion, I inspect structural damage claims for insurance companies. One of the concerns by the adjusters regarding damage due to plumbing leaks is the time period from initial leak to discovery. In the past when I have found large water stains on dry wall or wood combined with significant areas of mildew or mold, I have assumed that it was from long term water intrusion. Now the insurance adjusters want it pinned down time wise but I don't know that it can be. There are probably many factors that can affect the growth of fungus including temperature and ambient humidity. In a residential kitchen, these factors I think would likely be minimal.

This last damage claim of this type was due to a leaking small diameter water line to the refrigerator ice maker and the wall behind the appliance had a large blackened area with several other smaller black areas.

Thanks in advance for any info or references you may have.

Ray Shreenan SE

RE: Mold growth

Ray,

As you said, mold growth depends on many things in addition to the length of moisture exposure. A useful publication by the Foundation of the Wall and Ceiling Industry is called "Mold: Cause, Effect and Response". Their web site is www.awci.org, phone: (703) 534-8300. Another source is the American Industrial Hygiene Association at www.aiha.org.

Lawyers tend to look for the easy reason that they can get someone (an "expert") to say that they can measure. Where we engineers and architects come in is designing buildings that do not use materials that are conducive to mold, and designing details that allow drainage of water that comes in around flashing or condenses in non ventilated spaces.

Good luck. Keep us informed on what you find out.

Richard Hess S.E., A.E.

-----Original Message-----
From: Raymond Shreenan [mailto:rshreenan@adelphia.net]
Sent: Friday, April 27, 2007 1:37 PM
To: seaint@seaint.org
Subject: Mold growth

Hi sport fans:

There is fungus among us :>)

Does any one have a handle on the average time it takes for leaking water from a slow leak in a plumbing line to create large areas of black mildew or mold on drywall from wicking up from the source? This is not necessarily a structural problem but it can be later when dry rot sets in. This has become a critical issue with insurance companies who insure residential structures. The policies for home owners generally don't cover damage due to long term plumbing leaks and now they are insisting on written evidence that the damage was short term, a week or less or long term.

On occasion, I inspect structural damage claims for insurance companies. One of the concerns by the adjusters regarding damage due to plumbing leaks is the time period from initial leak to discovery. In the past when I have found large water stains on dry wall or wood combined with significant areas of mildew or mold, I have assumed that it was from long term water intrusion. Now the insurance adjusters want it pinned down time wise but I don't know that it can be. There are probably many factors that can affect the growth of fungus including temperature and ambient humidity. In a residential kitchen, these factors I think would likely be minimal.

This last damage claim of this type was due to a leaking small diameter water line to the refrigerator ice maker and the wall behind the appliance had a large blackened area with several other smaller black areas.

Thanks in advance for any info or references you may have.

Ray Shreenan SE

RE: Let the floodgates open (was: SHOOTINGS)

Return Receipt

Your RE: Let the floodgates open (was: SHOOTINGS)
document:

was Trib K Mittra/Beaumont/CBI
received
by:

at: 04/27/2007 04:56:42 PM

******* ****** ****** ****** ******* ****** ****** ********

Mold growth

Hi sport fans:

There is fungus among us :>)

Does any one have a handle on the average time it takes for leaking water from a slow leak in a plumbing line to create large areas of black mildew or mold on drywall from wicking up from the source? This is not necessarily a structural problem but it can be later when dry rot sets in. This has become a critical issue with insurance companies who insure residential structures. The policies for home owners generally don't cover damage due to long term plumbing leaks and now they are insisting on written evidence that the damage was short term, a week or less or long term.

On occasion, I inspect structural damage claims for insurance companies. One of the concerns by the adjusters regarding damage due to plumbing leaks is the time period from initial leak to discovery. In the past when I have found large water stains on dry wall or wood combined with significant areas of mildew or mold, I have assumed that it was from long term water intrusion. Now the insurance adjusters want it pinned down time wise but I don't know that it can be. There are probably many factors that can affect the growth of fungus including temperature and ambient humidity. In a residential kitchen, these factors I think would likely be minimal.

This last damage claim of this type was due to a leaking small diameter water line to the refrigerator ice maker and the wall behind the appliance had a large blackened area with several other smaller black areas.

Thanks in advance for any info or references you may have.

Ray Shreenan SE

RE: Let the floodgates open (was: SHOOTINGS)

Ah! But Jordan, with all respect to the one famous author of "time" who
passed away recently; there is still the Chronosynclasticinfindibulum!!!
Kurt Vonnogut for those who don't recall :>) Then there is Einsteins theory
that time can be folded over itself as was the theme of the recent film Déjà
vu. Personally, I prefer Vonnugut's ideas - because we can move back and
forth in time to witness any time from the day we were born to the day we
die (thus the idea of the Chronosynclasticinfindibulum).

Now that you think I'm nuts - the truth is that you can't stop someone from
committing a criminal act until they have committed it, but you can stop
someone from purchasing a legal weapon who is deemed mentally unstable or
capable of committing such acts. The shooter slipped through the system
because of flaws in the difference of how mental is differentiated from
medical health. This was discussed on most news networks today, btw. The
system can be tweaked and the results do not violate anyone's constitutional
rights but simply takes the mental stability of an individual into account
in greater detail than had he been arrested and required under law to be
committed where it would show up on his record prior to requesting a license
for a handgun.

Time to get back to tomorrow :>)

sinneD

Dennis S. Wish, PE
California Professional Engineer
Structural Engineering Consultant
C-41250 (Exp. 3/31/09)
dennis.wish@verizon.net
http://structuralist.spaces.live.com

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-----Original Message-----
From: Jordan Truesdell, PE [mailto:seaint1@truesdellengineering.com]
Sent: Tuesday, April 24, 2007 6:59 PM
To: seaint@seaint.org
Subject: Let the floodgates open (was: SHOOTINGS)

Oh, what the heck...everybody else is splashing about in the pool...

I'm curious, Bob, which form of "pre-crime" detection and incarceration
would you prefer. I like the option put forth in Minority Report, but
good psychics are hard to find, and even the best seem to be a bit
unreliable...one might even say "unstable." (naturally they wouldn't be
allowed CCW) It also has a difficult effect of adding to the
incarcerated population if you don't have an effective suspended
animation storage facility. Of course, there's Orwell's recommendation
that all the TVs simply be 2-way and on on the time (the latter already
true in the US - the former being rolled out in the UK even as I type).
The conversion methods seemed a bit harsh, though. Then, of course,
there's Huxley's take - though I would caution that you'd better make
sure the soma never runs out.

As for the 2nd amendment, If we're going with the theory that the
populace should be armed to ensure that the government never believes it
is beyond reproach by the citizenry, I think we ought to at least allow
personal purchases of everything up to tactical nukes...with a voluntary
background check, of course. When the government comes for me, I want to
have a fighting chance. ;-)

Jordan

P.S. - for those who don't remember, back when guns were legal DC was
always in the running - and often "won" - the title of Murder Capitol of
the US (I know, I lived there in the 80s and 90s). I'm not sure you can
show direct causality - there are always too many factors to be certain.
Of course, I'd like to think it was Marion Barry's fault ('mayor for
life'), too but - again - hard to pin down.

Robert Kazanjy wrote:
>
> But IMO it was a systemic failure of the campus community (school
> authorities, police & mental health professionals)
>
> How many of his teachers notified authorities of his odd behavior? I
> heard something like eight!
>
> IMO this incident wasn't a failure of gun control, there wasn't even
> a failure to identify the problem..........
> it was a failure to craft an appropriate response.
>
>
> We're just lucky he didn't choose to do something worse
>
> He was a deeply disturbed person & needed to be dealt with
> effectively BEFORE he did something bad.
>

******* ****** ****** ****** ******* ****** ****** ********

Re: Using steel chains as concrete reinforcement??

And "only" 40 years old!

Thanks, Bill.

Ralph

In a message dated 4/27/07 12:38:53 PM, bcainse@aol.com writes:

The U.S. Navy Civil Engineering Laboratory in Port Hueneme, CA developed a document on use of bamboo as concrete reinforcement. BAMBOO REINFORCED CONCRETE CONSTRUCTION
February 1966
U. S. NAVAL CIVIL ENGINEERING LABAORATORY
Port Hueneme, California
By
Francis E. Brink and Paul J. Rush

It can be found at: http://www.romanconcrete.com/docs/bamboo1966/BambooReinforcedConcreteFeb1966.htm

Please note the caveats listed.

Regards,
Bill Cain, S.E.
Berkeley CA

-----Original Message-----
From: Rhkratzse@aol.com
To: smithegr@bellsouth.net; seaint@seaint.org
Sent: Fri, 27 Apr 2007 7:51 AM
Subject: Re: Using steel chains as concrete reinforcement??

Sounds somewhat similar to Buckminster Fuller's idea of using bamboo to reinforce concrete in developing areas.

Ralph

In a message dated 4/27/07 7:41:18 AM, smithegr@bellsouth.net writes:

I had a contractor indicate they had just finished a rehab project in which the engineer used to chains to reinforce the cells and then grouted them full. I wouldn't go for it on our rehab project, but either they encountered the same engineer or this is become more common. I would think you would need some testing to verify bond capacity. I would also question how do you maintain tolerances with a flexible member? Do you have one guy pull on the top of the chain while you grout it?

bks

----- Original Message -----
From: Ibrahim Mohammad
To: seaint@seaint.org
Sent: Friday, April 27, 2007 9:03 AM
Subject: Using steel chains as concrete reinforcement??

Hi,
I'm working on a job in which the engineer is using a novel way to
reinforce CMU walls. He's using steel chains instead of rebar, inserted
from the top and then full grouted with 4000psi concrete. I guess he's
been asked to justify the process and so he's come to us to do an
evaluation. I was wondering if anyone had come across such a situation
before and could advice us about the viability of such a process.
Just from first glance, I feel that using chains as concrete
reinforcement would lead to local stress concentrations that could cause
the chain to break or yield locally. Perhaps it might be ok to use these
chains at a lower strength value than what they're rated for.
Any advice would be greatly appreciated.
Thanks
ibrahim

--
--------------------------
Ibrahim Z Mohammad
Assistant Engineer
A & A Engineering

5911 Renaissance Place, Suite B
Toledo OH 43623
Tel No.: 419-292-1983
Fax No.: 419-292-0955
--------------------------

**************************************
See what's free at http://www.aol.com.

Re: Using steel chains as concrete reinforcement??

The U.S. Navy Civil Engineering Laboratory in Port Hueneme, CA developed a document on use of bamboo as concrete reinforcement.

BAMBOO REINFORCED CONCRETE CONSTRUCTION

February 1966
U. S. NAVAL CIVIL ENGINEERING LABAORATORY
Port Hueneme, California
By
Francis E. Brink and Paul J. Rush

It can be found at:

http://www.romanconcrete.com/docs/bamboo1966/BambooReinforcedConcreteFeb1966.htm

Please note the caveats listed.

Regards,

Bill Cain, S.E.

Berkeley CA

-----Original Message-----
From: Rhkratzse@aol.com
To: smithegr@bellsouth.net; seaint@seaint.org
Sent: Fri, 27 Apr 2007 7:51 AM
Subject: Re: Using steel chains as concrete reinforcement??

Sounds somewhat similar to Buckminster Fuller's idea of using bamboo to reinforce concrete in developing areas.

Ralph

In a message dated 4/27/07 7:41:18 AM, smithegr@bellsouth.net writes:

I had a contractor indicate they had just finished a rehab project in which the engineer used to chains to reinforce the cells and then grouted them full. I wouldn't go for it on our rehab project, but either they encountered the same engineer or this is become more common. I would think you would need some testing to verify bond capacity. I would also question how do you maintain tolerances with a flexible member? Do you have one guy pull on the top of the chain while you grout it?

bks

----- Original Message -----
From: Ibrahim Mohammad
To: seaint@seaint.org
Sent: Friday, April 27, 2007 9:03 AM
Subject: Using steel chains as concrete reinforcement??

Hi,
I'm working on a job in which the engineer is using a novel way to
reinforce CMU walls. He's using steel chains instead of rebar, inserted
from the top and then full grouted with 4000psi concrete. I guess he's
been asked to justify the process and so he's come to us to do an
evaluation. I was wondering if anyone had come across such a situation
before and could advice us about the viability of such a process.
Just from first glance, I feel that using chains as concrete
reinforcement would lead to local stress concentrations that could cause
the chain to break or yield locally. Perhaps it might be ok to use these
chains at a lower strength value than what they're rated for.
Any advice would be greatly appreciated.
Thanks
ibrahim

--
--------------------------
Ibrahim Z Mohammad
Assistant Engineer
A & A Engineering

5911 Renaissance Place, Suite B
Toledo OH 43623
Tel No.: 419-292-1983
Fax No.: 419-292-0955
--------------------------

**************************************
See what's free at http://www.aol.com.

AOL now offers free email to everyone. Find out more about what's free from AOL at AOL.com.

RE: Using steel chains as concrete reinforcement??

As long as we're thinking outside the box, what about using the chain to PT
the wall, like Dur-O-Wall's masonry PT system? You'd have to come up with
some way to stress the chain and lock it in place. Once it's stressed, you
could grout the cells with reasonable confidence that the chain is centered,
or you could leave it ungrouted, like in Dur-O-Wall's system.

-- Joel

Joel C. Adair, P.E.
Project Manager
the structural alliance, Inc.

-----Original Message-----
From: Jordan Truesdell, PE [mailto:seaint1@truesdellengineering.com]
Sent: Friday, April 27, 2007 12:06 PM
To: seaint@seaint.org
Subject: Re: Using steel chains as concrete reinforcement??

I wondered the same thing at first. Nuts or undiscovered genius? But on
reflection, this would be an innovative solution for retrofit
reinforcing of a un(der)reinforced wall which was below an existing
floor where there was no access to put a full length of rebar in from
the top or sides, and an internal stiffener was impractical or would
require expensive changes to fixes or loss of business use of the area.

The placement would, indeed, be somewhat problematic, but with a high
lift grout measured by patty size and a bit of vibration, you could
probably expect a roughly vertical drop of a sufficiently heavy chain,
especially if it were placed with a weighted end - say a bar with a stud
or two - in 1-2 courses of grout for an initial set, then lifted taught
for grouting.

It would take a special application for this to be cost effective, but I
can see how there might be a significant savings over invasive
reinforcement techniques.

Jordan

Stan E Scholl wrote:
> I don't understand why anyone would want to do this unless they had some
> leftover chain since I am quite sure that rebars are much cheaper for the
> same capacity. Furthermore how can proper clearance be assured when the
> chair will move all over when the grout pushes against it?
>
> Stan Scholl, P.E.
> Laguna Beach, CA
>

******* ****** ****** ****** ******* ****** ****** ********

RE: Using steel chains as concrete reinforcement??

Ibrahim:

This appears to be applying to a new design, or is this a retrofit to an existing CMU wall?
Rebar is used for both compression and tension forces, while I am not comfortable assuming chain can do the same.
Also the alloy and yield value of a chain is not the same as ASTM A-615 or A-706 rebar.

Regards
Casey (Khashayar) Hemmatyar
Private email <k@hemmatyar.com>
California

-----Original Message-----
From: Ibrahim Mohammad [mailto:ibrahim@aa-engineers.com]
Sent: Friday, April 27, 2007 7:03 AM
To: seaint@seaint.org
Subject: Using steel chains as concrete reinforcement??

Hi,

I'm working on a job in which the engineer is using a novel way to

reinforce CMU walls. He's using steel chains instead of rebar, inserted

from the top and then full grouted with 4000psi concrete. I guess he's

been asked to justify the process and so he's come to us to do an

evaluation. I was wondering if anyone had come across such a situation

before and could advice us about the viability of such a process.

Just from first glance, I feel that using chains as concrete

reinforcement would lead to local stress concentrations that could cause

the chain to break or yield locally. Perhaps it might be ok to use these

chains at a lower strength value than what they're rated for.

Any advice would be greatly appreciated.

Thanks

ibrahim

--------------------------

Ibrahim Z Mohammad

Assistant Engineer

A & A Engineering

5911 Renaissance Place, Suite B

Toledo OH 43623

Tel No.: 419-292-1983

Fax No.: 419-292-0955

--------------------------

Re: Using steel chains as concrete reinforcement??

Sorry for the double post, but I realized I didn't give an example:

Residential URM basement wall undergoing backfill-related cracking.
First floor has a 2' cantilever over the basement level. Basement is
finished, front yard has mature landscaping and pavers to within 16" of
the sill plate. Add this twist - there's an abandoned-in-place oil tank
in the front yard for the previous oil-fired furnace.

Total cost of structural repairs using chain - $6000
Total cost to repair from the inside with steel or carbonfiber,
including repair replacement of finishes and cleanup - $10,000
Total cost to repair from the outside by excavating, cutting out block,
and using bars, plus tank mitigation and new lansdcaping - $15,000

I'm guessing at the chain part (based on rebar augmentation), but the
other numbers are from jobs we've been involved with. Chain looks
pretty attractive if it works, from the point of view of the homeowner.

Jordan

Josh Comfort wrote:
> I had the same thoughts Stan. The only reason I could come up with was if
> there was inadequate clearance over the top of the wall to drop a bar in.
> Nonetheless, I would make them knock out the face shells and place the bar
> from the side before I'd go the "chain" route.
>

******* ****** ****** ****** ******* ****** ****** ********

Re: Using steel chains as concrete reinforcement??

It would take a special application for this to be cost effective, but I
can see how there might be a significant savings over invasive
reinforcement techniques.

Jordan

******* ****** ****** ****** ******* ****** ****** ********

RE: Using steel chains as concrete reinforcement??

I had the same thoughts Stan. The only reason I could come up with was if
there was inadequate clearance over the top of the wall to drop a bar in.
Nonetheless, I would make them knock out the face shells and place the bar
from the side before I'd go the "chain" route.

-----Original Message-----
From: Stan E Scholl [mailto:sscholl2@juno.com]
Sent: Friday, April 27, 2007 9:52 AM
To: seaint@seaint.org
Subject: Re: Using steel chains as concrete reinforcement??

I don't understand why anyone would want to do this unless they had some
leftover chain since I am quite sure that rebars are much cheaper for the
same capacity. Furthermore how can proper clearance be assured when the
chair will move all over when the grout pushes against it?

Stan Scholl, P.E.
Laguna Beach, CA

******* ****** ****** ****** ******* ****** ****** ********

Re: Using steel chains as concrete reinforcement??

Stan Scholl, P.E.
Laguna Beach, CA

******* ****** ****** ****** ******* ****** ****** ********

Re: helical earth anchors

In a message dated 4/26/2007 4:04:57 PM Pacific Daylight Time, bart@nbse.com writes:

I have not found any of these systems to work very well in liquifiable soils or in frost type situations.

I agree, nor do they "qualify" for resisiting lateral loads (perpendiclar to the "piles") unless you put them on an angle (in both directions in the same plane) and using them in compression only.

Antonio S. Luisoni

Conculting S.E.

Granada Hills, CA

See what's free at AOL.com.

helical anchors

Hi Michael:

Helical anchors I have used are Dixie. http://www.calhelicalsolutions.com/helical_anchor_projects.htm

When installed, one of the parameters is that the contractor achieve a specified torque on the anchor. If this torque is not achieved, the anchor is installed deeper, or the contractor has the option of using a larger helix, or an extension with a greater number or helices.

The value of the torque is related through testing to the strength of the anchor, both compression and tension.

If the soil is relatively wet, the torque would be very low, and unacceptable.

For hospital projects we always specify a compression load test on an anchor or a sample anchor. This would provide additional local assurance of the performance.

This is one of the reasons I like helical anchors. If loose or wet soil in the particular location of the anchor is experienced, the anchor can be extended through the loose material.

The soils report is also critical since it will tell you if you have hard layers at the top of the soil which are not adequate to hold the designed load, and which you will want to penetrate.

Respectfully,

Bob Freeman, Structural Designer

Architect

Re: Using steel chains as concrete reinforcement??

Sounds somewhat similar to Buckminster Fuller's idea of using bamboo to reinforce concrete in developing areas.

Ralph

In a message dated 4/27/07 7:41:18 AM, smithegr@bellsouth.net writes:

I had a contractor indicate they had just finished a rehab project in which the engineer used to chains to reinforce the cells and then grouted them full. I wouldn't go for it on our rehab project, but either they encountered the same engineer or this is become more common. I would think you would need some testing to verify bond capacity. I would also question how do you maintain tolerances with a flexible member? Do you have one guy pull on the top of the chain while you grout it?

bks

----- Original Message -----
From: Ibrahim Mohammad
To: seaint@seaint.org
Sent: Friday, April 27, 2007 9:03 AM
Subject: Using steel chains as concrete reinforcement??

Hi,
I'm working on a job in which the engineer is using a novel way to
reinforce CMU walls. He's using steel chains instead of rebar, inserted
from the top and then full grouted with 4000psi concrete. I guess he's
been asked to justify the process and so he's come to us to do an
evaluation. I was wondering if anyone had come across such a situation
before and could advice us about the viability of such a process.
Just from first glance, I feel that using chains as concrete
reinforcement would lead to local stress concentrations that could cause
the chain to break or yield locally. Perhaps it might be ok to use these
chains at a lower strength value than what they're rated for.
Any advice would be greatly appreciated.
Thanks
ibrahim

--
--------------------------
Ibrahim Z Mohammad
Assistant Engineer
A & A Engineering

5911 Renaissance Place, Suite B
Toledo OH 43623
Tel No.: 419-292-1983
Fax No.: 419-292-0955
--------------------------

**************************************
See what's free at http://www.aol.com.

Re: Using steel chains as concrete reinforcement??

I had a contractor indicate they had just finished a rehab project in which the engineer used to chains to reinforce the cells and then grouted them full. I wouldn't go for it on our rehab project, but either they encountered the same engineer or this is become more common. I would think you would need some testing to verify bond capacity. I would also question how do you maintain tolerances with a flexible member? Do you have one guy pull on the top of the chain while you grout it?

bks

----- Original Message -----

From: Ibrahim Mohammad

To: seaint@seaint.org

Sent: Friday, April 27, 2007 9:03 AM

Subject: Using steel chains as concrete reinforcement??

Hi,
I'm working on a job in which the engineer is using a novel way to
reinforce CMU walls. He's using steel chains instead of rebar, inserted
from the top and then full grouted with 4000psi concrete. I guess he's
been asked to justify the process and so he's come to us to do an
evaluation. I was wondering if anyone had come across such a situation
before and could advice us about the viability of such a process.
Just from first glance, I feel that using chains as concrete
reinforcement would lead to local stress concentrations that could cause
the chain to break or yield locally. Perhaps it might be ok to use these
chains at a lower strength value than what they're rated for.
Any advice would be greatly appreciated.
Thanks
ibrahim

--
--------------------------
Ibrahim Z Mohammad
Assistant Engineer
A & A Engineering

5911 Renaissance Place, Suite B
Toledo OH 43623
Tel No.: 419-292-1983
Fax No.: 419-292-0955
--------------------------

No virus found in this incoming message.
Checked by AVG Free Edition.
Version: 7.5.463 / Virus Database: 269.6.1/776 - Release Date: 4/25/2007 12:19 PM

Using steel chains as concrete reinforcement??

Hi,
I'm working on a job in which the engineer is using a novel way to
reinforce CMU walls. He's using steel chains instead of rebar, inserted
from the top and then full grouted with 4000psi concrete. I guess he's
been asked to justify the process and so he's come to us to do an
evaluation. I was wondering if anyone had come across such a situation
before and could advice us about the viability of such a process.
Just from first glance, I feel that using chains as concrete
reinforcement would lead to local stress concentrations that could cause
the chain to break or yield locally. Perhaps it might be ok to use these
chains at a lower strength value than what they're rated for.
Any advice would be greatly appreciated.
Thanks
ibrahim

--
--------------------------
Ibrahim Z Mohammad
Assistant Engineer
A & A Engineering

5911 Renaissance Place, Suite B
Toledo OH 43623
Tel No.: 419-292-1983
Fax No.: 419-292-0955
--------------------------

Helical anchors in saturated soils

Anyone know or know where to look for information regarding helical anchors
in saturated soils? The browsing I've done on the internet only showed
capacity of the anchors in a 'dry' condition I'm assuming.

I'm curious how these anchors fare in storm conditions where the ground may
be saturated (heavy rain or flood).

More specifically, I've noticed the helical anchors are being specified for
use in hold down applications where tornado or hurricane activity may be
prevalent. So how do these anchors hold 'up' (really down without the pun)
when the soil has been saturated?

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Thursday, April 26, 2007

Re: helical earth anchors

There are certain schools of thought which do not have a high regard for helical anchors.

Regardless, there some things can be done.

Predrill an augered hole, 12" -18" in dia., sleeve if necessary, and fill with concrete. Use enough concrete to counteract uplift loads through DL or combined with skin friction. Some areas of the country are simply averse to augered holes, so you need to clear this path up front.

Weld helical flanges onto large diameter pipe, and install the same way. Large pipes give you some bending capacity. These can be installed with mostly the same equipment, especially if you have a sharp contractor.

Use a threaded rod to attach to the hold down, and run the threaded rod down into the augered and grouted hole, deep enough to get the capacity you need. I am not aware of any requirement for preloading testing for holdown anchors anyway, so you can use an augered and grouted hole, in a design manner similar to concrete footings.

Also, an augered hole filled with concrete provides some lateral resistance and bending capacity.

I have not found any of these systems to work very well in liquifiable soils or in frost type situations.

----- Original Message -----
From: "Christopher Banbury"
To: seaint@seaint.org
Subject: helical earth anchors
Date: Thu, 26 Apr 2007 16:38:07 -0400

Speaking of helical earth anchors and wind loads reminds me…

I am researching a method to connect helical earth anchors directly to Simpson frame hold-downs like the PHD series.

Most of the helical systems intended for anchoring temporary buildings have a coil strap or cable that is intended to wrap over or through the structure.

The top end of the helical anchor would need to have a threaded end to receive a threaded rod coupler. Most of the helical anchors I have seen rated in the 2500# range have a proprietary end.

I think there may also be an issue with pre-loading the earth anchor.

Thanks.

Christopher Banbury, PE

President

Ark Engineering, Inc.

PO Box 10129, Brooksville, FL 34603

22 N. Broad ST, Brooksville, FL 34601

Phone: (352) 754-2424

FAX: (352) 754-2412

www.arkengineering.net

<< image001.gif >>

Bart Needham, SE Principal, nbse associates, inc. Office 206-780-6822 Office 805-452-8152 Fax    206-780-6683 Fax    208-693-3667 Mobile 206-300-2346  Office locations: 629 State Street #230 Santa Barbara, CA  93101  205 Fairview Lane Suite 100 Paso Robles, CA  93446  355 Ericksen Ave. NE Suite 422 Bainbridge Island, WA  98110  Mail and Deliveries: 321 High School Rd. NE Suite D-3 PMB 216 Bainbridge Island, WA  98110

RE: Manufactured housing foundations

It is odd, but not surprising that a HUD funded document in 1996 is not
consistant with a HUD document in 1999. The 1999 document gives tables and
examples of dry stack CMU, but provides for angled tie downs and height
limits for the dry stack CMU. The 1996 document does not have that much on
the tie downs.

BTW there is also FEMA 85 which gives guidance for foundations for
manufactured homes in flood plains.

Regards,
Harold Sprague

>From: "Gary Loomis" <gloomis@MasterEngineersinc.com>
>Reply-To: <seaint@seaint.org>
>To: <seaint@seaint.org>
>Subject: RE: Manufactured housing foundations
>Date: Thu, 26 Apr 2007 16:37:19 -0400
>
>This is not consistent with Section 503-4, Masonry Piers and Walls of
>the "Permanent Foundations Guide for Manufactured Housing" prepared by
>US Dept. of Housing and Urban Development, dated September 1996. It
>states "All masonry piers and walls shall have mortared beds and head
>joints".
>
>www.huduser.org/Publications/pdf/foundation_guide_complete.pdf
>
>Our experience when HUD financing was involved, they would not accept
>dry stacked block even on homes installed before September 1996.
>
>We went to HUD with a request to use a surface bonding agent and they
>accepted this in lieu of the mortared joints. A letter stamped by a PE
>with backup calculations for dry stacked piers rejected.
>
>Suggest you check with the finance company to determine the
>requirements.
>
>Gary W. Loomis, P.E., Senior Structural Engineering
>Master Engineers and Designers, Inc.
>-----Original Message-----
>From: Harold Sprague [mailto:spraguehope@hotmail.com]
>Sent: Thursday, April 26, 2007 4:16 PM
>To: seaint@seaint.org
>Subject: Re: Manufactured housing foundations
>
>Jordan,
>
>According to HUD, dry stack CMU is allowed.
>Reference: http://www.pathnet.org/sp.asp?id=1003
>for the Manufactured Homes Installation Training Manual.
>
>It is a pretty good document representing practices and engineered
>solutions. HUD sponsored this and participated in the development. The
>
>Manufactured Homes Insititute also participated.
>
>Regards,
>Harold Sprague
>
>
> >----- Original Message ----- From: "Jordan Truesdell, PE"
> ><seaint1@truesdellengineering.com>
> >To: <seaint@seaint.org>
> >Sent: Wednesday, April 25, 2007 10:42 AM
> >Subject: Manufactured housing foundations
> >
> >
> >>Is anyone out there familiar enough with the PFGMH to know if there
>are
> >>any interpretations or modifications which allow the use of unmortared
>
> >>(dry stacked) CMU piers? Also, is there an interpretation which allows
>the
> >>exterior of the piers to be covered in a cementitious compound in lieu
>of
> >>mortared bed joints?
> >>
> >>--
> >>Jordan
>
>_________________________________________________________________
>The average US Credit Score is 675. The cost to see yours: $0 by
>Experian.
>http://www.freecreditreport.com/pm/default.aspx?sc=660600&bcd=EMAILFOOTE
>RAVERAGE
>
>
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Re: Manufactured housing foundations

This is exactly the discussion I was hoping to spark. I would say that most mfr homes in this area are built on dry-stacked block, and was curious how those offering HUD-financing reviews were handling it. Since there is no mention of even the bonding agent in the old guide, that puts quite a crimp in the resale market if everyone is actually enforcing the guidelines.

It's a shame that there is no official publication from HUD on the surface bonding cement.

Jordan

Gary Loomis wrote:

This is not consistent with Section 503-4, Masonry Piers and Walls of the "Permanent Foundations Guide for Manufactured Housing" prepared by US Dept. of Housing and Urban Development, dated September 1996.  It states "All masonry piers and walls shall have mortared beds and head joints".  www.huduser.org/Publications/pdf/foundation_guide_complete.pdf  Our experience when HUD financing was involved, they would not accept dry stacked block even on homes installed before September 1996.   We went to HUD with a request to use a surface bonding agent and they accepted this in lieu of the mortared joints.  A letter stamped by a PE with backup calculations for dry stacked piers rejected.  Suggest you check with the finance company to determine the requirements.  Gary W. Loomis, P.E., Senior Structural Engineering Master Engineers and Designers, Inc. -----Original Message----- From: Harold Sprague [mailto:spraguehope@hotmail.com]  Sent: Thursday, April 26, 2007 4:16 PM To: seaint@seaint.org Subject: Re: Manufactured housing foundations  Jordan,  According to HUD, dry stack CMU is allowed. Reference: http://www.pathnet.org/sp.asp?id=1003 for the Manufactured Homes Installation Training Manual.  It is a pretty good document representing practices and engineered  solutions.  HUD sponsored this and participated in the development.  The  Manufactured Homes Insititute also participated.  Regards, Harold Sprague

----- Original Message ----- From: "Jordan Truesdell, PE"  <seaint1@truesdellengineering.com> To: <seaint@seaint.org> Sent: Wednesday, April 25, 2007 10:42 AM Subject: Manufactured housing foundations

Is anyone out there familiar enough with the PFGMH to know if there

are

any interpretations or modifications which allow the use of unmortared

(dry stacked) CMU piers? Also, is there an interpretation which allows

the

exterior of the piers to be covered in a cementitious compound in lieu

of

mortared bed joints?  -- Jordan

 _________________________________________________________________ The average US Credit Score is 675. The cost to see yours: $0 by Experian.  http://www.freecreditreport.com/pm/default.aspx?sc=660600&bcd=EMAILFOOTE RAVERAGE   ******* ****** ******* ******** ******* ******* ******* *** *   Read list FAQ at: http://www.seaint.org/list_FAQ.asp *  *   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@seaint.org. Remember, any email you  *   send to the list is public domain and may be re-posted  *   without your permission. Make sure you visit our web  *   site at: http://www.seaint.org  ******* ****** ****** ****** ******* ****** ****** ********     ******* ****** ******* ******** ******* ******* ******* *** *   Read list FAQ at: http://www.seaint.org/list_FAQ.asp *  *   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@seaint.org. Remember, any email you  *   send to the list is public domain and may be re-posted  *   without your permission. Make sure you visit our web  *   site at: http://www.seaint.org  ******* ****** ****** ****** ******* ****** ****** ********

helical earth anchors

Speaking of helical earth anchors and wind loads reminds me…

I am researching a method to connect helical earth anchors directly to Simpson frame hold-downs like the PHD series.

Most of the helical systems intended for anchoring temporary buildings have a coil strap or cable that is intended to wrap over or through the structure.

The top end of the helical anchor would need to have a threaded end to receive a threaded rod coupler. Most of the helical anchors I have seen rated in the 2500# range have a proprietary end.

I think there may also be an issue with pre-loading the earth anchor.

Thanks.

Christopher Banbury, PE

President

Ark Engineering, Inc.

PO Box 10129, Brooksville, FL 34603

22 N. Broad ST, Brooksville, FL 34601

Phone: (352) 754-2424

FAX: (352) 754-2412

www.arkengineering.net

RE: Manufactured housing foundations

This is not consistent with Section 503-4, Masonry Piers and Walls of
the "Permanent Foundations Guide for Manufactured Housing" prepared by
US Dept. of Housing and Urban Development, dated September 1996. It
states "All masonry piers and walls shall have mortared beds and head
joints".

www.huduser.org/Publications/pdf/foundation_guide_complete.pdf

Our experience when HUD financing was involved, they would not accept
dry stacked block even on homes installed before September 1996.

We went to HUD with a request to use a surface bonding agent and they
accepted this in lieu of the mortared joints. A letter stamped by a PE
with backup calculations for dry stacked piers rejected.

Suggest you check with the finance company to determine the
requirements.

Gary W. Loomis, P.E., Senior Structural Engineering
Master Engineers and Designers, Inc.
-----Original Message-----
From: Harold Sprague [mailto:spraguehope@hotmail.com]
Sent: Thursday, April 26, 2007 4:16 PM
To: seaint@seaint.org
Subject: Re: Manufactured housing foundations

Jordan,

According to HUD, dry stack CMU is allowed.
Reference: http://www.pathnet.org/sp.asp?id=1003
for the Manufactured Homes Installation Training Manual.

It is a pretty good document representing practices and engineered
solutions. HUD sponsored this and participated in the development. The

Manufactured Homes Insititute also participated.

Regards,
Harold Sprague

>----- Original Message ----- From: "Jordan Truesdell, PE"
><seaint1@truesdellengineering.com>
>To: <seaint@seaint.org>
>Sent: Wednesday, April 25, 2007 10:42 AM
>Subject: Manufactured housing foundations
>
>
>>Is anyone out there familiar enough with the PFGMH to know if there
are
>>any interpretations or modifications which allow the use of unmortared

>>(dry stacked) CMU piers? Also, is there an interpretation which allows
the
>>exterior of the piers to be covered in a cementitious compound in lieu
of
>>mortared bed joints?
>>
>>--
>>Jordan

_________________________________________________________________
The average US Credit Score is 675. The cost to see yours: $0 by
Experian.

http://www.freecreditreport.com/pm/default.aspx?sc=660600&bcd=EMAILFOOTE
RAVERAGE

******* ****** ****** ****** ******* ****** ****** ********

RE: Manufactured housing foundations

I don't know about dry stack but here is a website that has some good
info on soil anchors and anchoring mobile homes for lateral loads.

Christopher Banbury, PE
President
Ark Engineering, Inc.
PO Box 10129, Brooksville, FL 34603
22 N. Broad ST, Brooksville, FL 34601
Phone: (352) 754-2424
FAX: (352) 754-2412
www.arkengineering.net

-----Original Message-----
From: Harold Sprague [mailto:spraguehope@hotmail.com]
Sent: Thursday, April 26, 2007 4:16 PM
To: seaint@seaint.org
Subject: Re: Manufactured housing foundations

Jordan,

According to HUD, dry stack CMU is allowed.
Reference: http://www.pathnet.org/sp.asp?id=1003
for the Manufactured Homes Installation Training Manual.

It is a pretty good document representing practices and engineered
solutions. HUD sponsored this and participated in the development. The

Manufactured Homes Insititute also participated.

Regards,
Harold Sprague

>>(dry stacked) CMU piers? Also, is there an interpretation which allows
the
>>exterior of the piers to be covered in a cementitious compound in lieu
of
>>mortared bed joints?
>>
>>--
>>Jordan

_________________________________________________________________
The average US Credit Score is 675. The cost to see yours: $0 by
Experian.

http://www.freecreditreport.com/pm/default.aspx?sc=660600&bcd=EMAILFOOTE
RAVERAGE

******* ****** ****** ****** ******* ****** ****** ********