YotaTech Forums  

Go Back   YotaTech Forums > Off Topic, Wiki Discussions, Fraudulent Vehicle Listings, & Stolen Rigs > Off Topic Talk
Sign in using an external account
Register Forgot Password?
Search


Off Topic Talk If it's non Toyota & tech related, put it here

Welcome to Yotatech!
Welcome to Yotatech,

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!


Reply
 
LinkBack Thread Tools Search this Thread
Old 05-09-2005, 03:20 PM   #1
Contributing Member
Personal Sales Rating: (0)
 
Tacoma Dude's Avatar
 
Join Date: Mar 2003
Location: Orange County, CA
Posts: 8,345
Send a message via AIM to Tacoma Dude
When does concrete dry?

I was watching an episode of Monster House the other day (LA Sheriff's Office - Compton dept.) when they were going at a hunk of concrete that was 40 years old. Steve Watson steps in and says that concrete continues to bake and bake over the years and gets harder and harder.

I was wondering - is this true? When does it stop hardening? It's got to stop sometime, right?
This ad is not displayed to registered members.
Register your free account today and become a member on Yotatech!
__________________
Peter!
2002 Tacoma
1986 4Runner
Tacoma Dude is offline   Reply With Quote
Old 05-09-2005, 03:22 PM   #2
Banned
Vendor Sales Rating: (0)
 
jimbo74's Avatar
 
Join Date: Jan 2004
Location: Nor*Cal
Posts: 6,590
Send a message via AIM to jimbo74
it takes a while to completely cure, but it should be dry well before 40 years time..... most of the time in dry conditions its dry to walk on in 2 days
jimbo74 is offline   Reply With Quote
Old 05-09-2005, 03:25 PM   #3
Contributing Member
Personal Sales Rating: (0)
Threadstarter [OP]
 
Tacoma Dude's Avatar
 
Join Date: Mar 2003
Location: Orange County, CA
Posts: 8,345
Send a message via AIM to Tacoma Dude
But it supposedly continues to set and get harder? That's what seems to be the case on several of these shows...?
__________________
Peter!
2002 Tacoma
1986 4Runner
Tacoma Dude is offline   Reply With Quote
Old 05-09-2005, 03:38 PM   #4
Banned
Vendor Sales Rating: (0)
 
jimbo74's Avatar
 
Join Date: Jan 2004
Location: Nor*Cal
Posts: 6,590
Send a message via AIM to jimbo74
since you dont like my answer, go find your own then
jimbo74 is offline   Reply With Quote
Old 05-09-2005, 03:40 PM   #5
Contributing Member
Personal Sales Rating: (0)
Threadstarter [OP]
 
Tacoma Dude's Avatar
 
Join Date: Mar 2003
Location: Orange County, CA
Posts: 8,345
Send a message via AIM to Tacoma Dude
You.. you...MEANIE!

Actually, what I meant was that I acknowledge that the concrete is dry within a few days, but does it really continue to harden? Is concrete that is 20 years old really tougher than concrete that is 1 year old?
Why is that?
__________________
Peter!
2002 Tacoma
1986 4Runner
Tacoma Dude is offline   Reply With Quote
Old 05-09-2005, 03:42 PM   #6
Contributing Member
Personal Sales Rating: (0)
 
bike4miles's Avatar
 
Join Date: May 2004
Location: Tucson, AZ
Posts: 3,401
Send a message via Yahoo to bike4miles
There is concreat inside the Hover Dam that is still drying according to my Engineering 211 (statics) instructor. The thicker it is, the longer it takes. The Hover Dam is the tickest chunk of concreat on the planett and will likely take hundreds of years to cure compleetly.
__________________
--Miles
Sold
'91 4runner, 22re, 5 spd manual, 180,000 miles,
cone filter, Downey 1.5"HD coils, SkyJacker Nitrogens, Magnaflow Exhaust, Stull grill, Clears all around. Check out my sound proofing project and other mods:
My 4runner page

My 2006 Camry page

I'm a Myspace Addict!
bike4miles is offline   Reply With Quote
Old 05-09-2005, 03:45 PM   #7
Contributing Member
Personal Sales Rating: (0)
 
Bassinfool's Avatar
 
Join Date: Jan 2005
Location: Roseville, CA
Posts: 887
HiTekkRedNekk Dimples McCree
Concrete does continue to harden over time. In the hoover dam, the inner concrete is still not cured It will take a few decades more before it cures. Concrete cures in a matter of 1 or 2 days (thin layers, 4"-6"), but you can put accellorators in it to quicken that process. It's really a fascinating product. The hardening process of concrete is actually an implosion of the materials that are mixed together which causes it to harden.
__________________

'01 Tacoma Xtra Cab, SR5, White
4WD
2.7l
Manual
146k Miles
Donahoe Racing Suspension Lift
33/12.50/15 BFG AT/KO's on Eagle alloys
K&N FIPK
Cat-Back exhaust
Line-X
Oh and I replaced all those broken foam tabbie things in the cupholders...
Bassinfool is offline   Reply With Quote
Old 05-09-2005, 04:11 PM   #8
Contributing Member
Personal Sales Rating: (0)
 
WATRD's Avatar
 
Join Date: Oct 2002
Location: Duvall, WA
Posts: 5,089
Despite what was mentioned earlier in the thread, concrete curing has nothing to do with it "drying" or how dry the conditions are. It's an exothermic chemical process, not dependant upon evaporation. That's why with the right mix, it can set while under water. Water does escape from the mix and the humidity can be used to partially throttle the speed of the cure, but it's not what actually does the hardening.

Read more here;

http://matse1.mse.uiuc.edu/~tw/concrete/ware.html
http://www.olemiss.edu/courses/engr3...roduction.html
http://www.etown.edu/Public.aspx?topic=Press%20releases-Nov.%202004-Hager's%20research
http://www.cement.org/basics/concretebasics_faqs.asp
http://www.cement.ca/cement.nsf/0/20...D?OpenDocument
__________________
-Rob
Slightly Modified 2001 Tacoma - WATRD.COM
WATTORA is now NWToys!
Tread Lightly! certified Tread Trainer

Search 100+ Toyota tech sites, including this one: All Toyota Search Engine
WATRD is offline   Reply With Quote
Old 05-09-2005, 04:11 PM   #9
Contributing Member
Personal Sales Rating: (0)
 
EWAYota's Avatar
 
Join Date: Dec 2003
Location: Richland, Washington
Posts: 4,586
Send a message via AIM to EWAYota Send a message via MSN to EWAYota
sidewalks aren't completely dry as well......a normal sidewalk, if you were to cut it up and look at it, the very middle will still be soft. it takes a sidewalk 100 years to completely cure. lol, just a tidbit i learned this winter working in the concrete business building bridges! and i thought i would never get to use that fact!
__________________
DJ
1994 Pickup, 22re, Engnbldr 261 cam, 5 speed. Tires that go around and around...
Preping for SAS, marlin hysteer, dual elockers, dual case (stock gears) with marlin adapter and Sky crossmember, TG Sliders, 37 mtr's on black 17x8 soft 8's......

1990 4runner SR5, 22re, auto....baby mobile
EWAYota is offline   Reply With Quote
Old 05-09-2005, 04:19 PM   #10
Contributing Member
Personal Sales Rating: (0)
 
WATRD's Avatar
 
Join Date: Oct 2002
Location: Duvall, WA
Posts: 5,089
And regarding how long concrete can take to set, that depends on the mix and the thickness...

Quote:
RE: Hoover Damn; Bureau of Reclamation engineers had calculated that if all 6.6 million tons of concrete were poured in one continuous operation, it would take 125 years for the dam to harden. In addition, the heat generated by the setting process would cause the concrete to crack and weaken. They developed an innovative approach: The concrete for the dam would be poured in individual blocks no more than five feet deep. Those blocks would be threaded with 650 miles of one-inch pipe carrying refrigerated water to cool the concrete and prevent cracking.
And some fun facts

http://www.chooseconcrete.com/choose...)?ID=fastFacts
__________________
-Rob
Slightly Modified 2001 Tacoma - WATRD.COM
WATTORA is now NWToys!
Tread Lightly! certified Tread Trainer

Search 100+ Toyota tech sites, including this one: All Toyota Search Engine
WATRD is offline   Reply With Quote
Old 05-09-2005, 06:38 PM   #11
Registered User
Personal Sales Rating: (0)
 
DealMaker's Avatar
 
Join Date: Oct 2004
Location: coastal L.A.
Posts: 990
Quote:
Originally Posted by bike4miles
There is concreat inside the Hover Dam that is still drying according to my Engineering 211 (statics) instructor. The thicker it is, the longer it takes. The Hover Dam is the tickest chunk of concreat on the planett and will likely take hundreds of years to cure compleetly.
The Hoover Dam was poured in hundreds (thousands?) of small, interlocked, "pour" sections about 3-4 ft. deep, I believe, and not in one big pour. Anotehr bit of Hoover trivia, the base of the dam is about as wide as the dam is tall. There is an awesome Discovery Channel show about the Hoover Dam that makes the rounds every few months or so. Quite a fascinating bit of engineering, and done pre-computer era.

Edit: I guess someone beat me to the trivia. Someday I'll remember to read all the posts befre replying.
__________________

'04 4Runner 4X4 SE V8
BFG KO 265/70/17 - Donahoe Coilovers - Deaver rear springs - Bilstein 7100 shocks - Hanna Sliders - Shrockworks Front Bullbar

Last edited by DealMaker; 05-09-2005 at 06:42 PM.
DealMaker is offline   Reply With Quote
Old 05-09-2005, 07:04 PM   #12
Contributing Member
Personal Sales Rating: (0)
 
RED 85's Avatar
 
Join Date: Apr 2004
Location: Parker, CO
Posts: 942
Yeah but is some BODIES in the dam or not?
__________________
Brandi
You heard of the boy named Sue, Well I'm a man named Brandi!

'85 extra cab pick-up, Up on blocks waiting for time and money.
'85 4-runner with 3" lift, 33's, 4.88's, rear ARB (still trying to get air to it), Downey intake with K&N filter, some type of header, Camo Int.
RED 85 is offline   Reply With Quote
Old 05-09-2005, 08:23 PM   #13
Contributing Member
Personal Sales Rating: (0)
 
arjan's Avatar
 
Join Date: Sep 2002
Location: Mission, British Columbia
Posts: 1,608
Quote:
Originally Posted by DealMaker
Anotehr bit of Hoover trivia, the base of the dam is about as wide as the dam is tall.

Quite a fascinating bit of engineering, and done pre-computer era.
As wide as it is high, is essentially a the same idea as a pyramid. Not a whole lot of engineering to that.
The Egyptians have been building those for a while .

Just pulling legs
__________________
2006 4Runner V8 Sports Edition
2011 Dodge Ram Sport
arjan is offline   Reply With Quote
Old 05-09-2005, 08:30 PM   #14
Registered User
Personal Sales Rating: (0)
 
DealMaker's Avatar
 
Join Date: Oct 2004
Location: coastal L.A.
Posts: 990
Quote:
Originally Posted by RED 85
Yeah but is some BODIES in the dam or not?
According to the show, there are no bodies buried in the concrete. However, the loss of life during the construction was huge. No OSHA, etc.
__________________

'04 4Runner 4X4 SE V8
BFG KO 265/70/17 - Donahoe Coilovers - Deaver rear springs - Bilstein 7100 shocks - Hanna Sliders - Shrockworks Front Bullbar
DealMaker is offline   Reply With Quote
Old 05-09-2005, 08:44 PM   #15
Registered User
Personal Sales Rating: (0)
 
kyle_22r's Avatar
 
Join Date: Mar 2003
Location: Lacey, WA
Posts: 3,981
generally i thought when doing something on that big of a scale, they don't even bother stopping the pour if somebody falls in. reasoning being that they're already gone...
__________________
1998 tacoma, 3RZ-FE, 5 speed, 30x9.5R15 M/Ts

past toys:
1984 4x2
1979 4x4
1991 4x4
kyle_22r is offline   Reply With Quote
Old 05-09-2005, 09:34 PM   #16
Registered User
Personal Sales Rating: (0)
 
wimpywade94's Avatar
 
Join Date: May 2003
Location: benton city wa
Posts: 1,320
Quote:
Originally Posted by kyle_22r
generally i thought when doing something on that big of a scale, they don't even bother stopping the pour if somebody falls in. reasoning being that they're already gone...

Wouldnt that suck to get knocked out and in,

talk about a horrible way to go.
wade
__________________
86 runner, rebuilt motor, egr block off, headman header, 3"bl, 33x12.5 m/t's. Lots of work wanted to do. limited skills, funds, time and drive.



If you dont know where your going, anyplace will do.....
wimpywade94 is offline   Reply With Quote
Old 05-09-2005, 10:53 PM   #17
Contributing Member
Personal Sales Rating: (0)
 
bike4miles's Avatar
 
Join Date: May 2004
Location: Tucson, AZ
Posts: 3,401
Send a message via Yahoo to bike4miles
Quote:
Originally Posted by bike4miles
There is concreat inside the Hover Dam that is still drying according to my Engineering 211 (statics) instructor. The thicker it is, the longer it takes. The Hover Dam is the tickest chunk of concreat on the planett and will likely take hundreds of years to cure compleetly.
Yes, drying was not the corect term. I should have said cured. BTW I heard from a civil engineering student that concreat cures faster and deeper under water.
__________________
--Miles
Sold
'91 4runner, 22re, 5 spd manual, 180,000 miles,
cone filter, Downey 1.5"HD coils, SkyJacker Nitrogens, Magnaflow Exhaust, Stull grill, Clears all around. Check out my sound proofing project and other mods:
My 4runner page

My 2006 Camry page

I'm a Myspace Addict!
bike4miles is offline   Reply With Quote
Old 05-10-2005, 05:08 AM   #18
Contributing Member
Personal Sales Rating: (0)
 
CynicX's Avatar
 
Join Date: Jul 2004
Posts: 2,370
I busted an old concrete staircase on the side of my house and I busted up a relatively new sidewalk that connected too it....the staircase was probably 60-70 years old then sidewalk was 4....since the sidewalk used a more modern mix it was alot more difficult to to bust up compared to the stairs....and the sidewalk interior center was just as hard as the extirior surface....

Oh I saw a show on the Hoover damn, they said a body in the conrete would comprimise the strength of that section so they said that was a major concern and there is no known bodies in it.....I dunno though.....
CynicX is offline   Reply With Quote
Old 05-10-2005, 06:42 AM   #19
Contributing Member
Personal Sales Rating: (0)
 
MTL_4runner's Avatar
 
Join Date: Jul 2003
Location: Montreal, QC Canada
Posts: 8,807
Send a message via AIM to MTL_4runner
Quote:
Originally Posted by bike4miles
Yes, drying was not the corect term. I should have said cured. BTW I heard from a civil engineering student that concreat cures faster and deeper under water.
Concrete cures better with water present which is why you always need to keep it wet while it is going through the initial curing process (ie if you pour a slab you need to keep hosing it down every day). Therefore if it is underwater, it should cure more thoroughly (I don't think it would cure faster, but not sure on that) and you should end up with a stronger product due to fewer crack flaws. Many slabs are actually flooded after setting to ensure a strong final product.

http://www.concretenetwork.com/concr...abs/curing.htm

Click the image to open in full size.

"After concrete is placed, a satisfactory moisture content and temperature (between 50F and 75F) must be maintained, a process called curing. Adequate curing is vital to quality concrete.

Curing has a strong influence on the properties of hardened concrete such as durability, strength, watertightness, abrasion resistance, volume stability, and resistance to freezing and thawing and deicer salts. Exposed slab surfaces are especially sensitive to curing. Surface strength development can be reduced significantly when curing is defective.

Curing the concrete aids the chemical reaction called hydration. Most freshly mixed concrete contains considerably more water than is required for complete hydration of the cement; however, any appreciable loss of water by evaporation or otherwise will delay or prevent hydration. If temperatures are favorable, hydration is relatively rapid the first few days after concrete is placed; retaining water during this period is important. Good curing means evaporation should be prevented or reduced."


BTW I highly doubt a normal sidwalk is still soft inside after a 1 year curing period....I think someone's leg was getting pulled there. Remember that typical concrete needs to have a compressive strength of 3000-4000 psi and if it is soft in the middle there is no way to get there on a small piece (the larger the pour, like the Hoover Dam, the more tolerance there is to uncured sections beause of load distribution). A large bridge also might be a different story, but would depend on if it were poured in place or made from prebuilt components and what volume of cement was poured. Also keep in mind the higher strength the concrete is (ie lower porosity) the longer it will take to cure.

Here's a bit more on hydration too:
http://matse1.mse.uiuc.edu/~tw/concrete/prin.html
__________________
- Jamie

1996 4Runner SR5 4X4 Auto

Deckplate Mod, Hayden Tranny Cooler, Amsoil Air Filter, OME 881/906 N86C/N91SC Lift

Best OBD II scan tool I have used!.

.....and I am AMERICAN!

Last edited by MTL_4runner; 05-10-2005 at 09:31 AM.
MTL_4runner is offline   Reply With Quote
Old 05-10-2005, 07:13 AM   #20
Registered User
Personal Sales Rating: (0)
 
farmerj's Avatar
 
Join Date: Dec 2004
Location: Central Minnesota
Posts: 469
It is capable of walking on it the matter of a couple of hours really.....

Click the image to open in full size.


As you are finding out, It doesn't dry, it cures. The other are giving you a pretty good explanation here. Chloride can be added to concrete for the initial set-up, generally if you are expecting cold or freezing tempuratures with the first 28 days. These are the most critical really. Curing the concrete correctly in those 28 day is critical also. Too much heat or wind will suck the moisture out of the concrete.

As concrete ages, it will get harder. Another thing that would make an old sidewalk "easier" to bust up would be salts and chemicals in the enviroment. Part of the reason that shop floors need to be sealed is to keep the chemicals out of it.
__________________
Life is too short to have to work....

RIP - 4 July 2008 - '88 4Runner, Audiovox Cruise Control,Valvoline Full Synthetic Gear oil, SR5 instrument cluster, '95 4Runner Seats, Rear U-bolt Flip
farmerj is offline   Reply With Quote
Old 05-10-2005, 07:13 AM
Yotatech
4WD Truck




Paid Advertisement
Reply

Tags
cement, completely, concrete, concretedryingposts, cure, dam, dry, drying, faster, harden, hoover, long, quickly, set, time

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
home improvement question- what to do about this concrete? Bob_98SR5 Off Topic Talk 32 02-25-2007 05:32 PM
fixing a bad concrete patio job Bob_98SR5 Off Topic Talk 15 04-19-2005 10:26 AM
Concrete floor covering.Opinions??? FilthyRich Off Topic Talk 15 01-07-2005 01:44 PM
How do I remove concrete sealer? mangoango Off Topic Talk 1 09-08-2003 12:20 PM
How can I remove oil from concrete? jimrockford Off Topic Talk 6 05-22-2003 05:27 AM


All times are GMT -8. The time now is 04:24 AM.


2010 InternetBrands, Inc.