Concrete Cracking Issues

By TAC

Date 03-12-2013 16:33

Photos?

By G.S.Crisi (****)

Date 03-12-2013 18:54

I think that your question should be posted on the site of the American Concrete Institute (www.concrete.org) and/or the site of the American Society of Civil Engineers (www.asce.org), rather than this Forum.
Giovanni S. Crisi
Sao Paulo - Brazil

By Cumminsguy71 (*****)

Date 03-12-2013 23:44

Did you have drainage at the posts in the holes for the legs to drain out condenstation?

Improperly mixed, improperly cured all manner of things as you have found out. I have not had issues with any of my cored posts but using "Quik Roc" brand.

By Smooth Operator (***)

Date 03-13-2013 00:01

Yombo, Have run into this problem before........ I was LUCKY and it wasn't on my job originally.... Handrail sub went belly up but a the contractor that held the bond was still on the hook for repairs :eek:

Ends up you have to be VERY CAREFUL what type of grout you use !!!!!!!! :confused:

Talked to R.B. Wagner about the situation and found out you have to use" ROCKTITE GROUT FOR OUTDOOR USE" :roll:

( yes they make two different types / white 5 gal. bucket with RED lettering is indoor, BLUE lettering is outdoor, even says so on small lettering on label) :surprised:

Ingredient in indoor grout ABSORBS moisture (can't remember what it is) :red:

but it causes expansion of hole and starts the cracking :eek:

Another tip is NEVER build grout up outside of hole (grout needs to be contained by sides or it will crack/peel off) always leave grout 3/4" - 1/2" low from top of hole and after it sets take a cauk tube of concrete crack sealer ( needs to be self leveling type) and fill hole to top :cool:

ALWAYS get complements from owner/G.C. on this finish!!!!!!!! :cool:

Sorry I can't remember that ingedient but I always wondered?????????, WHY MAKE TWO DIFFERENT TYPES OF GROUT :yell:

There is another grout I have used (that contains an epoxy) that is DOT approved is a little cheaper than Rocktite but it takes forever to set up!!!!!!!! :sad:

so I don't use it much........ If you turned in cut sheets and got approval on the grout you shouldn't be in a jackpot :eek:

but check for that ingedient!!!!!!!!! you'lll have found your/ architects problem :razz:

By yojimbo (***)

Date 03-14-2013 01:00

Guys,

Thanks very much for the replies, a lot of usefull information. I'd like to leave a few responses to your input. As to photos, sorry, can't bring myself to do it. The pretty little railings look nice, smooth, straight, square, level. plumb and to grade, but the cracking is HORRIBLE. Imagine a smack with the Ugly Stick to a pretty face and you've got the picture. Really heartsick about it, seeing good work marred up. Giovanni, you are correct, The American Concrete Institue would be the forum, I had already looked them up in hopes of speaking with an engineer to get some insight and maybe a better determination of root cause, called the main office and was refered to a local chapter phone line that didn't pick up. Seems like a membership with them may be required to access anything valuable but I will be pursuing it. As to the grout used, the cut sheets for the product were submitted and approved, Sakrete, and what was used, but suggestions for an alternative to use in the future is appreciated. The next big project just getting started is a DOT railing job, 2080 LF, posts every 5'. The contract documents were typical bueracratic, unreviewed, rubber stamped, insert incorrect specification here, and cross reference it elswhere with something different. The plans on this one call out Epoxy Resin [Big Dollar Stuff] on one sheet, Epoxy Grout on another sheet, and the Special Provisions specify Epoxy Grout [Real Spendy] and then gives a spec number for a Type IV Multipurpose non-shrink mortar grout, the normal stuff. Guess which one got used for bid? Yup. Go to the Qualified Product List, the DOT webpage listing of approved products, pull up the Hilti product that's been approved and use it during original pre-con meeting, then submit it with shop drawings and it gets approved. One large difference is the DOT job will be using sleeves set in the concrete, I provide/GC places, and the railing is embedded using grout in those. My gut tells me that is a far less dangerous path to tread in regards cracks. The sleeves should provide sufficient expansion while the concrete cures and setting the rails after that will pose less risk.

Smooth, very much like the partially filled grout option with a sealer cover, I'm sure it give a very nice finished look. Problem with guvmint work would be getting approval. It would require extensive engineering submittals, out of my pocket, and even then an act of congress or a revision of all Calculus assumptions to get it approved. DOT engineers are VERY careful about exposing their well paid positions to unknown factors. Which is, I suppose as it should be. They build our bridges, we want them to be carefull and know what they are doing, and they're spending our money so we have a right to get what we paid for even when it's just some pedestrian railing that needs to be set in place and take a 50# concentrated load. The process can get a little irritating, what with the endless daisy chain of emails sorting out the most picyune details, or needing to explain to qualified engineers something as basic as a geometric impossibity [think 10# of dung in a 5# box], they get it finally and see the light and things move forward, but at a snails pace. So it can be frustrating. In the end though, when I've had a chance to communicate directly with any of them, and cut through some of the red tape or protocol which causes so much confusion, they have all been great guys, smart, easy going, practical and mostly with real good senses of humor. Ain't met a miserable one yet in the bunch.

Finishing up some refrigeration piping this week and just got home with the Crack Issue weighing heavally on my mind all day and talked with the insurance agent. Turned out to be very reassuring. The product completion liablilty on my insurance is there for exactly this kind of occurence. Should it come to a lawsuit, the insurance company sends in the lawyers! Hot Damn! At least that potential money drain aint gonna bleed me dry this week. Really took some weight off. Beyond that, every single concrete contractor/ core drilling-cutting contractor I've spoken with [now counting 6] has told me the same thing- It ain't my fault. Further, they've all said the same thing: the plans called out a 3" core, 3" off the edge of concrete, leaving a 1 1/2" critical edge distance and that's too close, cracking was going to occur. At a pre-con on that job, I reccomended sleeving the holes to the architect and he wouldn't have it. Questioned the coring schedule to be done in less than a 28 day full cure and was told the concrete was good to go. Used the stuff they approved, Sakrete, and now getting questioned on it with bad juju liabilities hanging around. Sometimes this racket just feels like a warzone.

Maybe I worry too much. I like to think it's just being concientious. Cover all the bases, make sure everyone knows the risks and whats up. Piss of GCs and project managers with details they don't want to bothered with trying to keep them from coming back to bite them or me. Thankless bastards some of them. The good ones, get you paid on time, express a token of appreciation for the save their ass value added engineering you suggest that saves them 10 grand or 20 in manhours or warranty work seem a little far between tonight. The smug bastard making trouble with me now is no one I trust, so I'm not counting chickens or thinking I'm out of the woods, just gonna keep on keepin on. Only thing I'm sure of tonight is you gotta be able to look a man in the eye and know you did the right thing. Like that guy said, "It's a good life if you don't weaken".

Thanks for letting me vent fellas.

By Smooth Operator (***)

Date 03-14-2013 02:10

yojimbo, MOST G.C.'s you can't trust as far as you can throw them!!!! :yell:

They don't pay atttention let alone pay their bills....... LOOK real hard for any reason to backcharge, deduct or even withhold your payment..... :eek:

In 30 plus years of biz. I can count on one hand the number of G.C.'s I'll work for :roll:

In this biz. you have to be very picky who you work for!!!! Thats why all big jobs have bonds..... If you have the proper insurance your arse will be covered and the G.C.'s insurance also will get involved..... :sad:

When the lawyers get involved, really won't matter who's at fault a deal/agreement will be hashed out and that will be the end of it......... The longer your in biz. the more chance your gonna use that insurance......(just had a claim because 75 weldments ( 45# ea.) walked off the job while being installed by a sub and I withheld $7500.00 from his contract till he filed a police report/ sueing me for payment so I turned it in to the insurance co.) AIN'T BUSSINESS FUN :confused:

By yojimbo (***)

Date 03-14-2013 02:50

Smooth

Fun? Yeah, like root canal and the dentist is out of novacaine. Debating the strategy/tactics. Proactive or wait and see. Gonna have a concrete guy look at it and give me a price so I can come back at the GC should he try jack it and at least know what the real cost would be compared to legal fees. On a technical note, whats your opinion regarding sleeves compared to core drilling. Does it minimize cracking risk or not effect it . Thanks dude.

By Smooth Operator (***)

Date 03-14-2013 22:50

Yojimbo, My experience w/ sleeves is..... The concrete guy isn't worried/care about placing sleeves , he's just worried about placing and finishing the cement before it sets.... :eek:

First they aren't placing them plumb...Second the spacing between posts ain't gonna be equal and there goes your PROFIT...... :yell:

Because lf your making 38"panels and now you have one at 37 1/2" you got problems :roll:

Ends up you will be core drilling anyway :cry:

only now you ain't gettin paid to do it :razz:

(best sleeves i've seen are empty beer/pop cans.......) :cool:

By yojimbo (***)

Date 03-15-2013 00:23

Smooth,

Bad sleeve placement has been my experience as well. Early on did a 180 riser stairway with, I don't even remember how many sleeved posts. Off by INCHES some of them. Totally fubared. Took a greasing on that one and swore off sleeves forever. Made every hole by the way, but it took a whole lotta field measuring, screwing with the table layout and sweating every fraction of an inch. The upcoming job prohibits core drilling, sleeves are mandatory, and the GC will be setting the sleeves, roughly 400 of them. The issue has been discussed with the PM, he is aware and experienced with the risks, but I've yet to broach the costs for misplaced sleeves with him. In this case it's going to be a little more straightforward for me. It's a DOT job for one, all the fabrication gets inspected before it goes to coating and the inspectors have been cool so far on a job from last year, but only because every piece of railing was built exactly how it was shown in the shop drawings. Zero deviation policy. So, there is no opportunity for misplaced sleeves, the drawings would need to be revised and approved, delays, impact, additional costs, ectcetra. As it stands, the GC is on the hook for correct placement, which I have indicated would be best handled with a coordinated single point of contact person of responsibility, as in, put me in touch with your forms/carpenter foreman, we will go over the drawings for each wall, and then the ball is in their court. Fortunately, the job is only 2 miles from the shop and I will be able to do quick checks to confirm placement and give a heads up if I find error, but in the end it's their responsibility and they will be charged accordingly if their work is out of spec. Providing the sleeves will be first order of business on parts production and should start in about 10 days. Will be having a talk with PM then. Still researching what forces are involved in the cracking issue on the job with problems and their effect on sleeves. The question is if the sleeves, poured in place and after cure will sufficiently resist and positive expansion forces from the grout, which while minor are inevitable acording to the manufactures, to the order of .03- .08%.

By Cumminsguy71 (*****)

Date 03-14-2013 02:55

Sounds like a heck of a mess you got, three different things for the original plan....or was it four?? LOL!! Why can't they just pick one? They're supposed to be the engineers, designers on big projects and they just leave it open ended.

By DaveBoyer (*****)

Date 03-14-2013 04:16

My friend with the garden center had to rework an old porch to include a wheelchair ramp for a new tennant. He used a Sakrete product in sonatubes to make pillars for the new porch posts to rest on.

The Sakrete didn't cure properly, never got as hard as it should have, but expanded enough to jack the porch up about 2" from where it was when the Sakrete was poured.

Sakrete's waranty was limited to providing new bags of product...