25 x 25 Concrete slab with crazing cracks 1

[k1e2v3i4n5]

Hello, i have a problem with crazing through an entire 25' x 25' concrete slab, poured in October 21,2004 (max temp was 60 - min. temp was 46 right through the 31st of October). my concrete bill states 11 cu. yards, 3500 pea with 1% daracell (i believe)it's hard to make out if the second letter of daracell is an a or o, and fiber mix. The contractor is saying that the mix can't be right and the concrete company is saying that the application had to be wrong. this is leaving me no where in regards to resolving this issue which in my opinion can only get worst in regards to the cracks... the other issue is discoloration of the concrete suface that is very unsightly, but not my major concern right now. my question is how do i determine if i received the correct mix or if the appliaction was not proper. i was at the site the whole day and saw everything step of the process if that helps, i can answer any questions in regards to what i saw regarding the forming, pouring and floating of the slab. any suggestions would be highly appreciated...

 

[dbuzz]

A primary cause of craze cracking in floated concrete slabs is over-troweling and a secondary cause is inadequate curing. The concrete mix may have been a contributing cause if there was a high water-cement ratio combined with a cement-rich mix.

These may be a moot points. If you had a single contract with the Contractor and he had a sub-contract with the Supplier it would seem to me that the Contractor is responsible to you for the entirety of the installed works. If this is the case, don't become the umpire in a "he said, she said" argument between the two parties. Have a look through your contract. See a solicitor if you need to. Take action against the Contractor. He may take action against his Supplier at a later date.

If you had separate Contracts with the Contractor and Supplier, then you may be in a more difficult contractual situation. Did the Supplier take test cylinders at the batch plant? Did the Contractor take test cylinders at the site? What do the test results indicate? Who was responsible for accepting the concrete at the site?

 

[k1e2v3i4n5]

dbuzz, thank you much -- that's was initially my position until the contractor brought the supplier to discuss this matter with me. i will definately take the position that you suggest here and remove myself from any further discussions with the supplier because my contract was not with the concrete company. my contractor ordered the concrete and instructed me to pay them cash on delivery and i complied.

If anyone can suggest what are my alternatives to correct the physical problem of the crazing cracks, that will be appreciated much. i'm thinking at this point that the slab will have to be removed and replaced. i did read that there was a product to cover, seal and hide the crazing cracks but i'm not so certain about the application, cost, or reliablity of any such product... i would like to hear suggestions on the best way to reapir this situation please.

 

[towerhill]

If you find the concrete and placement are adequate and follow the project specifications, also review what (if any) additional cure and sealer product or finishing formulas where added to this slab. A poor quality sealer and application can be the root of these cracks especially for such a small area assuming a 5-6" thickness?

 

[JConc]

Crazing cracking tends to be unsightly only, the service life of the slab should not really suffer. Crazing [ is somewhat common] is a finishing issue and is more noticeable when an accelerator [Daraccel] is used. As far as hiding it, most people don't. A concrete stain may work from Sherwin-Williams, Home Depot etc., but may not last if heavy traffic.