Why does cement crack?when newly layed & what is its remedy after this has happened?
Answers:
the exterior dries too fast while the inside is still wet, after you pour it lightly hose it over every hour for a day, this should keep the outside wet enough while the center drys!
Different cements need to be a certain thickness or they will crack. The best thing to do is look up how thick you should be laying out the type of cement you have.
could be a bad bag of cement
There are many reasons, from poor drying and improper mixture of materials to a poor base and or supports such as rebarb.
Not much you can do for a crack. If it gets worse you need to cut that section and replace with new concrete.
As the cement dries often spider cracks will form near the surface. One way you can stop this from happening is to keep the surface of the concrete slightly moist.
Spray it with a fine mist every hour or so as it hardens up.
Cement cracks under its own weight. When the dirt under the slab settles, it looses support in certain areas. There really is not much you can do after the fact. However, when you pour the slab, you can insert what is called a control joint. With this you basically force the slab to crack where you want it. If you are desperate you can e-mail me at dustin00420@yahoo.com and I can provide you with the information on how to create a control joint.
Usually if it cracks right away it was a bad pour or they didn't use any gravel below, before they poured it. All concrete will crack.Depending on what part of the country you live the standards for a good pour are different because of the Cold. Check with the local Contractors Union.
You can either dig it up and re-pour or use a concrete filler to repair the crack.
>> http://www.concrete.com/cgi-bin/ubbcgi/u.
>> to repair>> http://www.easy2diy.com/cm/easy/diy_ht_i.
Good luck
It has to have reinforcement in it like rebar or wire mesh to help hold it toghter, and then in the finish or after its hard enough relief joints must be cut for expansion 8-10' apart or depending on the size of the slab. That way when it cracks it will be on that joint. As for fixing the cracks? no real way, just put a "bandaid" on it with hydrolic cement or caulk.
The solidifying process in concrete produces or expresses a lot of heat; this expands the material as it sets then contracts as it cools.
The solution to unsightly cracks is to cover with a thin layer of slurry cement. The large projects like the Hoover Dam use cooling pipes in the concrete, abandoned in place. There are chemical additives that help in small work, like sidewalks, so you can float the surface, which fills in nascent cracks.
It cracks if it dries too quickly and cannot be remedied. leave it under a tarp to give it shade while drying and give the surface a dampening every hour or so, do not add too much water to start with or it will do more harm than good.
The answers post by the user, for information only, UKQnA.com does not guarantee the right.