A joint is basically a controlled crack in the concrete. There are mainly two kinds of joints that are placed in concrete. One would be an expansion joint and the other would be a control joint. It is always a good idea to caulk or seal all joints regardless of the type. Water that gets into the joint can cause concrete settling and if the water freezes, it could heave or damage the concrete.
An expansion joint is designed to allow the concrete to properly expand and contract during the seasonal cycles without creating a bind. An expansion joint can be identified because it usually contains a piece of expansion material such as asphalt board, plastic or wood. Without properly placed expansion joints the concrete has no room to expand and typically will crack to relieve the created stress.
A control joint is a joint that is placed in the concrete to create a flaw and relieve stress points. A control joint can be tooled in while finishing the concrete, or can be saw-cut in later. Control joints additionally allow the concrete to shrink during the hydrating process. The only problem with saw cutting the control joints is that the sawed joint cannot be placed until the concrete has already substantially dried leaving no place to direct shrinkage. This may be too late to prevent unsightly shrinkage cracks. A tooled joint being already in place gives the shrinking concrete a given path to crack in and if properly placed prevents noticeable shrinkage cracks. Without proper control joints concrete will have shrinkage cracks.
Mudjack Mania mudjacking services, has attempted to list most of the common concrete problems, along with some basic explanations of the common causes, here in and around Oklahoma City. We also included some pictures to further help you identify what you may be seeing with your concrete. Obviously we are not able to list everything, but hopefully we listed what will help you. If you have questions, or need further assistance identifying your concrete problems, feel free to Contact Us for a free estimate and evaluation.
There are a lot of problems with concrete, but there are also a lot of solutions. We realize that we can not cover all topics, but we hope this information was helpful to you. Many time your existing concrete can be repaired for a fraction of the cost of replacing it. although Mudjack Mania mudjacking services, does not offer a lot in the way of concrete repair, we do have extensive knowledge about concrete repair and are willing to offer you some sound advice. Additionally, just because someone decides to remove and replace their existing concrete, does not mean they won't find themselves in the same boat in a few years. New concrete is not exempt from ground movement and freeze thaw cycles. And, if the new concrete contractor fails to properly install the control and expansion joints, the new concrete owner will soon be unhappy. If you have questions about your concrete and would like a professional opinion, feel free to Contact Us for a free estimate and evaluation.
Discoloration can be caused by many things from chemical stains to an entire array of circumstances. Some of the most common would be caused by something laying on top of the concrete during the hydration period. Any concrete poured in the winter season and subject to freezing temperatures prior to being cure must be protected. To protect new concrete, the most common thing used by concrete contractors are thermal blankets. These blankets do a very good job in protecting the concrete from the cold, but often because they touch the drying concrete unevenly, they leave discoloration.
Another source of discoloration that is often overlooked, is caused during the mixing of the materials. In a perfect world the concrete truck would have the water placed in it and then the cement. The rock and sand are typically wet and are then added to the mix. If some of the rock was dry it would absorb more water from the truck that an alike rock that was already wet. This water in the truck having already been mixed with the cement powder and any concrete color being used, would be darker than the clear water used to wet the rock. Therefore during the hydration process, the dry rock would produce more darker water than the wet rock, creating a darker spot in the concrete. Decorative overlays can hide and beautify discolored concrete. If you have questions about discoloration, feel free to Contact Us for a free estimate and evaluation.
Heaving can occur when the soil expands and lifts the concrete from its desired position. This could be do to unexpanded clays getting wet and expanding, or wet soil freezing. Another common cause of heaving is a tree that is located too close to concrete paving. The roots grow under the concrete and as they grow larger, the concrete is lifted out of its original position. Heaved concrete can often be repaired by mudjacking the concrete around the area that has heaved. In some cases where the surrounding concrete cannot be lifted, the heaved concrete can be ground down to match the adjacent concrete. If you have questions about concrete heaving, feel free to Contact Us for a free estimate and evaluation.
Flint pops are caused by a piece of flint rock being located too close to the surface of the concrete. This is typically the direct result from the installers failure to tamp the concrete. As the sun heats the concrete a flint rock may become too hot and subsequently pop like a piece of popcorn. This action will result in a divot in the concrete surface that can be identified by the presence of a flint rock showing in the bottom of the divot. If you have questions about flint pops, feel free to Contact Us for a free estimate and evaluation.
Although settling may occur for many reasons, most settling is a direct result from ground movement and /or improper compaction prior to pouring the concrete. There are other causes for concrete settling. One would be long periods of drought, that dry out the soils along the concrete edge and allow the concrete to drop. Once this occurs it can not be reversed by watering the soils. Another cause can be our almost continuous earthquakes jiggling the soil. Most of our soil here in Oklahoma is not that stable to begin with. So when you combine an area of questionable compacted fill, with a lot of jiggling, you get concrete movement. Then there are the occasional Oklahoma floods. They can make it clear why sand should not have been placed under your driveway. And we can't leave out the freeze thaw cycle. As the ground freezes and thaws it changes in size. Farther north this problem alone causes people to have to re-level their concrete every few years.
Concrete settling may result in dangerous trip hazards and spoil an otherwise sound concrete structure. Most settling can be easily repaired by mudjacking. To learn more about mudjacking, follow the link to Mudjacking 101, or simply Contact Us anytime for a free estimate and professional evaluation or your concrete.
Concrete may delaminate for many reasons such as being allowed to freeze before being cured, but the most common would be a result from craze cracking. In an area subject to freeze thaw cycles, water that has entered the small cracks freezes and expands. This enlarges the cracks allowing more water to enter. This action will continually accelerate until the concrete surface has eventually delaminated. An acrylic overlay can fill already delaminated places and often prevent further delamination as many of the acrylic surfaces are not porous like the concrete. Some of these can not only fill and bond the craze cracking, but additionally can block out any water that could do further damage. If you have questions about concrete delaminating, feel free to Contact Us for a free estimate and evaluation.
There are many reasons why concrete cracks. Problems ranging from unstable soils to improper finishing are just a few. So many factors come into play that sometimes it is not obvious what the actual cause is, but sometimes the first step is to try and identify the cause. Below is a brief description of the most common types of cracks. Hopefully this will assist you in identifying yours.
Structural cracks can be described a failure in the intended design of a concrete structure. A structural crack will typically cause other problems. Although there could be many reasons why concrete could have a structural crack, most can be contributed to something happening that was not originally anticipated, such as settling or soil expansion. Structural cracks can often be cross pinned and filled or epoxy repaired, but without relieving the stress or solving the structural problem, it is likely that the concrete will fail again.
Shrinkage cracks are a natural occurrence in concrete. As the concrete dries and the water hydrates out the concrete becomes denser and smaller. As the concrete shrinks, it will be forced to gap. If control joints have been placed properly the concrete will use these joints as its crack points, eliminating unsightly random shrink cracks. Shrinkage cracks can typically be filled or epoxied. As long as there are proper control and expansion joints, this type of repair, if done correctly, is typically permanent.
Craze cracking is a phenomena caused by the concrete installer trowelling the bleed water back into the surface of the concrete. This results in the concrete surface containing much more water than normal. When the concrete hydrates the surface will shrink much more than normal creating a spider web effect of tiny cracks on the surface of the concrete. These small cracks often later result in delamination of the concrete surface. An acrylic overlay can fill already delaminated places and often prevent further delamination as many of the acrylic surfaces are not porous like the concrete. Some of these can not only fill and bond the craze cracking, but additionally can block out any water that could do further damage.
If you have questions about cracks in your concrete, feel free to Contact Us for more information.