Mud jacking is generic term for slab jacking which is the process of lifting settled concrete by injecting or pumping cement stabilized material under the concrete and using the hydraulic pressure to fill voids and float or jack the concrete to the desired grade.
Those in the concrete business often refer to concrete as mud. However most Mud jacking does utilize top soil as the main body of the material. Sand and cement are added to provide a stronger and stable product.
The process of mud jacking involves drilling holes through the existing concrete surface to provide access to provide an injection port to the underside. It might require as many as 5 holes to properly raise and level a 10 X 12 driveway panel. The holes are placed for both lifting and void fill. The cement stabilized material is generally mixed on site and placed in a pump capable of producing a minimum of 200 psi.. The operator will move from hole to hole so as to gently raise the panel and ensure that all the void beneath the panel has been filled by forcing the material to come up through one or more of the neighboring holes. After the work is complete lifting materials are rinsed from the surface and the holes patched.
Although there are the scars/patches from the drilling or coring of the holes the end product is usually preferable to a budget concrete removal replacement job and for approximately 1/2 the cost and far less aggravation.
The process has been common place for many years. The parent company that we have worked with has been in business since 1946. Some have been around longer. The process has not changed a great deal. However some of the tools of the trade have improved significantly. There are electronic measuring devices and greatly improved survey equipment as well as more user friendly pumps. The process is as much an art as an concrete & mechanical engineering science so experience can make all the difference in the outcome.
The process is used common place in Mud Districts, Municipalities, County and State repair projects. Sidewalks, streets, drives, parking lots, warehouse floors, and equipment pads can all be improved by method of mud jacking. However the involved surfaces should be concrete. The process does not work for Asphalt.
The involved concrete must be an average to good product to start with. The involved concrete should have minimal cracks (some cracking is ok), reasonable strength and thickness for the intended use and preferably reinforced with re bar or wire mesh (reinforcing not required just preferred).
The process does offer some bonus to the environment as well as the pocket book. By saving concrete all of the pollution from the energy it takes to make the concrete components, ship them, demolish and haul off the old, prepare the site with forms and set the steel, as well as mix deliver, place and finish the product are saved. An average of 1500 to 2000 square feet of concrete can be mud jacked in a day for the same energy that it takes to handle the removal and replacement of 150 to 200 square feet of concrete. And there is very little down time.
I work for Concrete Raising Corporation aka CRC Houston. www.crc-houston.com