A Long History of UDI Success
The use of high-density expanding polymer for concrete lifting was introduced in the United States in the early 1980’s by URETEK, with its URETEK Deep Injection® (UDI) application. The introduction of polymer technology revolutionized the concrete lifting industry by offering a faster, cleaner, highly controlled lifting solution. URETEK’s concrete lifting approach was conceptually the same as traditional mudjacking, but vastly different in technology, performance, and material capability. A closer look at older methods of slab lifting illustrate UDI’s success with these projects.
Traditional Mudjacking Method
Cementitious grouting – mudjacking – involves the use of a water/soil/fly ash/cement mixture injected by hydraulic pressure into the intersection of the concrete and base soils. The two basic components, a measured amount of water and a cementitious/fly ash mixture, are thoroughly mixed in a batch mixer, dumped into a hopper, and pumped under relatively low pressure by means of a positive displacement pump. The pump discharges into a flexible hose and the grout is injected through a pre-drilled 1/2” to 3” diameter hole using a special nozzle to inject the material between the slab and sub-base.
Although the concept and best practices behind traditional mudjacking methods are credible and still used today, the materials that are used with them often require lengthy installation times and do not stabilize the underlying soil, which is typically the source of the problem. As a result, these approaches (including “do it yourself mudjacking pumps”) yield a temporary fix which often result in a short life expectancy for the repair, and higher costs down the road when the issue is resolved on a more permanent basis.
The advancement of technology, knowledge, and specialized materials have vastly improved the speed, longevity, and effectiveness of concrete lifting and soil stabilization solutions, often exposing many of the weaknesses of older methods such as mudjacking. For example, cementitious material is slow to cure, and as it hardens it also shrinks. Once the cementitious material cures, it lacks sufficient tensile strength for long-term effectiveness. This is important when dealing with heavy dead loads, and especially with the concrete is exposed to live loads and vibration.
UDI vs. Mudjacking
UDI offers a number of advantages over mudjacking, including:
- Safe, low pressure injection of polymer under concrete slabs
- Rapid polymer expansion provides ultimate control for precise leveling.
- Material reaches 90% of strength in 15 minutes, asset can be used immediately
- Capable precision lifting, often to 1/8″ tolerance
- Small injection holes (5/8″) greatly reduces weakening the slab even more
- One-time cost for permanent repair
Traditional Mudjacking methods often involve:
- Improper mix design for applications in saturated soil environments
- Insufficient cure time (minimum 3 days, 7 days optimal)
- Constant vibration breaks the particulate bond of the slurry segregates paste and particles
- The additional weight of grout material over distressed base material diminishes any long-term expectations
- The hydraulically pumped slurry is difficult to control, increasing the risk of concrete breakage or “over-lift”
URETEK 486 Star® Polymer
URETEK 486 Star® is a two-component, high-density, expanding thermoset polyurethane system that is environmentally inert and completely non-toxic. These properties make it the ideal choice for environmentally friendly soil stabilization and concrete lifting projects. Best of all, it’s industry-leading hydrophobic properties resist the underground water erosion that leads to most settlement issues in the first place.
URETEK’s geo-polymer technology is based on chemical expansion pressure. The geo-polymer’s rapid cure time allows operators precise concrete leveling capability, virtually eliminating “over-lift” or risk of foundation damage. URETEK’s geo-polymer can be injected into a variety of saturated soil environments without losing compressive strength or structural integrity.
URETEK is The Trusted Vendor for Concrete Lifting
For over 30 years, URETEK has been a trusted, reliable partner for commercial enterprises, government officials, and private property owners faced with concrete lifting challenges. With its rapid response and experienced crews, URETEK is the vendor most prepared to restore valuable structures on time and on-budget.
Contact URETEK today to learn more about our industry-first and industry-leading UDI application. Also, see our case studies to read about how UDI has been successfully applied across the country, as part of large and small projects, wherever folks have had to deal with sunken foundations and settled pavement systems.