Acrylate Resinous Grout Systems- Solutions for Stabilizing Soil and Sealing Leaks

Resins that are chemical grouts are the perfect example of science and engineering going hand in hand.

Grouting” describes the art — and science — of injecting a grout into soils, fissures and concrete cracks for stabilizing soil, sealing leaks and repairing structures. Chemical grouts are chemicals, both organic and inorganic, that can undergo the phase transformation from liquid to solid accompanied by the enhancement of their physical and mechanical properties during the curing process.

What’s in a Name?

In current common usage, grout materials are typically distinguished into two broad categories — chemical grouts and cement grouts. From a chemistry standpoint, however, this is an artificial distinction: Both undergo a chemical reaction. The curing of most cementitious grout systems is driven by the pozzolanic activity, which is how cementitious materials go from a liquid to a solid. Chemical grouts can be organic or inorganic based on the raw materials that make up the primary reacting resins and transform through a reaction triggered with an activator, sometimes water.

That said, we will observe the common usage here of “chemical” grout as we explore the development of acrylate resinous grout systems.

Chemical grouts are currently used for a number of structural, geotechnical and environmental applications. Some of the most common applications include soil stabilization, void filling, sealing leaks and lifting slabs.

Selecting the Right Product

Several factors dictate the selection of a grout for the desired application. For instance, soil stabilization by grouting requires considering the type of soil and its properties such as density and porosity, as well as the soil area and depth to be stabilized, and the water table depth.

The field conditions and requirements go hand in hand with the resin selection. The field conditions have a pivotal role to play.

For example, since most of the chemical reactions enabling the phase transformations are exothermic in nature, a chemical grout that has a gelling time of five minutes at optimum conditions could be used in a hot tropical climate, though the set time may be marginally shortened as the field temperature might be higher than the optimum. That same grout may not be appropriate, however, when the conditions are below the optimum temperature because the set time may be increased due to low field temperatures, which could result in excessive seepage of the grout outside of the area to be treated. Similarly, if this same resin is thin and easily flowable, it may not be a good option when the soil strata to be stabilized is shallow since the area to be grouted is often not a confined space.

Research and Development

Given the technical limitations and toxicity issues of acrylamide grouts and the need for flexible grouts with a wide adjustable range of set times, research and development in exploring the capabilities of acrylate resinous grout systems is under way.

Acrylate Resins as another Option

Contractors and engineers who need a flexible, elastomeric grout for wet environments and want a wide adjustable range of set times should consider acrylate chemical grouts, which are acrylamide-free. They provide an excellent alternative to acrylamides, which are not permitted in many instances due to their toxicity. The adaptability of acrylate grouts in varied environmental conditions along with their performance make them another tool available for infrastructure repair projects.