1 • US Grout Ultrafine VX extends the application of economical cementitious grouts over a broad range of soil types.
2 • Sand column testing is a dynamic way to measure grout performance. Again and again, US Grout Ultrafine (right column) demonstrated rapid and complete permeation ability at low PSI (8) using a standard 2 to 1 water/grout ratio.
3 • US Grout Ultrafine is placed using standard high-shear mixing equipment, pumps, and hoses.
4 • When poor soils need to be stabilized and strengthened, it’s rarely a small job. Cost is one of the areas where cementitious grouts really shine.
5 • Graph showing the geologic effectiveness of the various grout types.
IF A POTENTIAL BUILDING SITE is found to have existing soil conditions that do not support the project in terms of soil stability, load-bearing capacity, compaction requirements—or any of the other concerns brought on by poor native soil or underlying structure—the site need not be rejected outright. The right soil-permeating cementitious grout can cost-effectively bring the soil into alignment with the required geotechnical needs. Even sites that were built up using indiscriminate infill methods, soil types, and junk fills can often be stabilized and brought up to specification with a high-performance grout. Successful rehabilitation of those “brownfield” sites scores points in the LEED certification ledger as well.
DOWNLOAD: Cementitious Grout and LEED Certification White Paper.
Wide Geologic Effectiveness
Each year, at a Geotechnical Grouting Conference presented by the University of Texas-Austin, sand column tests are used to demonstrate the permeation ability of different grouts. The 2013 tests (held at the Colorado School of Mines) included a newly formulated cementitious grout designed with the flexibility to permeate various soil types—US Grout Ultrafine VX. This grout features the same impressive average particle size of 3 micros, but utilizes an adaptable liquid superplasticizer as an accelerant and dispersant.
Using a standard 2 to 1 water/grout ratio, and injected into a very fine colloidal silica sand, US Grout Ultrafine VX charged up the 60-inch sand-filed column in an unheard-of 80 seconds. The PSI at the pump was only at an eight when the grout hit the top (test allows for up to 10 psi and time allowance is 20 minutes). No other cement grout came close…not even when adjusted to a more favorable grout/water ratio.
The importance of such impressive permeation performance by a cementitious grout is welcome news in the grouting industry. Now, with US Grout Ultrafine VX, expensive, often short-lived chemical grouts have an adaptive cementitious brother that can effectively handle the toughest jobs.
DOWNLOAD: Sand Column Test Results Press Release.
DOWNLOAD: Geological Effectiveness of Grout Types.
The Key to Effective Grout Permeation
The key to effective soils permeation is this: particle size and rheology. Not viscosity. Particle size and rheology determine a grout’s ability to penetrate and properly disperse in soil.
The erroneous practice of tweaking the viscosity of a standard cementitious grout to amp injectability doesn’t work. It results in lower compressive strength and water bleed-off during crystallization, riving the grout seal with porous, interconnected wormholes and resulting in a poor, undesirable density matrix. As referenced above, the remarkable success of US Grout Ultrafine VX in the sand column tests and in the field is a direct result of the ultrafine particle size and the rheological properties designed into the grout formulation.
Not only do our cementitious grouts attain impressive soil permeation rates, they can do so even when using a reduced water-to-cement ratio that can achieve a compressive strength of over 8000 psi.
Extraordinary Grout Durability and Strength
US Grout products are the only pumice-pozzolan charged cementitious grout on the market. The pumice provides a second, complimentary reaction—a pozzolanic reaction—that adds an incredible performance boost to the standard water-cement hydraulic reaction that forms the binding concrete paste. Good things happen as the result of the pozzolanic reaction: the lifespan, strength, and the effective performance of the grout increases because the pumice (via the pozzolanic reaction it ignites) works to consume and convert the deleterious byproduct compounds that are produced by the cement/water hydration reaction, effectively densifying and tightly welding the cured grout matrix. This virtually impermeable grout can then resist the problems that plague ordinary cementitious grouts: no expansive cracking and failure from within, ultra-resistant to penetrating attacks from water and chemicals without.
Extraordinary Grout Longevity
The rheological properties of a grout are an important aspect of a grout mix design: properties like bleed, segregation, water/cement ratios, particle size and distribution of the cementitious materials. Higher strength grouts typically have low permeabilities and thereby resists chemical attacks and physical degradation. When the rheology is right for the soil structure, and, boosted by the grout-densifying pozzolanic reaction ignited by the pumice pozzolan, a US Grout product can effectively function for thousands of years.†
† Longevity projections from research referenced on pages 23, 26, and 78 of AECL’s Whiteshell Laboratories research findings and analysis on the ultrafine cementitious grout developed by the DOE’s Sandia National Laboratories. Also inferred from the practical proof of pozzolanic-charged Roman concrete.
Superior Grout Performance
Ask a geotechnical engineer to list the capabilities, performance results, and usage parameters of an ideal grout, and you would likely hear the following: wide range of water-to-cement ratio possibilities, little to no bleed, a generous injectability window, adjustable rheology and set time, impressive strength, volume stability, extremely low hydraulic conductivity, negligible contraction cracking from heat of hydration, self-healing ability, resistance to chemical attack. And then these things too: a ready-to-mix-and-pump product, custom blend options, a stable and competitively-priced supply, rigorous quality controls that insure consistent performance, expert and experienced technical support, an international distribution network, and a safe-to-use, non-hazardous product. US Grout Ultrafine grout delivers all of that.
Custom Fit Grout for Specific Soils
Designed for job-specific flexibility, US Grout type VX, paired with our USG-Super (a super p), can work its effective magic in a wide range of soil permeation and stabilization projects. And to help project engineers quickly dial into the grout-plasticizer-soil standard for each project, US Grout provides a testing service that utilizes project-specific soil samples. The returned starting point means less guesswork and quicker completion times.
Typical Applications for Cementitious Grouts for Soil Stabilization, Groundwater Control, and Soil Strengthening Applications
LARGE-SCALE CIVIL PROJECTS
Cementitious grouts are used for a wide variety of civil-scale construction projects. To stabilize soil or control groundwater, these substantial constructs require a significant amount of grout, and cost efficiencies mean cementitious grouts are typically the first consideration.
Soil Stabilization—With the grand scope and significant costs embraced by large-scale civil undertakings, the condition of the soil around and beneath the project is a critical component that demands careful consideration. Improving the performance of the soil with injectable grouts is a common solution for a variety of geotechnical needs. In the case of levees, earthen dams, and in-place waste encapsulation, the soil itself serves as the structural media. In other projects, such as subway and mining tunnels, vertical shafts, below-ground structures, and waste and settlement ponds, injected grout serves to stabilize, strengthen, and curtain-off groundwater, rendering such projects viable in almost any soil type or soils-structure condition.
COMMERCIAL CONTRUCTION PROJECTS
No matter the size of a construction project, the cost of buying both in-soil performance and performance longevity matters. US Grout Ultrafine cementitious grouts are economical, permanent, environmentally low-impact, safe to use, and geologically effective in a wide range of soil types. [ CASE STUDY: Radisson Plaza Hotel ]
Junk and Indiscriminate Fills in Building Lots—Rather than removal and replacement—or even piling—it is often more economical to permeation grout poorly-infilled building sites to achieve the necessary stability and bearing capacity.
Settlement Control for Foundations and Pipelines—Bridges, building foundations, support piles, pipelines and cables, retaining walls...all are subject to failure if the soils supporting their massive weight shift. Cementitious grouts can be injected into the surrounding soils to prevent such problems. Such preventative measures are especially important in the presence of weak soil zones. [ CASE STUDY: Hill Auditorium ]
Sidewall and Slope Stabilization—Why de-water, lag, or sheet when you can stabilize the soil with grout? And the stabilization can be done anywhere from a few hours to a few months in advance of the project.
Stabilize Soil Movement for Excavation—When soils are soft and prone to collapse, low-strength cementitious grouts can be economically called upon to provide the necessary “support of excavation.”
Stabilize Soil for Tunnel Excavation—When cut-and-cover is not a viable option, a tunneling operation is necessary. If the tunnel passes beneath canals, pipelines, rail or road beds, stabilizing the soil beneath is absolutely critical. Ground stabilization grouting before driving the tunnel is a proven technique, providing stability and controlling water and erosion into the tunnel bore.
Protect Buried Utilities—Establish protective grout curtains around underground utilities to control settling and shifting problems resulting from soft soils or groundwater seepage.
Controlling Leachate when Rehabilitating Brownfield Sites—A permanent cementitious grout can be utilized to deny water infiltration and lock down the contaminated soils of a brownfield site. (For projects seeking LEED certification, there are points available for reclaiming a brownfield site)
Settling Ponds, Sewage Ponds, Waste Ponds—Tightening the soils around and beneath holding ponds will solve a host of exfiltration problems.
Cementitious Grouts are also used extensively to help stabilize and extend the life of deteriorating infrastructure. [MORE on XXXX]
Sanitary Sewer Systems—Seal against infiltration of groundwater from without and exfiltration of sewage into surrounding soil and groundwater.
Pipeline Flow—Reestablish support and bearing capacity of soil around stressed pipelines.
Levees—Improve flood control infrastructure by strengthening hold-back capacity and mitigating erosion forces that attack levees. Mitigate destructive seepage by injecting a wall of cementitious grout directly into the core of the levee.
Earthen Dams—Seal against water seepage at the structure’s base with a cementitious grout curtain.
Foundations and Support Footers—Strengthen and/or fix in place surrounding soils to stabilize movement and add bearing capacity.
Catch Basins—Contain runoff-borne contaminants.
Squeeze Cement Oil and Gas Wells—Repair casing leaks, seal lost-circulation zones, remedy deficient primary cements, shut-off breakthrough points.
Erosion Control—A strong cementitious grout binding with erosion-prone soils will help hold it in place.
Seepage Cutoff Walls through Complicated Encroachments—When obstructions exist above and below ground that prevent the construction of traditional seepage cutoff walls, a cementitious grout curtain can be precisely injected around these complicated encroachments—bridges, power lines, pipelines, rail lines, roads, and various utilities.
Seepage Cutoff Barriers for Canals—Both seepage control and embankment stability are the benefits of injecting a strong cementitious grout to form curtain zones along canal ways. Even problems resulting from mixed and random embankment materials can be successfully grouted.
Sink Holes and Voids—Whether the cause is naturally-occurring or caused by improper construction practices or broken utility lines, below-grade or -structure voids are best handled by pumpable cementitious grouts. Not only are the existing voids filled, but the grout pushes into weak areas, compacting and strengthening the soil. The grout also establishes a protective cap and curtain to prevent further destabilization.
Conventional Grouting Practices, Unconventional Grout
Rest easy. US Grout products were formulated for tough grouting situations, but designed to be placed by conventional grout practices and equipment. Our grouts offer a generous two-plus hour injectability window, are simple to properly mix, and are safe to use.
US Grout products are sourced and made in America, are available via an international distribution network, and backed by many years of practical grouting experience.
As the world-wide distributor for US Grout products, Avanti International (www.avantigrout.com • 1-800-877-2570) provides the customer service, objective professional advice, material estimates, and the caliber of world-class technical support that comes only from over 35 years of geotechnical experience.