Cementitious Grout Solutions

UltrafineThe Pantheon in Rome

Unique among all cementitious grouts produced in the world today, US Grout's cementitious grouts are made with the same pumice-based pozzolan the Romans used over 2,000 years ago. As proven by the Pantheon and many ancient Roman structures standing strong after two millennia, US Grout’s patented pumice-pozzolan based cement provides unequaled longevity. Developed by the U.S. Department of Energy, aptly named US Grout produces Ultrafine Cementitious Grout products equal or superior to any ultrafine grout available in the marketplace.

A Superior Grout

All products are sourced, refined, and produced in the United States. US Grout's Ultrafine cements are solely supplied and supported by Avanti. US Grout products are the professional choice for those critical grouting applications where only a superior, high-performance grout will do.

  • US Grout products are ready to mix and pump without additional admixtures.
  • Customized blends are available.
  • Competitively priced; stable North American supply.
  • Stringent quality control and modern plant facilities ensure uniformity.
  • Expert technical support; international distribution network.
  • Ultrafine grout will penetrate smaller fractures and finer-grained soils.
  • Low internal cohesion means greater penetration and lower drilling costs.
  • Composed of non-hazardous materials.

Permeation Grouting

An extensive, large scale permeation test proved that US Grout Ultrafine can pass through, and completely grout, a silty sand with a hydraulic conductivity as low as 5 x 10-2 centimeters/second. The hydraulic conductivity of the grouted mass was reduced to 1 x 10-7 centimeters/second.

Particle Size Information

Particle size and internal cohesion, not viscosity, determine a grout’s ability to penetrate extremely small openings. Ninety percent of the particles in Ultrafine grout are smaller than 8 microns and average 3 microns.*

Grout Characteristics

Pozzolanic grouts are engineered for:

  • Wide range of water to cement ratios.
  • Little or no bleed at recommended water-to-grout ratios.
  • Two-plus hours of injectability.
  • Rheology and set time adjustable with various admixtures.
  • Enhanced strength and decreased permeability.
  • Volume stability, less than 0.1% linear shrinkage.
  • Water soluble lime and alkalinity are greatly reduced.
  • Extremely low hydraulic conductivity/permeability.
  • Brine tolerant; applications in and around salt water.
  • Resistance to chemical attack due to lower alkalinity and very low hydraulic conductivity.
  • A low heat of hydration resulting in higher resistance to thermal contraction cracking.

*These sizes were determined by the Micro Meretics Company, using their sedigraph.


The pozzolanic qualities of US Grout’s pumice-based cements are legendary. The Romans built an empire on pozzolanic (pumice) concrete structures that endure to this day – some 2,000 years later. Now, enhanced by state-of-the-art refining and injection processes, that same pozzolanic chemistry fortifies a high-performance grout that is superior in performance and effectiveness. Naturally.



Literature & Case Studies Specifications Animations & Videos

Products You May Need*in Cementitious Grout Solutions

  • Ultrafine SD (avg. 3 microns)

    Ultrafine Standard

    Composed of a finely ground mixture of Portland cement, pumice, and dispersant...

  • Ultrafine VX (avg. 3 microns)

    Ultrafine Standard

    Composed of a finely ground mixture of Portland cement, pumice, and dispersant...

  • USG Super

    Ultrafine Standard

    USG Super is a liquid or dry powder polycarboxylate-based superplasticizer...