Improve Performance

Geofortis' Product Development Laboratory is staffed with engineers and technicians who, over the past 6 years, have conducted thousands of test mixes with natural pozzolans and local customers’ cements and aggregates.  We have optimized our products and perfected our procedures to evaluate how our products perform with customers' local raw materials and cements.

Alkali-Silica Reaction (ASR) Mitigation

ASR is a swelling reaction that occurs over time in concrete between the highly alkaline cement paste and the reactive non-crystalline (amorphous) silica found in many common aggregates. This reaction causes expansion by the formation of a soluble and viscous gel.  This hygroscopic gel swells and exerts an expansive pressure inside the siliceous aggregate over time, causing spalling and loss of strength of the concrete, finally leading to its failure.

ASR can cause serious cracking in concrete, resulting in critical structural problems that can even force the demolition of a particular structure.

Geofortis Natural Pozzolans quickly and preferentially react with the cement alkalis without the formation of an expansive pressure, because siliceous minerals in fine particles convert to beneficial compounds that add strength and reduce permeability.

A successful ASR test indicates expansion less than 0.10% after 14 days.
Cracks in Cement Cause by Alkali-Silica ReactionCracks in Cement Cause by Alkali-Silica Reaction
Internal Expansion in Concrete Cause By Freezing and ThawingInternal Expansion in Concrete Cause By Freezing and Thawing

Freeze / Thaw Protection

When moisture in concrete repeatedly freezes and thaws, internal expansion due to the formation of ice can cause the concrete to fail over time.  Properly designed concrete in cold regions contains air-entraining admixtures that form billions of very small air bubbles within the concrete matrix.  If these bubbles are the proper size, in the right quantity, and have the proper spacing then they act as relief valves to the internal ice pressures.  The residual carbon in fly ash (reported as LOI) inhibits proper air matrix formation in concrete.  Geofortis’ natural pozzolans contain no carbon, which results in simpler and more consistent air-entraining properties in concrete.

Concrete Setting Times

The time until a concrete mix starts to solidify is called the initial set.  This time will vary with concrete ingredients and temperatures.  When concrete becomes “thumbprint hard” finishers can start to finish the concrete surface.  Replacing cement with fly ash typically delays this setting time and can increase labor costs and other problems, particularly in cold weather.  Although admixture products can retard or accelerate the setting times, they can add significant cost.  Geofortis’ pozzolan exhibits little to no retardation with normal replacement rates providing a significant advantage in cooler weather.