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RE-Act 4TM


Re-Act 4 Logo

Opta Glass manufactures R-E-D’s Re-Act 4. Made from 100 percent recycled glass, Re-Act 4 is an amorphous glass powder with excellent pozzolanic properties.

An environmentally safe and sustainable secondary cementitious material, Re-Act 4 is suitable for countless applications in the refractory, mineral processing, and construction materials industries.

Make a sustainable choice for your next project.

RE-Act 4 is a high-performance ground-glass pozzolan used in construction products ranging from ultra-high-performance concrete to architectural pre-cast and from ready-mix concrete to premium durability grades. Added to cement, it makes the finished product more durable, long-lasting, and cost-effective.

Re-Act 4 contributes to the function and application of sustainability, improving the longevity and viability of your products.


Using RE-Act 4 in your concrete mixture will:

  • Increase 28-day strengths.

  • Provide a twenty-times reduction in CO2 emitted compared to ordinary Portland cement.

  • Improve chloride and sulfate resistance.

  • Moderate ASR resistance.

  • Improve freeze and thaw resistance.

  • Result in exceptional UHPC mixtures.

As a 100 percent recycled product, Opta and R-E-D’s Re-Act 4 reduces glass in landfills and lowers the overall carbon footprint.


Analysis Typical Min Max
SiO2 (%) 70.0 68.0 80
Fe2O3 (%) 0.5 0.1 1.0
Al2O3 (%) 1.0 0.3 5.0
CaO (%) 10.0 2.0 15.0
NaEq (%) 13.0 7 15.0
>45μ(%) 0.0 0.0 0.0
LOI 0.2 0 0.5
Pozzolanic Activity (%) 28d 107 100 125
Water Demand (%) 99 97 102
Brightness (L*) 94 90 97

*These values describe a mean range and do not represent a specification.