Compressive Strength Testing
After the recycled glass is processed down to the required fine size, it can now be used as a fly ash substitute in the concrete mix.
ACS’ initial testing has proved that you can achieve desired mix workability qualities and strength in concrete by using a 30% replacement of glass powder. At 28 days, our cylinders achieved their required strength.
Since standard mix designs typically have a 20-25% replacement using fly ash, this is a great benefit to further reduce the OPC (Ordinary Portland Cement) content while not diminishing compressive strength.
Reduced Chloride Permeability
Concrete containing 30% Type GS ground glass as a partial cement
replacement has less chloride permeability long-term than a slag or
fly ash mixture. Having this feature creates a more durable concrete.
ASR (alkali-silica reaction) is caused between the alkaline pore of concrete and a silica aggregate reaction. The silica structure around an aggregate is dissolved through reaction of OH- ions, which creates a gel-like structure that cross-links, coagulates and swells the concrete.
It has been proven that the finer glass powder as cement replacement actually mitigates ASR. At a 30% replacement using glass powder, our expansion percentage falls below the threshold required per ASTM and is improved compared with fly ash.