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Testing Specifications

Prior to road construction, the following three soil analyses should be completed. Soils within the design specifications below will generally show the greatest potential for Enzyme stabilization. Additionally, use of proper Enzyme Road application procedures is critical to ensuring maximum stabilization and road performance.

Gradation Test method: ASTM E-11, D-422 or similar gradation analysis. Enzyme catalyzes stabilizing reactions with cohesive (plastic) fines in the soil. Construction material should be comprised of at least 15%, but no more than 65% fines passing the #200 screen with at least 6% cohesive clay preferred.  

Plasticity Test Method: ASTM D-4318 (Atterberg Limits). The Liquid Limit (LL) should be less than 40% and the Plasticity Index (PI) between 5 to 20%.


PH Test Method: Per equipment manufacturer’s instructions. A soil PH of 4.5 - 9.5 is best. Low pH soils can be treated with calcium carbonate (lime). High PH soils can be treated with sodium sulfate, magnesium sulfate or muriatic acid. Enzyme concentrates have a PH of 3.2-5.1.

The following tests may also be used to estimate road performance and to adjust application rates.


Maximum Dry Density/Optimum Moisture Content (OMC) Test Method: ASTM D-1557 Modified Proctor (heavy hammer). Apply Enzyme rate 1 liter per 33 m3 of soil and. Enzyme treatment increases soil density and reduces OMC by 2%-4%.

California Bearing Ratio (CBR) Test Method: ASTM D-1883. This test measures resistance of soil to loading and can be used to show the increased resistance to loading from Enzyme treatment. Dry CBR tests best represent field conditions. When wet testing is required, treated samples must be covered and allowed to cure from 2 – 3 weeks before immersion in water.

DCP Resistance improvements of field trials should be tested at 4 weeks, 8 weeks and 14 weeks using Dynamic Cone Penetrometer or Clegg Impact equipment.


Permeability Test Method: ASTM D-5084. Reductions in moisture penetration due to treatment with Enzyme will favorably impact the performance and endurance of the road. Reductions in permeability of greater than 50 times are expected, as compared to untreated soils.


Field testing and actual road performance will most accurately demonstrate the benefits from Permazyme treatment.

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