September 2000 – September 2001

Road Stabilization Report

Public Works Road - Blood Reserve

Standoff, Alberta

Canada

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GENERAL USE OF TERRAZYME SOIL STABILIZER IN ROAD CONSTRUCTION

1. INTRODUCTION

This work discusses the use of TerraZyme soil stabilizer and its application in the infrastructure of unsurfaced roads. It summarizes work on several sections of a road constructed on the Blood Tribal Reserve near Stand Off, AB Canada during late September of 2000. The purpose was to demonstrate the broad use of TerraZyme soil stabilizing technology, in the private Reserve sector, as in municipal and provincial projects, and to discuss results after one year.

TerraZyme is used world-wide in strengthening of base layers of unsurfaced roads or soil roads, in base layers and sub-base layers of highways covered with asphalt material, with recycled pavement, in surfaced and unsurfaced pavements of urban streets, shoulders of highways, restoration of pavement of irregular stones and on forest highways. Among the soil materials stabilized by TerraZyme are sandy clay, silty clay, sandy silt, plastic and non-plastic clay, sandy loam, fine loam, loam mixed with clay, soil mixtures with pieces of recycled pavement, among others.

2. CONCLUSIONS

After evaluation of this project using TerraZyme stabilization of soils, it was concluded that the stabilizer promotes the following benefits versus non-treated soils:

Increases in CBR% raised the capacity of the road surface to support greater light and heavy traffic loads; the average untreated subbase CBR is 20%. The TerraZyme treated sections averaged 117%, almost a six times increase in CBR load bearing capacity. This increase has greatly reduced the commonly seen problems of rutting, potholes and washboarding of the road.

As a result, only one (1) road grader repair was required on the stabilized road section during the past twelve months. This contrasts to historical biweekly road repair program during the seven-month repair period. The current road maintenance budget of about $1,000,000 CA per year will be dramatically reduced through wide usage of road stabilizers.

Helps the soil surface layer to conserve its structural integrity, under loading, without occurrence of serious defects, such as holes, surface deformation and valleys.

Minimizes the material loss of gravel from erosion or abrasion by the traffic on the soil roadways, preserving the original traverse section and slopes; and also reducing the ongoing cost of replacement gravel, its transport and spreading and source of vehicle accidents.

Impedes the widespread occurrence of dust from loose fine material in the surface of the soil roadways; which is becoming a health and cleanliness concern. Dust reductions of about 75% occur with stabilization of the road surface.

Reduces cost of purchasing and transporting of construction materials for road repairs and maintenance by upgrading and improving the poorer, local soils for local road use.

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It is recognized that successful treatment of local, available materials at the Reserve road sites will provide the economic solution to minimize the project maintenance cost, without depriving road function and durability. This work demonstrates that this new concept of stabilization of soils will provide important savings in the construction costs and maintenance costs of roads: rural, access, and farm unsurfaced roads.

3. BACKGROUND

A survey of current road conditions on the Blood Reserve reveals typical problems associated with roads constructed of river gravel and sand, including washboarding, material loss, loose surface gravel potholes and dust. These conditions degrade the utility of the road surface, increase maintenance costs and cause accidents through loss of a firm surface at higher speeds. Ruts and potholes can become severe during wet weather. (See Appendix A for dry weather photographs of existing, unstabilized Reserve roads)

Additionally, materials for roads that meet the necessary construction standards are becoming more expensive and scarce. Frequently, it is required to import materials from another areas resulting in great transport distances and consequent increases in the cost of the project. Often when lower quality materials are used in unsurfaced or soil highways, they exhibit unsatisfactory effects from vehicles loads or humidity conditions.

For many roadways, especially with low traffic volume, as rural, local and capillary roads or even high traffic highways, the local soil contains a high percentage of fines and a high plasticity index and do not have appropriate soil characteristics. However, if these soils can be upgraded by stabilization, they can be used successfully to supply material for bases and sub-bases.

The decreasing availability and growing cost of acquiring road construction materials is forcing engineers to consider more economically methods of building highways using locally available soil, although outside of specifications. The situation is more critical when the growing demand for roadways in underdeveloped and rural areas is considered. In addition, pressures in industries, such as mining, agriculture, forest, and others to minimize production costs, are requiring the construction of roads with suitable quality, but lower maintenance costs. Consider also the benefits to the environment of minimizing the harmful production and use of crushed aggregate and historical mineral stabilizers in road constructions. An economical solution is available to reach these objectives - the stabilization of soils with bio-enzymes. Appendix E provides more information.

4. MEASURMENT OF RESULTS

Information on the performance of the TerraZyme treated soil structural layers of the Blood Reserve roads came from measurements in the field with DCP (Dynamic Cone Penetrometer) equipment, after 10 months of road usage. The DCP equipment measures the resistance of penetration of a machined cone point into the soil bed from repeated drops of an 8 kg weight. The less the penetration in mm per drop (the less the slope), the greater will be the resistance and the firmness of the soil bed. These values correlate closely with the California Bearing Ratio (CBR%), a primary indicator of the load handling capability of the road to traffic loads. It is well known that road beds with higher CBR readings are

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less susceptible to pot hole and rut formation and aggregate and fine material loss. Therefore, less maintenance is needed. TerraZyme treatment increased the CBR% values, thus increasing durability of the road. Further, experience has confirmed reductions in dust levels of about 75% from stabilization by better securing the fine material on the road surface.

5. DEMONSTRATION ROAD STUDY

We will comment on the experimental road sections on the Blood Tribal Reserve undertaken in September 2000 and analyzed 10 months later in July 2001. These results will be the basis and justification of future, more extended road projects.

Public Works Road – Stand Off, AB

In late September of 2000, through a effort organized and supervised by Engineer Winslow Davis and Tribal road construction workers and equipment, a two segments of about 350 meters (South West Kanaka road) and about 350 meters of North road (in front of the PW building and Store) were stabilized. Conventional construction equipment was used (road grader with scarifying teeth, tractor pulled disk, water truck, a sheep’s foot and a steel drum roller). Application details are in Appendix B. About 8 kms of roads are now stabilized.

Soil Characteristics

The average characteristics of the material of the base treated with TerraZyme are approximately as see below. The soil shows decent gradation, some of which is a result of gravel added during historical maintenance. The fine material is quite plastic with an Index of Plasticity (IP) of nearly 19%. The CBR% values of the untreated road soil are about 20%.

% Passing Screen – Base Material

Atterberg Limits

2” 1” 3/8” No 4 No 10 No 40 No 200 LL LP IP

100 95 75 64 55 41 27 33.5 14.6 18.9

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CBR Improvement

The stabilized sections now have more than 300 days of traffic usage, with few surface defects. Some small depressions were noted. They seemed to be partially filled with loose aggregate. DCP measurements, taken of the stabilized soil, showed good soil stability and firmness. This suggests the cause of the depression to be inadequate mixing of the soil in that surface spot. Below the shallow deformities CBR values were consistent with other sections. Before the corner, between NW and N roads, a spot showed some surface deformation due to inadequate mixing of the additional clay that was added to build up the curve.

Elsewhere, good surface hardness was achieved and the efficiency of the enzymatic stabilizer action demonstrated. The monitoring of the CBR in the top 15 cm treated surface, with the dynamic cone penetrometer – DCP, showed an important increase in the load bearing capacity through stabilization. In Appendix D, Figure 1 shows the CBR values for the upper 15 cm of treated soil versus the untreated section below on the NW road section. In Appendix D, Figure 2 shows the CBR values for the treated soil versus the untreated section below on the North road section (in front of the Public Works Building and Store).

Note the dramatic difference in slope of the data seen on both Figures 1 and 2. The upper zone (about 15 cm of stabilization has considerably lesser slope/higher resistance values (CBR%) than the lower zone on both measured sections. In the region below the treatment the CBR% values are much less. This result is commonly seen through stabilization.

The standard value of CBR% = 100% is based on resistance of crushed stone to the DCP probe. Note that the average value of CBR = 176% for the North Road, is considerably more than a 15 cm bed of crushed stone. In many road projects, the practice of improving or upgrading the local soil through stabilization is used and crushed stone is replaced, with considerable saving in materials, transportation and therefore construction costs.

Reduction in Maintenance Cost

It has been common Reserve practice on light traffic loading roads to gravel annually and grade once per month. Heavier traffic loaded roads may require twice per month grading due to rut formation and other surface defects. This represents 16 gradings over eight months. The heavy traffic road sections that have been stabilized for ten months show no effects of the winter freeze thaw cycle, no washboarding, nor rutting nor potholes holes. Over the twelve month period from September 2000 to Sertember 2001, only one grading was needed; a 94% reduction in maintenance. Furthermore, dust levels have greatly reduced.

A higher quality road surface was achieved through the TerraZyme stabilization program. This reduction in maintenance work has freed up equipment for use on other roads. Actual maintenance cost savings will be calculated as the road stabilization is expanded to more kilometeres. Note in Appendix C the differences in road quality between existing, unstabilized roads (Appendix A).

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6. ACKNOWLEDGEMENTS

We thank the engineers and road teams of the Blood Reserve for all the information on the soils, field evaluations and for the given photos, without what we could not have turned this work informative and pleasant for the reader.

Especially our thanks to Chief Chris Shade, Chief of the Blood Tribe, Franklin Wells and Wayne Wells, Council Executive for their support in this work.

This Report was prepared by Winslow Davis, Blood Reserve Public Works Director, Standoff, Alberta Canada and Jon Sedgwick, TerraZyme Field Development Director, Nature Plus, Stratford, CT Nature Plus Enzyme Products, an ISO 9002 Certified Company, manufactures TerraZyme Soil Stabilizer in Stratford, CT 06615. (T) 203-380-0316 (F) 203-380-0358 www.terrazyme.com info@nature-plus.com September 2001

LOOSE GRAVEL RUT DEPRESSIONS – 20 cm

POTHOLES/EROSION DUST PROBLEMS

APPENDIX A. EXISTING, UNSTABILIZED BLOOD RESERVE ROAD CONDITIONS

APPENDIX B. TERRAZYME APPLICATION - STANDOFF, ALBERTA

Removal of loose gravel Scarifying of road surface

Spreading of loosened soil

Application of TerraZyme Uniform mixing Compaction

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APPENDIX C. VIEWS OF STABILIZED BLOOD RESERVE ROADS AFTER ONE YEAR

Improved Surface

Reduction in Dust

Reduction in Maintenance Costs

Strengthened Load Bearing Capacity

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FIGURE 1

APPENDIX D. ROAD STRENGTH INCREASES WITH STABILIZATION

Blood Tribe Public Works Road DCP at 10 Months (South West Road Section)

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SW Road 1

SW Road 2

TerraZyme Stabilized Zone Average CBR = 62%

Unstabilized Subgrade Average CBR = 16%

FIGURE 1

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FIGURE 1

Blood Tribe Public Works Road DCP at 10 Months (North Road Section)

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North Road-East Lane

North Road-West Lane

TerraZyme Stabilized Zone Average CBR = 176%

Unstabilized Subgrade Average CBR = 23%

FIGURE 2

APPENDIX E.

Bio-Enzymes

TerraZyme is a bio-enzyme product, a chemical, organic, and liquid concentrated substance, used with increasing frequency to improve the stability of aggregates and soil materials in the roadways and other pavement structures. In other parts of the world, these materials are providing great economic benefits. In Canada, they are only now being used for rural and secondary road projects in private sectors, but they have applications in municipal and provincial projects. It is foreseen that in the near future, in order to not become static and inattentive to progress seen elsewhere, the Province of Alberta and the National Department of Highways of Roads will begin to establish standards through research and extensive observations in field, for these proprietary soil products.

This concentrated stabilizer liquid are specifically formulated to modify the engineering properties of soils and aggregates; it requires dilution in water before the application to allow for the product to be dispersed and uniformly mixed with the particles of soil material being treated. The dosage levels of the stabilizer concentrates vary from 1 liter up to 2 liters for 35 m3 of soil, depending on the soil type and soil characteristics. The amount of dilution water depends on soil dryness. In the field, measurements are made to determine the difference between the actual field soil moisture content % and the optimum moisture content % for maximum compaction. This calculated amount of water brings soil up to optimum moisture content. In cases where the soil material contains high amounts of fines or high plasticity, the water added is often from 1 to 2% below optimum moisture.

In countries that are using bio-enzyme stabilizers, in general the usage costs are much lower than conventional chemical stabilizers. This is because there initial price is lower, the application is simpler and less expensive and transport is cheaper. In these countries economic factors continue to open new application areas. Even when modest increments in the road stability occur, there is an increase cost-effectiveness and improvement in performance and durability of the roadways. Government studies in the country of Malaysia have documented results showing over 75% reduction in maintenance over a three-year period on TerraZyme treated secondary roads.

The verification that TerraZyme soil stabilizer can provide significant improvements in the properties of the treated materials is a requirement for road engineers and researchers, who have not had previous field observation, experience and analysis of this technology.

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APPENDIX F.

Application Details

The Public Works road was divided at the bend adjacent to the Public Works yard entrance, with 350 meters of road on each side of the division. Beginning with the west entrance to the Public Works road, six cm of crushed gravel (one-inch minus) was placed on 350 meters of road 11 meters wide and the road was scarified to a depth of 25 cm. 48 liters of TerraZyme 11X (1 liter per 25 m3 of soil) were mixed into about 38,000 liters of water and mixed into the road material using two graders. Initial compaction was with a 10-ton split-wheel sheepsfoot roller pulled by a four-wheel drive tractor. Final compaction was by a 10-ton smooth drum roller using vibratory and static passes. About 60 cm of clay fill was placed at the bend to smooth the curve and help cars stay on the road in winter driving conditions. The fill was placed in 20 cm lifts, treated with TerraZyme and compacted using the sheepsfoot roller. Following the completion of the fill operation, crushed gravel was placed and the top 25 cm was treated as part of the initial 350-meter section. Beginning from the fill location at the bend, the second 350 m section was further divided into two lanes of 6 meters width. Six cm of crushed gravel (one-inch minus) was placed on the surface and the each lane was treated separately to a depth of 15 cm. Scarification using an agricultural disk was not effective to full depth. A steep blade angle (side to side) was then used very effectively to furrow each lane to the full depth necessary to bring up a quantity of the underlying clay. This was mixed with the existing road material (contaminated gravel) and the crushed gravel placed on each lane. 13.4 liters of TerraZyme 11X for the east lane and 12.0 liters for the west lane (1 liter per 33 m3 of soil in each) were each blended with about 10,000 liters of water. Mixing was by grader and disk plow and two passes with the compactor were completed the same night. Compaction by smooth drum roller was completed the following morning (29th) with vibration used in the initial passes.