BIO-ENZYME STABILIZED LATERITIC AND SHEDI SOILSThesis Submitted in partial fulfillment of the requirements for the degree of MASTER OF TECHNOLOGY in TRANSPORTATION SYSTEMS ENGINEERING by GANESHA CHATRADA (07TS06F)

DEPARTMENT OF CIVIL ENGINEERING NATIONAL INSTITUTE OF TECHNOLOGY KARNATAKA SURATHKAL, MANGALORE -575 025 JULY, 2009

BIOENZYME STABILIZED LATERITIC AND SHEDI SOILSThesis submitted in partial fulfillment of the requirements for the degree of

MASTER OF TECHNOLOGY in TRANSPORTATION SYSTEMS ENGINEERINGby GANESHA CHATRADA (07TS06F)

DEPARTMENT OF CIVIL ENGINEERING NATIONAL INSTITUTE OF TECHNOLOGY KARNATAKA SURATHKAL, MANGALORE-575 025 July, 2009

DECLARATION

I hereby declare that the report of the Post Graduate Project Work entitled BIOENZYME STABILIZED LATERITIC AND SHEDI SOILS which is being submitted to The National Institute of Technology Karnataka, Surathkal in partial fulfillment of the requirements for the award of the Degree of Master of Technology in Transportation Systems Engineering in the Department of Civil Engineering, is a bonafide report of the work carried out by me. The material contained in this report has not been submitted to any University or Institution for the award of any Degree.

07TS06F, GANESHA CHATRADA -----------------------------------------------------------------------------Department of Civil Engineering

Place: NITK, SURATHKAL Date: June 2009

CERTIFICATE

This is to certify that the P.G. Project Work Report entitled BIOENZYME STABILIZED LATERITIC AND SHEDI SOILS submitted by GANESHA CHATRADA, (Registration Number: O7TS06F), as the record of the work carried out by him, is accepted as the P.G. Project Work Report submission in partial fulfillment of the requirements for the award of the degree of Master of Technology in Transportation Systems Engineering in the Department of Civil Engineering.

Dr. A.U.Ravi Shankar Professor Department of Civil Engineering NITK, Surathkal

Chairman- DPGC

ACKNOWLEDGEMENTI would like to express my sincere thanks and gratitude to my esteemed guide Dr. A. U. Ravi Shankar, Professor, Department of Civil Engineering, for his guidance, valuable suggestions, continuous encouragement and the facilities extended during the course of my thesis work. I am extremely thankful to Dr. N. Bhavanishankar Rao, Professor and Mr. I. Ramesh Mithanthaya Research Associate, Department of Civil Engineering for their help, valuable suggestions and guidance throughout my thesis work. I acknowledge my sincere gratitude to Dr. M.C. Narasimhan, Professor and Head of the Department of Civil Engineering for his guidance, for his suggestions and cooperation during my thesis work. I express my thanks to geotechnical laboratory staff Sri. Sadanand Kadri for his cooperation and providing the necessary assistance during the experimental investigation of this project work. I am thankful to all my friends and classmates for their help and support throughout my stay in this college. I am greatly indebted to my parents who are responsible for successful completion of my M.Tech course. At the end I thank one and all who have supported me directly or indirectly.

GANESHA.CHATRADA

DEDICATED MY FAMILY AND FRIENDS

ABSTRACTEngineers are responsible for selecting or specifying the correct stabilizing method, technique, and quantity of material required. Soils vary throughout the world and the engineering properties of soils are equally variable. The key to success in soil stabilization is soil testing. The method of soil stabilization selected should be verified in the laboratory before construction and preferably before specifying or ordering materials. Various techniques are being used for stabilization of soil. Stabilization of soil with BioEnzyme is a very new method to improve the geotechnical properties of the soil. The Bio-Enzyme when added to water and mixed with soil alters the engineering properties depending upon the type of the soil and dosage of enzyme. These enzymes are liquid additives, which act on the soil to reduce the voids between soil particles and minimize absorbed water in the soil for maximum compaction. The enzymes react with the organic matter (humid matter) in the soil to form cementatious material. This reaction commences almost immediately and it is verified that under the right environmental conditions about 90% of the reaction may be complete within the first 96 hours. Initial reaction product is a formation of a gel, which crystallizes to form bonds, which hold together particles. Loss of moisture by evaporation is essential for the crystallization of gels. The reaction is at micron level and the presence of finely divided humid matter and clay-sized particles is essential. Presence of clay is essential as the bonds formed bind this size of particles. In this present study, the effectiveness of bio enzyme in stabilizing the different types of soils of Udupi and South Kanara districts are investigated through laboratory experiments as well as field study. The locally available lateritic and shedi soils are procured from the field is used for the investigation. Bio-Enzyme namely TerraZyme has been used as stabilizer. The pavements in Udupi and Dakshina kannada districts are damaged due to improper drainage system and Heavy rainfall (>3000 mm) added problems (about 6 month in a year) and another reason is the failure of the sub base due to improper material usage. The type of soils available in this region are Lateritic and shedi. The plasticity index is much more due to the high percentage of silt and clay content in these types of soil. In

this study, lateritic and shedi soil samples were collected from various sites to investigate the geotechnical properties. All the soil samples were tested for geotechnical properties and treated with variable enzyme dosages. The strength parameter of the stabilized soil has been evaluated after for a curing periods of 0, 1,2,3,4, and 8 weeks. The tests were carried out to determine the consistency limits, unconfined compressive strength and CBR. Since the CBR tests results on Bio-Enzyme treated soil indicate insignificant results and hence fatigue behavior of soil has been examined. These tests have been conducted with different curing period and with different dosages of enzyme. The laboratory tests have shown much improvement in its fatigue behavior. To verify the laboratory results, field study has been done by construction a stretch of flexible pavement with enzyme stabilized soil as sub base. Its long term effect on CBR strength is also evaluated by conducting the field test at regular interval after the road is open to the traffic. The field results have shown promising results in terms of strength of the stabilized soil. The road stabilized with Bio-Enzyme after one year clearly indicates the effectiveness of Bio-Enzyme as a stabilizing agent. Justify the use of enzyme as a stabilizer to stabilize the sub base soil in the road construction, analysis has been done by KENPAVE software. Keywords: Fatigue, TerraZyme, Stress level and KENPAVE.

CONTENTS

CERTIFICATE ACKNOWLEDGEMENT ABSTRACT CONTENTS LIST OF TABLES LIST OF FIGURES 11.0 1.1 1.2 1.3 1.4 1.5

i v vi 1-51 2 2 4 4 4

INTRODUCTIONGENERAL BRIEF HISTORY OF THE AREA UNDER INVESTIGATION USE OF ENZYME STABILISATION OBJECTIVES OF THE STUDY SCOPE OF THE WORK ORGANIZATION OF THE THESIS

22.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.7.1 2.7.2

LITERATURE REVIEWSOIL STABILIZATION APPLICATIONS OF SOIL STABILIZATION STABILIZATION OF LATERITIC SOILS TYPES OF STABILIZATION TECHNIQUES BIO-ENZYMES AS SOIL STABILIZERS IN ROAD CONSTRUCTION T THE ENZYMES CHEMICAL STRENGTHENING FUNCTION MECHANISM OF SOIL STABILIZATION BY BIO-ENZYME TERRAZYME, A BIO-ENZYMATIC SOIL STABILIZER TerraZyme uses for construction Features of TerraZyme

6-246 6 6 7 7 9 10 11 11 11

i

2.7.3 2.8 2.9 2.10 2.11 2.12 2.13 2.14 2.15 2.16 2.17

Environmental benefits of TerraZyme TYPES OF SOIL AND TERRAZYME EFFECTS COST SAVING FEATURE OF TERRAZYME WORKING MECHANISM OF TERRAZYME FAILURES IN SUBBASE LITERATURE REVIEW ON USE OF BIO-ENZYMES IN SOIL STABILIZATION GENERAL CONCLUSIONS ON THE BEHAVIOR OF TERRAZYME STABILIZED SOILS UNDER STATIC LOADING BEHAVIOUR OF SOILS UNDER REPEATED LOADING GENERAL CONCLUSIONS FOR SOILS UNDER REPEATED LOADING CONSTRUCTION METHODOLOGY TERRAZYME ON INDIAN ROADS

12 12 12 13 14 15 18 18 21 22 24 25-35 25 25 25 25 26 29 30 30 31 33 35

33.0 3.1 3.2 3.2.1 3.2.2 3.3 3.4 3.5 3.6 3.7 3.8

METHODOLOGY AND EXPERIMENTAL INVESTIGATIONSGENERAL DOSAGE OF ENZYME TESTING PROGRAMME Testing Programme for Basic Properties Testing Programme for Fatigue Experiments GRAIN SIZE ANALYSIS TEST ATTERBERGS LIMIT COMPACTION TEST UNCONFINED COMPRESSION TEST CALIFORNIA BEARING RATIO TEST PERMEABILITY TEST

44.0 4.1

FATIGUE ANALYSIS OF LATERITC AND SHEDI SOILSINTRODUCTION LABORATORY FATIGUE TESTING ii

36-5236 36

4.2 4.3 4.4 4.5 4.6

EFFECT OF ENZYME ON FATIGUE CHARACTERISTICS OF STABILIZED SOILS EFFECT OF ENZYME CONTENT ON FATIGUE LIFE EFFECT OF CURING PERIOD ON FATIGUE LIFE EFFECT OF LOADING AMPLITUDE (STRESS LEVEL) ON THE FATIGUE LIFE CORRELATION BETWEEN FATIGUE LIFE AND UNCONFINED COMPRESSIVE STRENGTH

38 40 44 47 51

55.0 5.1 5.2 5.3

PAVEMENT ANALYSIS AND DESIGNGENERAL KENPAVE - SOFTWARE PAVEMENT DESIGN USING -IRC 37-2001 ANALYSIS OF PAVEMENT SECTION

53-5853 53 53 54

66.0 6.0.1 6.0.2 6.1 6.1.1 6.1.1.1 6.1.1.2 6.1.2 6.1.2.1 6.1.2.2 6.1.3 6.1.3.1 6.1.3.2

ANALYSIS OF TEST RESULTS AND DISCUSSIONSGENERAL Lateritic Soil Shedi soil TESTS ON ENZYME TREATED SOIL

59-6359 59 59 60

Effect on Consistency Limits of Enzyme Treated Lateritic and Shedi 60 soils Effect of Enzyme on Lateritic Soil Effect of Enzyme on Shedi soil 60 60

Effect on Heavy Compaction of Enzyme Treated Lateritic and Shedi 61 soils Effect of Enzyme on Lateritic Soil Effect of Enzyme on Shedi soil Effect on Unconfined compression test results of Enzyme Treated Lateritic and Shedi soils Effect of Enzyme on Lateritic Soil Effect of Enzyme on Shedi soil 61 61 61 61 62

iii

6.1.4 6.1.4.1 6.1.4.2 6.1.5 6.1.6

Effect on CBR results of Enzyme Treated Lateritic and Shedi soils Effect of Enzyme on Lateritic Soil Effect of Enzyme on Shedi Soil Effect on Permeability of Enzyme Treated Lateritic and Shedi soils Effect on Fatigue life of Enzyme Treated Lateritic and Shedi soils

62 62 62 63 63

77.0 7.1 7.2 7.3

FIELD STUDYGENERAL DETAILS OF THE SITE FIELD PREPARATION AND CONSTRUCTION LONG TERM EFFECT OF ENZYME ON SOIL

64-6764 64 64 66

88.0 8.1

CONCLUSIONSCONCLUSIONS FUTURE SCOPE

68-6968 69

REFERENCES PHOTOGRAPHS BIO-DATA

70-72 73-75 76

iv

LIST OF TABLES Table No3.1 3.2 3.3

Title

Page No26 26 27 28 30 31 31 32 32 34 35 39 51 52 54 55 56 57

Testing Programme for Basic Properties Testing Programme for Fatigue Performance Properties of terrazyme

3.4 Ge Geotechnical properties of Laterite and Shedi soil 3.5 Liquid limit, Plastic limit& Plasticity index 3.6 3.7 3.8 3.9 3.10 3.11 4.1 4.2 4.3 5.1 5.2 5.3 5.4 7.1 7.2 7.3 IS Light Compaction Results IS Heavy Compaction Results Unconfined Compression values for Lateritic Soil Unconfined Compression values for Shedi soil Unsoaked and Soaked CBR test results Permeability Test Results Fatigue life of untreated soil specimens at different stress levels Correlation equations for Lateritic soil Correlation equations for Shedi soil Thickness of the layers for the initial stage in analysis (for subgrade soil CBR 2%, dual-tandem) Thickness of the layers for the final stage in analysis (for stabilized Base, dual-tandem) Stress Values at response points 1 and 13 for virgin base Stress Values at response points 1 and 13 for stabilized base

Index properties of the soil at the site before the application of Enzyme 65 Results of Dynamic Cone Penetration Test conducted after enzyme treatment Field CBR Values 65 66

v

LIST OF FIGURES Fig No.3.1 3.2 3.3 3.4 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 5.1 5.2 5.3 5.4 5.5 7.1

ContentsGrain size Analysis Graph for Lateritic and Shedi soil. Variation of Unconfined Compression Test Results with Different Enzyme Dosages & Different Curing Period for LS and SS

Page No.29 33 34 35 37 41 43 45 47 48 50 51 52 55 56 57 58 58 67

Variation of CBR Results with 4% Enzyme Dosages & for Different Curing Period LS Variation of CBR Results with 2% Enzyme Dosages & for Different Curing Period SS Schematic Diagram of Accelerated Fatigue Load Test Set-up Effect of Enzyme content on Fatigue life of Enzyme treated Lateritic soil specimen at different stress level and 2Hz Frequency Effect of Enzyme content on Fatigue life of Enzyme treated Shedi soil specimen at different stress level and 2Hz Frequency Effect of Curing period on Fatigue life for different percentage of Enzyme treated Lateritic soil Effect of Curing period on Fatigue life for different percentage of Enzyme treated Shedi soil Effect of stress level on Fatigue life of for different percentage of Enzyme treated Lateritic soil Effect of stress level on Fatigue life of for different percentage of Enzyme treated Shedi soil Correlation between fatigue life and UCC for Lateritic soil Correlation between fatigue life and UCC for Shedi soil Plan of the dual-tandem indicating the response points Plan and Cross-section of pavement for virgin base Plan and cross section of pavement for stabilized base Stress variation at response point 1 Stress variation at response point 13 Correlation between DCP readings to CBR values

vi

CHAPTER 1 INTRODUCTION1.0 GENERALEngineers are often faced with the problem of constructing facilities on or with soils, which do not possess sufficient strength to support the loads imposed upon them either during construction or during the service life of the structure. Many areas of India consist of soils with high silt contents, low strengths and minimal bearing capacity. These negative soil performance characteristics are generally attributed to the nature and quantity of the fines present in the material. For better performance of structures built on such soils, the performance characteristics of such soils need to be improved. The poor engineering performance of such soils has forced Engineers to attempt to improve the engineering properties of poor quality soils. There are various methods that could be used to improve the performance of poor quality soils. These methods range from replacing with a good quality soil to methods that involve complex chemical process. The choice of a particular method depends mainly on the type of soil to be improved, its characteristics and the type and degree of improvement desired in a particular application. Recently bio-enzymes have emerged as a new chemical for soil stabilization. Bio-enzymes are chemical, organic, and liquid concentrated substances which are used to improve the stability of soil subgrade for pavement structures. Bio-Enzyme is convenient to use, safe, effective and dramatically improves road quality. Stabilization of soils is an effective method for improving the properties of soil and pavement system performance. The objectives of any stabilization technique used are to increase the strength and stiffness of soil, improve workability and constructability of the soil and reduce the Plasticity Index. For any given soil many stabilization methods, using different stabilizing agents, may be effective to improve the soil properties in-place rather than removing and replacing the material. Availability or financial considerations may be the determining factor on which a stabilizing agent is selected.

1

1.1 BRIEF HISTORY OF THE AREA UNDER INVESTIGATIONDakshina Kannada is one of the districts of Karnataka, lying between the Arabian Sea on the west and Western Ghats on the east (12 27' -13 58' north latitude and 74 34' - 74 40' east longitude). The total area of the district is about 8,436 sq.km. The land under cultivation is only about 2000 sq.km. Dakshina Kannada has a forest area of about 4600 sq.km yielding a variety of timber. Annual rainfall ranges from 2000 to 4000 mm, mean temperature ranges from 850 F to 900 F with relative humidity of about 85 to 90 percent. Lateritic soils: Lateritic soils have been found in this region because of high rainfall, high temperature and high humidity with alternate wet and dry period, which is an ideal condition for laterisation. Nearly 40 percent of the soils are laterites. The colour ranges from red to yellowish red. The depth of this soil varies from 30 cm to 150 cm. The laterites have been mostly originated from igneous rocks and are well drained, residual with the presence of excessive Fe and Al. These soils have defective grain size distribution, with high plasticity index. Shedi soils: Shedi soil is available at a depth of few meters from the ground surface. Interestingly, above this poor layer, laterite soil, which is having comparatively high strength, is present. Shedi soil is very problematic soil for engineering activity. Its strength is high in dry condition, where as, significant reduction of strength takes place when there is increase in moisture content. This type of soil can be found in almost all parts of Dakshina Kannada district. Due to rapid industrialization many industries, roads, railway lines and other structures are coming up. The ground profile is highly undulating in Dakshina Kannada district. Hence roads or railway cuttings are very common. The stability of slopes mainly depends on this shedi soil profile, because laterite can withstand relatively steeper slopes. As filling material also shedi soil poses problems.

1.2 USE OF ENZYME STABILIZATIONExtensive research has been conducted studying the application of traditional stabilization additives such as lime, cement and fly ash (Santoni et al. 2001). However, engineering research studying non-traditional stabilization additives such as enzymes are less documented. The U. S. army conducted soil stabilization by use of 2

additives as early as the 1940s (Fine and Remington 1972) in the construction of airfields for heavy bombers. The US Army conducted extensive research on soil stabilization for roads and airfields. Field Manual 5- 410 Chapter 9 (1997) is a detailed chapter on the design, analysis and application of soil stabilization techniques. Soil stabilization techniques for civilian uses are currently a common practice with applications for roads and foundation performance improvement. According to Andromalos et al. (2000) soil mixing was first developed in the United States in the 1950s (Liver et al. 1954). In the late 1960 and early 1970s the Swedish used a mixed in place lime stabilization process (Ryan et al. 1989). In their paper (Andromalos et. al. 2000) the authors presented the design, analysis and application procedures of soil mixing in liquefaction mitigation and various other geotechnical applications. Krizek, (1992) conducted a study to evaluate the benefits gained by incorporating base course material with either fiber reinforced soil cement or compactable recycled aggregate cement into pavement systems. In his paper the author presented the cost benefits analysis of soil stabilization and presented a design procedure for pavement base course improvements using his proposed techniques. Santoni et. al., (2001) conducted a laboratory experiment to evaluate the stabilization of silty-sand (SM) materials with traditional and nontraditional chemical or liquid stabilizers. Their research focused on the load bearing capacity as the basis of performance characterization. They tested four types of enzymes and found that none of the enzymes tested improved the unconfined compressive strength of the soil under the dry or wet conditions. Write-Fox and Macfarlane (1993) studied the stabilization performance of two types of enzyme stabilizers in addition to the performance of an asphalt emulsion and lime additive product. The stabilizers were tested on a highly plastic fat clay material and were based on the unconfined compressive strength test. Their results indicated that the undrained shear strengths of the enzyme products were 21% higher than the control specimens this suggested that the products in the concentrations used, added a stabilizing quality to the relatively dry specimens. When the specimens were immersed in distilled water, the enzyme products nearly or completely disintegrated by slaking. This indicated that the products tested may not offer waterproofing qualities, using the recommended dilutions.

3

1.3 OBJECTIVES OF THE STUDYBased on the detailed literature review, the objectives of the present work are (1) To evaluate the engineering properties and fatigue behavior of Bioenzyme stabilized soil. (2) Analysis the pavement by using these materials. (3) Evaluation of field performance.

1.4 SCOPE OF THE WORKTo fulfill the above objectives, laboratory experiments are performed on Lateritic and Shedi soils stabilized with enzyme. Laboratory Experiments are performed to evaluate the effectiveness of enzyme in stabilizing the soils. Doing so the strength aspect is considered. Various influencing parameters such as dosage of enzyme, Curing period are given due consideration in evaluating the effectiveness. Once the effectiveness of the enzyme in improving the strength characteristics are established, the optimum dosage of enzyme for maximum strength improvement is arrived at The performance of enzyme stabilized soils are tested for, repeated loading by considering different stress levels and frequency. The pavement analysis is carried out by using KENPAVE software. A pavement stretch is constructed to observe the performance of pavement.

1.5 ORGANIZATION OF THE THESISAfter the first introductory Chapter, detailed reviews of literature performed towards understanding the enzyme stabilization is presented in Chapter 2. Chapter 3 examines the performance of Bioenzyme stabilized soil under static loading condition. Two different soils with wide range of plasticity index, is used for the study. The properties such as Liquid limit, Plastic limit, Compaction characteristics, unconfined Compression strengths and the California bearing ratio test are determined for stabilized soil. The parameters such as dosage of enzyme, curing periods are studied. The main focus in this chapter is to ascertain the effectiveness of 4

enzyme and their effect on different types of soils. The parameters such as dosage of enzyme and curing period are selected for further study under fatigue loading condition. Chapter 4 deals with the studies made to understand the behavior of enzyme stabilized soil under fatigue loading. The results of the experiments conducted under monotonic loading conditions are used as a basis for these experiments under fatigue loading. All the fatigue loading experiments are conducted in an automated fatigue loading apparatus. An attempt has been made in this chapter to bring out the effect of different parameters on fatigue life and the deformation. Chapter 5 presents the design of pavement according to IRC-37 guidelines and it also covers the analysis of the pavement structure using KENPAVE software. Chapter 6 discusses the test results and analysis of the laboratory experiments carried out in this investigation. Chapter 7 to compare the results obtained in the laboratory and the field. Where 1.35 Km stretch of Bioenzyme stabilized soil is used. Chapter 8 presents the general conclusions and future scope of the thesis.

5

CHAPTER 2 LITERATURE REVIEW2.0 SOIL STABILIZATIONSoil stabilization is the process of improving the engineering properties of the soil and thus making it more stable. It is required when the soil available for construction is not suitable for the intended purpose. In its broadest sense, stabilization includes compaction, preconsolidation, drainage and many other such processes. However, the term stabilization is generally restricted to the strength properties. A cementing material or a chemical is added to a natural soil for the purpose of stabilization. The decreasing availability and increasing cost of construction materials and uncertain economic climates force engineers to consider more economical methods for building roads. An obvious solution is to use locally available materials. However, all too often, these materials fall outside of required specifications. This situation becomes even more critical when an increasing demand for roads in underdeveloped rural areas and informal settlements comes into play.

2.1APPLICATIONS OF SOIL STABILIZATIONThe process of soil stabilization is useful in the following applications, Reducing the permeability of soils Increasing the bearing capacity of foundation soils Increasing the shear strength of soils Improving the durability under adverse moisture and stress conditions Improving the natural soils for the construction of highways and airfields Controlling the grading of soils and aggregates in the construction of bases and Sub bases of the highway and airfields.

2.2 STABILIZATION OF LATERITIC SOILSThe main purpose of stabilization is to improve the soil strength, bearing capacity and durability under adverse moisture and stress conditions. Soil stabilization has been extensively used in the roads, airfields, earthen dams and embankments, in erosion 6

controls, etc. Likewise, there are increasing pressures on the mining, forestry and agricultural industries to minimize the production costs of their roads while delivering optimum performance and low maintenance costs. An economically feasible solution for achieving these objectives is the use of enzyme soil stabilization. Yoder (1959) has categorized the various types of stabilizers according to the properties imparted to the soil. The types of admixtures include cementing agents, modifiers, waterproofing, water retaining, and miscellaneous chemicals. The behavior of each of these admixtures differs vastly from the others, each has its particular use, and conversely, each has its own limitations.

2.3 TYPES OF STABILIZATION TECHNIQUESBroadly, soil stabilization takes the following forms. 1. Mechanical stabilization, whereby the stability of the soil is increased by blending the available soil with imported soil or aggregate, so as to obtain a desired particle-size distribution, and by compacting the mixture to a desired density. Compacting a soil at appropriate moisture content itself a form of mechanical stabilization. 2. Mixing or injecting additives such as lime, Cement, sodium silicate, calcium chloride, bituminous materials and resinous materials with or in the soil can increase stability of the soil. Chemicals stabilization is the general term implying the use of chemicals for bringing about stabilization.

2.4

BIO-ENZYMES AS CONSTRUCTION

SOIL

STABILIZERS

IN

ROAD

Bio-Road products are a basic fermented and formulator of soil treatment products that create enzyme stabilization of base and sub-base soils used in road construction. We have found from our extensive worldwide experience that enzyme stabilization is effective when the soil contains a sizable fine-grained component. Little if any improvement is achieved in clean sands or gravels. In a study of the performance of over 40 miles of road surfacing stabilized with enzymes, the US Federal Highway Administration found that the best performance was obtained with well graded aggregates mixed with higher clay contents (5% to 15%