Showing papers on "Soil stabilization published in 1970"

Safety factors and the probability distribution of soil strength

Abstract: For soils exhibiting both cohesive and frictional components of strength, the natural variabilities of the components are compared for soil in the undisturbed state and as compacted in earth dams. ...

Mechanisms of clay stabilization with inorganic acids and alkalis

Abstract: A series of mono- and di-valent cation hydroxides, and certain strong acids, were allowed to react with a two- and a three-layer clay mineral (kaolin and montmorillonite) under conditions simulating those for normal soil stabilization in field practice, i.e. mixed, remoulded, and moist-cured at a moisture content and density approximating optimum compaction conditions. The progress of reaction was followed over extended periods of time, up to two years. Changes in strength and volume were correlated with chemical and mineralogical changes in order to identify those bonding mechanisms which contribute to inorganic soil stabilization. For an additive level of 10% by weight dry clay basis (9.1% total dry solids basis) it was shown that several distinct stabilization mechanisms exist. One major mechanism is the surface coating of fabric units, and another the reinforcement of the soil by product formation in crevices, angularities, pore constrictions, and similar defects which influence the mechanical properties of the whole sample. The importance of these reactions to practical soil stabilization is thus demonstrated.

Properties and behaviour of foamed bitumen mixtures for road building

Abstract: Foamed bitumen is finding increased acceptance in Australia as a means of stabilizing and strengthening marginal quality pavement materials. The paper summarizes the basic requirements for satisfactory performance of road pavement materials, with particular reference to the special requirements for bitumen stabilized materials.

Hydraulic fills to support structural loads

Abstract: Data are compiled based upon a review of the literature, concerning the relative density, penetration resistance, compressibility and rate of consolidation Only hydraulic fills placed by sluicing through pipes are considered, and emphasis is upon performance under ordinary dead and live loads Fills are classified according to the nature of the borrow materials: (1) fairly clean sand, resulting in a reasonably uniform fill of moderate density; (2) silty or clayey sand, for inhomogeneous fill of large void ratio; (3) stiff cohesive soil, resulting in a skeleton of clay balls with a matrix of sand and clay; and (4) soft cohesive soil, resulting in a laminated normally consolidated clay The characteristics of each type of fill are illustrated by a case study The placement and engineering properties of the most desirable type of fill—that derived from a fairly clean sand—are considered in detail

Reactions in portland cement-clay mixtures

Abstract: THE REACTION OF PORTLAND CEMENT WITH SOILS IS STUDIED TO OBTAIN INFORMATION ON THE PRODUCTS OF THE SOIL-CEMENT REACTION, RATES OF REACTION, ALTERATION OF THE MORPHOLOGY OF SOIL PARTICLES BY REACTION WITH CEMENT, AND EFFECTS OF CEMENT TREATMENT ON STRENGTH GAIN THE REACTION OF TYPES I AND II PORTLAND CEMENT WITH EIGHT RELATIVELY PURE CLAYS AND OF TYPE I CEMENT WITH THREE VIRGINIA SOILS COMMONLY USED FOR SOIL-CEMENT IS ALSO STUDIED NORMAL (ROOM TEMPERATURE) AND ACCELERATED (ELEVATED TEMPERATURE) CURING PROCEDURES WERE USED THE RATES OF REACTION WERE MONITORED BY CHEMICAL ANALYSIS OF WATER AND HYDROCHLORIC ACID LEACHATES OF SPECIMENS CONTAINING 40 PERCENT CEMENT REACTION PRODUCTS AND ALTERATION OF PARTICLE MORPHOLOGY WERE MEASURED BY UNCONFINED COMPRESSIVE STRENGTH TESTS IT WAS FOUND THAT MONTMORILLONITE IN SOILS SUFFERED THE GREATEST DETERIORATION IN REACTIONS WITH CEMENT, KAOLINITE LESS, AND ILLITE LEAST QUARTZ NEITHER IMPEDED NOR ENHANCED THE CONSUMPTION OF CALCIUM HYDROXIDE KAOLINITIC AND ILLITIC SOILS APPEAR TO DEVELOP GREATER STRENGTHS THAN MONTMORILLONITIC SOILS /FHWA/

Behavior of stabilized soils under repeated loading: stresses and deflections in cement-stabilized pavements

Abstract: THE PURPOSE WAS TO INVESTIGATE THE APPLICABILITY OF AVAILABLE THEORIES FOR PREDICTING THE INDUCED STRESS AND DEFLECTION RESPONSE OF CEMENT-STABILIZED SOIL PAVEMENTS TO LOAD. THE STUDY WAS DIVIDED INTO THREE PHASES, VIZ., (1) FIELD REPEATED PLATE LOAD TESTING ON TWO TEST PAVEMENTS; (2) LABORATORY STUDY OF REPRESENTATIVE SPECIMENS, INCLUDING LABORATORY- COMPACTED AND UNDISTURBED SPECIMENS TAKEN FROM THE FIELD; (3) PREDICTION OF STRESSES AND DEFLECTIONS IN TEST PAVEMENTS USING AVAILABLE THEORIES IN CONJUNCTION WITH THE APPROPRIATE MEASURED VALUES OF MATERIAL PROPERTIES. TWO TEST PAVEMENTS, EACH 20 FT BY 20 FT IN PLAN AND 8-IN IN THICKNESS WERE CONSTRUCTED USING A CEMENT-STABILIZED SILTY SOIL OVER THE NATURAL CLAY SUBGRADE. PAVEMENT 1 CONTAINED THREE PERCENT CEMENT, AND PAVEMENT 2 CONTAINED SIX PERCENT CEMENT BY DRY WEIGHT OF SOIL. REPEATED PLATE LOAD TESTS WERE CONDUCTED USING A RANGE OF PLATE SIZES AND PRESSURES. MEASUREMENTS INCLUDED: (1) SURFACE DEFLECTION, (2) SUBGRADE DEFLECTION, (3) TENSILE RADIAL STRAIN AT THE BOTTOM OF THE CEMENT- STABILIZED SOIL LAYER, AND (4) VERTICAL COMPRESSIVE STRESS AT THE SURFACE OF THE SUBGRADE. BOTH REPEATED-LOAD TRIAXIAL COMPRESSION TESTS AND REPEATED FLEXURAL TESTS WERE CONDUCTED IN THE LABORATORY. THE VARIABLES STUDIED INCLUDED (1) APPLIED REPEATED DEVIATOR STRESS, (2) CONFINING PRESSURE, (3) CURING TIME, AND (4) COMPACTION DELAY. THE FIELD BEHAVIOR WAS ANALYZED USING BOTH N-LAYER ELASTIC THEORY AND THE FINITE ELEMENT METHOD. SOLUTIONS BY BOTH METHODS WERE OBTAINED USING A CDC 6400 DIGITAL COMPUTER. THE GOOD AGREEMENT OBTAINED BETWEEN MEASURED AND PREDICTED STRESSES AND DEFORMATIONS SUGGESTS THAT STRESSES AND DEFLECTIONS IN CEMENT-STABILIZED SOIL PAVEMENTS CAN BE PREDICTED SUCCESSFULLY USING ELASTIC LAYER THEORY AND FINITE ELEMENT ANALYSIS TOGETHER WITH MATERIAL PROPERTIES DETERMINED FROM LABORATORY REPEATED-LOAD TESTS ON UNDISTURBED SPECIMENS TAKEN FROM TEST PAVEMENTS. SUCH RESULTS INDICATE THAT IT MAY BE POSSIBLE TO DEVELOP A PROCEDURE FOR PAVEMENT THICKNESS DESIGN THAT LIMITS CRITICAL STRESSES AND STRAINS WITHIN A PAVEMENT TO ACCEPTABLE VALUES. /AUTHOR/

Recommendations for stabilization of illinois soils

Abstract: RECOMMENDATIONS CONCERNING THE FEASIBILITY OF STABILIZING ILLINOIS OILS AND MATERIALS FOR HIGHWAY USES WITH COMMON STABILIZING AGENTS (CEMENT, LIME, LIME-FLY ASH, BITUMEN, AND COMBINATIONS) ARE PRESENTED. PEDOLOGICAL SOIL MAPPING AND CLASSIFICATION CONCEPTS AND THE DISTRIBUTION AND NATURE OF SURFICIAL SOILS OF ILLINOIS ARE DISCUSSED. VARIOUS ASPECTS OF STABILIZATION TECHNOLOGY (OBJECTIVES OF STABILIZATION, TYPES, NATURE, AND TYPICAL CONTENT REQUIREMENTS OF STABILIZING AGENTS, AND CONSTRUCTION CONSIDERATIONS) ARE DISCUSSED AND PREVIOUSLY DEVELOPED STABILIZATION GUIDELINES AND CRITERIA ARE PRESENTED. THE PROCEDURE USED TO DEVELOP STABILIZER FEASIBILITY RATING FOR A SPECIFIC SOIL SERIES IS DESCRIBED. STABILIZATION RECOMMENDATIONS ARE PRESENTED IN A TABULAR FORM FOR THE MAJOR SOIL SERIES OCCURRING IN ILLINOIS. IN ALL, FEASIBILITY RATINGS ARE PRESENTED FOR 77 PERCENT, AREAWISE, OF THE SURFICIAL DEPOSITS OF ILLINOIS. /AUTHOR/

Lime grout penetration and associated moisture movements in soil

Abstract: THE USE OF LIME, PLACED OR INJECTED, FOR DEEP SOIL STABILIZATION HAS BEEN A MATTER OF SOME CONTROVERSY. TO PERMIT A RATIONAL ASSESSMENT OF THIS PROCESS FOR DESIGN PURPOSES, A SERIES OF FIELD EXPERIMENTS WAS MADE. THESE WERE PARTICULARLY CHOSEN TO DETERMINE WHETHER DIVERSE SOILS SUBJECT TO INTERMITTENT SEVERE DRYING AND OCCASIONAL FLOODING MIGHT BE STABILIZED BY A LIME GROUTING PROCESS, AND IF SO WHAT RATIONAL DESIGN PROCEDURES WOULD BE REQUIRED. THE RESULTS SHOW THAT FISSURING OF THE SOIL AND THE MOISTURE ASSOCIATED WITH THE GROUT ARE MAJOR PARAMETERS FOR PRACTICAL PURPOSES, AND THEIR IMPLICATIONS FOR PRACTICAL APPLICATION OF DRILL-LIME AND LIME GROUT INJECTION PROCESSES HAVE BEEN CRITICALLY EVALUATED. /TRRL/

Field studies on the pulverization of black cotton soil for the construction of stabilized soil road bases

Abstract: STABILIZATION OF BLACK COTTON SOIL WITH LIME HAS BEEN FOUND EFFECTIVE IN IMPROVING THE ENGINEERING PROPERTIES OF THE SOIL. CONSEQUENTLY, THIS HAS LED TO THE INCREASING USE OF LIME-STABILIZED BLACK COTTON SOIL IN SUBBASES OR BASES OF ROAD PAVEMENT. A PROPERLY PULVERIZED SOIL IS, HOWEVER, A PREREQUISITE FOR SUCCESSFUL STABILIZATION OF SOIL. THIS PAPER DESCRIBES A NUMBER OF METHODS THAT HAVE BEEN TRIED IN THE FIELD TO ACHIEVE AN ECONOMICAL AND EFFECTIVE PULVERIZATION METHOD. IT HAS BEEN SHOWN THAT AN ACCEPTABLE DEGREE OF PULVERIZATION CAN BE ATTAINED WHEN THE SOIL IS HANDLED MECHANICALLY AT A PARTICULAR MOISTURE RANGE BY USING AGRICULTURAL MACHINERY. /AUTHOR/

Phenomenon of aggregation in the stabilization of soils with cement

Abstract: THE PHYSICOCHEMICAL CHANGES CAUSED BY THE STABILIZATION OF A BLACK COTTON SOIL AND AN ALLUVIAL CLAY WITH PORTLAND CEMENT ARE DESCRIBED. WITH BOTH SOILS, THE ADDITION OF CEMENT CAUSES AN AGGREGATION OF CLAY FRACTIONS INTO COARSER PARTICLES. THE EXCHANGEABLE BASES OF CLAYS ARE ALSO AFFECTED BY THE ADDITION OF CEMENT. THERE IS AN INCREASE IN THE EXCHANGEABLE CALCIUM, AND THE SODIUM AND POTASSIUM IONS ARE COMPLETELY REPLACED BY CALCIUM IONS GENERALIZED BY THE HYDRATION OF THE CEMENT. THE AMOUNT OF ALKYL INCREASES WITH THE CEMENT CONCENTRATION AND EVEN WITH SMALL AMOUNTS OF CEMENT SOME OF THE FREE LIME LIBERATED REMAINS UNREACTED. IN TIME, HOWEVER, ALKYL DECREASES. THE POSSIBLE MECHANISM OF SOIL-CEMENT REACTIONS IS OUTLINED. /AUTHOR/

Stabilization of soil with lime

Abstract: Soil stabilization with lime is used to improve clayey subgrades and bases of secondary roads. The chemical and physical reactions triggered off by lime stabilization are investigated, and two criteria for quality control are proposed: (1) fineness and (2) percentage of useful lime, e.g., lime capable of physically and chemically reacting with the soil and giving rise to changes in the structure of the latter resulting in cementation. Variations in atterberg limits, CBR values, density, etc., resulting from the addition of lime are discussed, and details are given of the tests to be conducted for determining the proportioning of the mixtures. It is concluded that: (1) small percentages of lime (1.5 to 8%) increase the workability and strength of plastic soils, prevent variations in volume, and increase imperviousness; (2) curing methods have a marked influence on results; (3) lime stabilization is not suitable for soil containing organic matter. /TRRL/

Soil stabilization. effect of molding conditions on the effective stress-strength behavior of a stabilized clayey silt

Abstract: : The influence of molding water content, as-molded dry density, and delay time prior to compaction after mixing in of the molding water on the effective stress-strength behavior of a clayey silt stabilized with hydrated lime and portland cement is presented in this report. This investigation used the results of high pressure consolidated-undrained triaxial compression tests with pore water pressure measurements. (Author)

Drill-lime treatment of shallow railway subgrade failures in expansive clays

Abstract: This report deals with a method of stabilizing roadbed by applying hydrated lime to holes drilled in the subgrade which Southern Railway has been utilizing. With some 80 locations treated, the results after a few months were encouraging. While it is too soon to evaluate permanent results, it appears that the drill-lime application may offer relief to areas having the following combination of features: 1) Expansive clays responding to lime treatment; 2) Track areas having shallow ballast sections; and 3) Shallow subgrade failures.

Chemical soil treatment makes aggregate base unnecessary

Abstract: SUCCESSFUL CHEMICAL SOIL STABILIZATION PROCEDURES IN THE FRANKLIN COUNTY RIVERVIEW AREA NEAR PESCO, IN EASTERN WASHINGTON ARE OUTLINED. THE SOIL WAS A SANDY SILT, RUNNING HEAVILY TO SILT. SCARIFICATION AND WINDROWING OF EXISTING STREET SOIL WAS THE FIRST STEP IN THE STABILIZATION. THE MATERIAL WAS WINDROWED AND LAID OUT AS WITH OTHER FORMS OF ROAD MIX. THE CHEMICAL SOLUTION WAS SPRAYED ON, AND THEN THE LOOSE SOIL BLADED INTO TWO EQUAL WINDROWS. THE MATERIAL WAS WATERED AND ROLLED UNTIL IT WAS SATURATED. WHEN THE MATERIAL WAS LAID OUT AND BLADED EVENLY, IT STARTED TO SET. IT WAS THEN ROLLED TO SECURE FULL COMPACTION. FOR SUCCESSFUL CHEMICAL STABILIZATION, IT IS SUGGESTED THAT THE CHEMICAL MUST BE AN AGENT THAT, WHEN ADDED TO WATER AND APPLIED TO A BASE OR GRANULAR SOIL, WILL REDUCE THE ORGANIC COMPOUNDS WITHIN THE SOIL THROUGH SPPEDED OXIDATION REDUCTION. IT SHOULD IMPROVE THE CHARACTERISTICS OF CLAYS AND SILTS BY LESSENING THE MOISTURE PRESENT AFTER PERIODS OF SATURATION. THIS CHEMICAL STABILIZATION PROCESS CAN BE USED FOR HIGHLY ORGANIC SOILS, CLAYS AND SILTS, ALKALINE CLAYS AND SILTS WHERE LIME AND CEMENT PROCESSES DO NOT WORK, CALICHE, SHELL OR OTHER LIME SOURCE SOILS. IT OFFERS A METHOD OF DISPERSAL OF NEW ASPHALT IN GRANULAR SOILS, OR OLD CURED ASPHALT, BETTER THAN MECHANICAL, BREAKING CRUSHING, OR PULVERIZING METHODS.

Durability and strength characteristics of lime-flyash-soil mixtures for road construction

Abstract: THE OBJECT IS TO ASSESS THE SUITABILITY OF LOCALLY AVAILABLE SOILS FOR STABILIZATION WITH LIME AND FLYASH. SUITABLE PROPORTIONING OF LIME: FLYASH: SOIL IS DETERMINED ON THE BASIS OF THE UNCONFINED COMPRESSIVE STRENGTH OF THE TEST SPECIMENS. THE PERFORMANCE OF THESE MIXES UNDER THE ADVERSE WEATHERING CONDITIONS, SUCH AS IMMERSION IN WATER AND FREEZING-THAWING HAS BEEN STUDIED BY LABORATORY TESTS. TWO TEST PAVEMENTS HAVE BEEN LAID IN THE FIELD WITH SELECTED LIME: FLYASH: SOIL PROPORTIONS. FIELD CBR AND PLATE BEARING TESTS, BOTH REPETITIVE AND NON-REPETITIVE, HAVE BEEN CONDUCTED ON THESE PAVEMENTS. THE PAVEMENTS HAVE EXHIBITED SEMI-RIGID CHARACTERISTICS AND CONSIDERABLE IMPROVEMENT IN LOAD CARRYING CAPACITY. /AUTHOR/

Concepts for developing stabilization recommendations for the soils of an area

Abstract: THE PERTINENT ASPECTS ARE PRESENTED OF A RESEARCH PROJECT AIMED AT DEVELOPING STABILIZATION RECOMMENDATIONS FOR THE SURFICIAL SOILS OF ILLINOIS. THE INVESTIGATION WAS CONCERNED WITH MAXIMUM UTILIZATION OF LOCAL AND ONSITE MATERIALS IN PAVEMENT CONSTRUCTION. SPECIFIC OBJECTIVES WERE TO: (1) DEVELOP, FOR TYPICAL ILLINOIS SURFICIAL DEPOSITS, GUIDELINES AND CRITERIA NECESSARY TO DETERMINE THE APPLICABILITY OF CURRENT MATEIALS BENEFICIATION TECHNIQUES; AND (2) DEVELOP, FOR SPECIFIC ILLINOIS SURFICIAL SOILS AND MATERIALS, FEASIBILITY RECOMMENDATIONS THAT WILL PROVIDE FOR EFFECTIVE AND ECONOMICAL UTILIZATION OF VARIOUS STABILIZATION TECHNIQUES AND PROMOTE MAXIMUM UTILIZATION OF LOCAL MATERIALS. THE PEDOLOGICAL SOIL CLASSIFICATON SYSTEM WAS USED TO IDENTIFY AND CLASSIFY SOILS OF SIMILAR CHARACTERISTICS RELATIVE TO SOIL STABILIZATION. THHE SOIL ASSOCIATION AREA CONCEPT WAS USED TO COMBINE PEDOLOGIC SOIL SERIES INTO GROUPS WITH SIMILAR CHARACTERISTICS AND TO FACILITATE PRESENTATION OF PERTINENT DATA AND FEASIBILITY RECOMMENDATIONS. EXTENSIVE SOIL DATA NECESSARY TO PROPERLY APPLY THE STABILIZATION GUIDELINES AND CRITERIA WERE OBTAINED FROM TH DEPARTMENT OF AGRONOMY, UNIVERSITY OF ILLINOIS, THE SOIL CONSERVATION SERVICE, THE UNIVERSITY OF ILLINOIS ENGINEERING EXPERIMENT STATION PUBLICATONS, AND VARIOUS OTHER SOURCES OF PUBLISHEDAND UNPUBLISHED DATA. ALTHOUGH STABILIZATION RECOMMENDATIONS WERE PRESENTED ONLY FOR MAJOR SOILS WITHIN EACH SOIL ASSOCIATION AREA, BY UTILIZING THE GUIDELINES AND CRITERIA THAT WERE DEVELOPED FOR THE SOILS OF ILLINOIS AND BY APPROPRIATE CONSIDERATION OF STABILIZATION TECHNOLOGY, STABILIZATION FEASIBILITY RECOMMENDATIONS CAN BE READILY DETERMINED FOR OTHER SOILS. THE INFORMATION THAT CAN BE OBTAINED FROM A REPORT CONTAINING STABILIZATION RECOMMENDATIONS OF THIS TYPE IS MEANT TO FACILITATE THE SELECTION OF A STABILIZING AGENT OR AGENTS AND TO PROMOTE MAXIMUM USE OF LOCAL MATERIALS IN VARIOUS HIGHWAY CONSTRUCTION APPLICATIONS. APPROPRIATE MIXTURE DESIGN PROCEDURES MUST BE USED TO SATISFY JOB REQUIREMENTS FOR PARTICULAR APPLICATIONS. ECONOMIC CONSIDERATION, IN MANY CASES, MAY BE VERY IMPORTANT AND WILL OFTEN BE USED IN THE FINAL SELECTION OF A STABILIZING AGENT.

Experimental stabilization of pierre shale

Abstract: THE EXPERIEMENTAL STUDY WAS INITIATED WITH A THREEFOLD PURPOSE IN MIND: (1) TO DETERMINE IF IT IS POSSIBLE TO ACHIEVE THE DEGREE OF STABILITY NECESSARY TO PREVENT WARPING OF ROAD SURFACING MATERIALS BY THE ADDITION OF CHEMICALS OR OTHER ADDITIVES TO THE HIGHLY EXPANSIVE IN-PLACE SOILS OVER WHICH THESE SURFACING MATERIALS ARE PLACED; (2) TO DETERMINE IF THE USE OF ADDITIVES IN THE IN-PLACE SOILS IS MORE EFFECTIVE IN REDUCING WARPING THAN REPLACING WITH NONEXPANSIVE MATERIALS; AND (3) TO DETERMINE, TO A CERTAIN DEGREE, THE ECONOMY OF USING STABILIZING AGENTS IN THE IN-PLACE SOIL AS COMPARED TO HAULING IN NONEXPANSIVE MATERIAL. THE EXPERIMENTAL ROAD INCLUDES THE FOLLOWING TYPES OF STABILIZATION IN THE UPPER 6 OR 9 IN. OF SOIL SUBGRADE: LIME STABILIZATION, LIME-ASPHALT STABILIZATION, PHOSPHORIC ACID PLUS FERRIC SULPHATE, AND PDC FORMULA (4 PARTS LIME, 2 PARTS CEMENT, AND 1 PART SOY FLOUR). CONTROL SECTIONS ARE COMPOSED OF STANDARD DESIGN METHODS, INCLUDING SELECT SOIL, OR NONEXPANSIVE SOIL, VARYING IN THICKNESS FROM 6 TO 18 IN. IN CONJUNCTION WITH A 3- TO 6-IN. THICKNESS OF STANDARD TYPE B SUBBASE, 5 IN. OF STANDARD TYPE II BASE COURSE, AND A 2-IN. CLASS F MAT. ONE SPECIAL CONTROL SECTION HAS 30 IN. OF SELECT SOIL. TWO OTHER CONTROL SECTIONS HAVE THE EARTH SUBGRADE UNDERCUT TO A DEPTH OF 36 IN. THE UNDERCUT SOIL WAS REPLACED AND RECOMPACTED PRIOR TO PLACEMENT OF SURFACING MATERIALS. AT THE END OF THE 4-YEAR STUDY PERIOD, ALL OF THE STABILIZING AGENTS HAVE ALTERED THE PHYSICAL CHARACTERISTICS OF THE PIERRE SHALE TO SOME DEGREE. LIME APPEARS TO HAVE THE MORE PERMANENT EFFECT. THE SERVICEABILITY INDEX RATINGS INDICATE THAT ALL OF THE STABILIZED SECTIONS EXCEPT PHOSPHORIC ACID ARE BETTER THAN IN THE STANDARD DESIGN SECTIONS. ALL OF THE TREATED SOILS HAVE A HIGHER CBR VALUE AFTER A 4-YEAR PERIOD THAN THE RAW SOIL. THE PHOSPHORIC ACID SECTION IS ONLY SLIGHTLY HIGHER THAN THE RAW SOIL. LIME- TREATED SOILS, AND ADDITIVES IN COMBINATION WITH LIME, APPARENTLY RECOVER SOME BEARING STRENGTH AFTER SUFFERING A LOSS OF STRENGTH DUE TO FREEZING. SERVICEABILITY INDEX RATINGS INDICATE THAT TREATED SOILS TEND TO BE MORE EFFECTIVE IN REDUCING SURFACE WARPING THAN THE USE OF NONEXPANSIVE SOILS OVER THE PIERRE SHALE. IT APPEARS THAT THE USE OF STABILIZING AGENTS CAPABLE OF MAINTAINING A PERMANENT CHANGE IN THE PHYSICAL CHARACTERISTICS OF THE SOIL WOULD BE MORE ECONOMICAL THAN THE USE OF NONTREATED SOILS BY REDUCING THE LONG-RANGE MAINTENANCE COSTS. STABILIZING AGENTS CAPABLE OF MAINTAINING HIGHER STABILITY AND BEARING CAPACITY IN THE TREATED LAYERS THROUGHOUT THE YEAR WILL ALLOW THE DESIGN OF THINNER SURFACING COMPONENTS. /AUTHOR/