Showing papers on "Soil stabilization published in 2004"

Studies on Sulfate-Resistant Cement Stabilization Methods to Address Sulfate-Induced Soil Heave

Abstract: Performance of pavements has been affected by heave distress problems caused by sulfate rich soils treated with calcium-based stabilizers. A research study was conducted to address the effectiveness of sulfate resistant cement stabilizers Types I/II and V, for providing better treatment of sulfate rich soils. Experiments were designed and conducted on both control and cement treated sulfate soils to investigate compaction relationships, Atterberg limits, linear shrinkage and free swell strain potentials, unconfined compressive strength, and low strain shear moduli properties. This paper presents a comprehensive summary and analysis of these test results. Test results were statistically analyzed to study the potentials of sulfate resistant cement stabilization methods for significant enhancements to the strength and stiffness properties as well as reductions in swell and shrinkage strain potentials of natural sulfate rich soils. Mineralogical studies were used to verify research findings observed from the macro test results.

Limit loads on reinforced foundation soils

Abstract: Reinforced soil is a practical solution to construction of unpaved roads or placement of footings over weak soils. A stability analysis of reinforced foundation soil is presented in this paper. A method is suggested for calculating limit loads on strip footings over foundation soils reinforced with horizontal layers of geosynthetics. Separate solutions are given for a case where reinforcement layers slip within the soil, and for a case where reinforcement ruptures. In the former case, an increase in the bearing capacity is dependent on the characteristics of the soil-reinforcement interface, whereas in the latter case it depends on the strength of the reinforcement. In both cases the increase in the limit load is dependent on the internal friction angle of the soil. Expressions are developed for quantitative predictions of bearing capacity of the foundation soil with horizontal layers of reinforcement. An optimum reinforcement depth is also given.

New Method for Prediction of Loads in Steel Reinforced Soil Walls

Abstract: The paper describes a new working stress design methodology introduced by the writers for geosynthetic reinforced soil walls (K-Stiffness Method) that is now extended to steel reinforced soil walls...

An overview of waste materials recycling in the Sultanate of Oman

Abstract: Various wastes and by-product materials are generated in the Sultanate of Oman including reclaimed asphalt pavement (RAP) aggregate, demolition concrete, cement by-pass dust (CBPD), copper slag, petroleum-contaminated soils (PCS), discarded tires, incinerator ash, and others. Recycling of such materials in construction is not practiced. Research data are also minimal into the potential use of selected materials in construction applications. This paper will present the results of several laboratory studies conducted into the use of PCS in asphalt concrete mixtures; on the use of CBPD in soil stabilization and flowable fill mixtures; on the utilization of copper slag and CBPD as cementitious materials; on the use of incinerator ash in cement mortars; and on the use of RAP aggregate in road bases and sub-bases. Laboratory data generally indicate that it is feasible to partially reuse some of these materials in construction provided that economic incentives and environmental concerns are taken into consideration.

Use of Cement Kiln Dust for the Stabilization of Soils

Abstract: Stabilization of soils is an effective method for improving soil properties and pavement system performance. Cement kiln dust (CKD) represents an alternative to the tradition stabilization agents of lime, cement, and Class C fly ash. As with the other additives, cement kiln dust can be expected to vary in effectiveness depending on the soil type. A total of eight different soils with classifications of CH, CL, ML, SM, and SP were subjected to a series of durability tests, including freeze-thaw, wet-dry, and leach testing, to evaluate the relative performance of CKD as a stabilization agent. Results were compared with previous findings for the same soils stabilized with lime, cement, and fly ash. Atterberg limits and strength tests were conducted before and after selected durability tests. Relative values of soil stiffness were also tracked over a 28-day curing period using the soil stiffness gauge to evaluate ongoing reactions. The results provide guidance on which soil types can be expected to have significant improvements in performance wit the addition of CKD.

New Zealand Experience with Foam Bitumen Stabilization

Abstract: Foamed bitumen stabilization is burgeoning steadfastly and internationally. Although it involves higher initial material costs than cement or lime stabilization, it offers the advantages of being free from transverse shrinkage cracking and of being a fast technique that minimizes traffic delays. This work forms part of a larger project aimed at investigating the feasibility and potential applications of the foamed bitumen stabilization technique to speed its adoption in New Zealand. In this research, the foaming characteristics of two sources each of two grades of bitumen currently in use in New Zealand are presented. The effect of bitumen source and grade and the type of fines were studied. Fly ash Type C was used to modify the aggregate gradation to adjust the percentage of the fine fraction (passing the 75μm sieve). Portland cement was used at 2% by the dry weight of aggregates as a partial replacement for the fly ash. The foamability results for each source were quite different. For each source, the s...

Soil Isolation for Seismic Protection using a Smooth Synthetic Liner

Abstract: A synthetic liner consisting of a nonwoven geotextile over an ultrahigh molecular weight polyethylene, geotextile/UHMWPE, placed within a soil profile can dissipate seismic energy transmitted to the overlying soil layer and structure. This concept of soil isolation can be an effective and inexpensive way of reducing seismic ground motions through slip displacements. Shaking table tests on soil layers isolated using cylindrical and tub-shaped liners were conducted using harmonic and earthquake base excitations. The results show that an isolation liner can significantly reduce the accelerations at the surface of the isolated soil mass. Accompanying such a reduction in accelerations are slip displacements that manifest around the perimeter of the isolated soil. Because of the curved nature of the liner, permanent slips are minimized by the restoring effect of the gravitational forces of the isolated soil mass. Analytical results under field scale conditions indicate that a soil isolation liner can dramatically reduce the peak and spectral accelerations of a vertically propagating shear wave. Such a reduction can provide seismic protection to a structure founded on soil-isolated ground.

Case study of subgrade stabilization using fly ash: state highway 32, port washington, wisconsin

Abstract: This paper describes a case history where Class C fly ash, an industrial byproduct of electric power production, was used to stabilize a sandy clay highway subgrade is that a firm working platform could be provided for pavement construction. California bearing ratio (CBR), resilient modulus (M sub r), and unconfined compressive strength tests were conducted on the soil alone and the soil-fly ash mixture to assess how fly ash improves the bearing resistance, stiffness, and shear strength of the soil. Field tests were also conducted during construction using a soil stiffness gauge (SSG) and a falling weight deflectometer (FWD) to assess the stiffness and modulus of the stabilized soil in situ. CBRs ranging from 46 and 150 were obtained of the stabilized soil after 7 d of curing, whereas the soil typically has CBR near 0 in its naturally moist condition.

Use of Cement Kiln Dust for Subgrade Stabilization: Final Report

Abstract: Poor subgrade soil conditions can result in inadequate pavement support and reduce pavement life. Soils may be improved through the addition of chemical or cementitious additives. These chemical additives range from waste products to manufactured materials and include lime, Class C fly ash, portland cement, cement kiln dust from pre-calciner and long kiln processes, and proprietary chemical stabilizers. These additives can be used with a variety of soils to help improve their native engineering properties. The effectiveness of these additives depends on the soil treated and the amount of additive used. This report contains a summary of the performance of a wide range of soils treated with pre-calciner cement kiln dust (CKD), and is intended to be viewed as a companion report to the previously published Kansas Department of Transportation report, "Performance of Soil Stabilization Agents." CKD has been used as a soil additive to improve the texture, increase strength and reduce swell characteristics. CKD was combined with a total of eight different soils with classifications of CH, CL, ML, SM, and SP. Durability testing procedures included freeze-thaw, wet-dry, and leach testing. Atterberg limits and strength tests were also conducted before and after selected durability tests. Changes in pH were monitored during leaching. Relative values of soil stiffness were also tracked over a 28-day curing period using the soil stiffness gauge. Treatment with CKD was found to be an effective option for improvement of soil properties, based on the testing conducted as a part of this research. Strength and stiffness were improved and plasticity and swell potential were substantially reduced. Durability of CKD treated samples in wet-dry testing was comparable to that of soil samples treated with the other additives, while performance was not as good in freeze thaw testing. CKD treated samples performed very well in leaching tests and in many cases showed additional reductions in plasticity and some strength gains after leaching. It is recommended based on the results of this research that CKD be considered a viable option for the stabilization of subgrade soils. As with all additives, it is recommended that a mix design be conducted prior to selection to confirm the CKD selected and the amount specified will provide satisfactory performance.

Performance of soil stabilization agents

Abstract: Poor subgrade soil conditions can result in inadequate pavement support and reduce pavement life. Soils may be improved through the addition of chemical or cementitious additives. Such chemical additives range from waste products to manufactured materials and include lime, Class C fly ash, portland cement and proprietary chemical stabilizers. These additives can be used with a variety of soils to help improve their native engineering properties. This report contains a summary of the performance of lime, cement, Class C fly ash, and Permazyme 11-X used with a wide range of soils. Each of the chemical additives tested is designed to combine with the soil to improve the texture, increase strength and reduce swell characteristics. These products were combined with a total of eight different soils with classifications of CH, CL, ML, SM, and SP. Durability testing procedures included freeze-thaw, wet-dry, and leach testing. Atterberg limits and strength tests were also conducted before and after selected durability tests. Changes in pH were monitored during leaching. Relative values of soil stiffness were also tracked over a 28-day curing period using the soil stiffness gauge. Lime and cement stabilized soils showed the most improvement in soil performance for multiple soils, with fly ash treated soils showing substantial improvement. The results showed that for many soils more than one stabilization option may be effective for the construction of durable subgrades. The enzymatic stabilizer did not perform as well as the other stabilization alternatives. It is recommended, based on the results of this research, that some testing of the contribution of proposed stabilization agents be conducted prior to construction. For pavement designs that expect a relatively limited strength contribution from the soil, the primary anticipated benefit of stabilization is generally the control of volume change.

Use of cement kiln dust for subgrade stabilization

Abstract: Poor subgrade soil conditions can result in inadequate pavement support and reduce pavement life. Soils may be improved through the addition of chemical or cementitious additives. These chemical additives range from waste products to manufactured materials and include lime, Class C fly ash, portland cement, cement kiln dust from pre-calciner and long kiln processes, and proprietary chemical stabilizers. These additives can be used with a variety of soils to help improve their native engineering properties. The effectiveness of these additives depends on the soil treated and the amount of additive used. This report contains a summary of the performance of a wide range of soils treated with pre-calciner cement kiln dust (CKD), and is intended to be viewed as a companion report to the previously published Kansas Department of Transportation report, "Performance of Soil Stabilization Agents." CKD has been used as a soil additive to improve the texture, increase strength and reduce swell characteristics. CKD was combined with a total of eight different soils with classifications of CH, CL, ML, SM, and SP. Durability testing procedures included freeze-thaw, wet-dry, and leach testing. Atterberg limits and strength tests were also conducted before and after selected durability tests. Changes in pH were monitored during leaching. Relative values of soil stiffness were also tracked over a 28-day curing period using the soil stiffness gauge. Treatment with CKD was found to be an effective option for improvement of soil properties, based on the testing conducted as a part of this research. Strength and stiffness were improved and plasticity and swell potential were substantially reduced. Durability of CKD treated samples in wet-dry testing was comparable to that of soil samples treated with the other additives, while performance was not as good in freeze thaw testing. CKD treated samples performed very well in leaching tests and in many cases showed additional reductions in plasticity and some strength gains after leaching. It is recommended based on the results of this research that CKD be considered a viable option for the stabilization of subgrade soils. As with all additives, it is recommended that a mix design be conducted prior to selection to confirm the CKD selected and the amount specified will provide satisfactory performance.

Fly Ash Amended Soils as Highway Base Materials

Abstract: Class F fly ash cannot be used alone in soil stabilization applications as it is not self-cementing. An activator such as Portland cement or lime must be added to produce cementitious products often called pozzolan stabilized mixtures. The developed mixture must possess adequate strength and durability, should be easily compacted, and most importantly should be economical and environmentally friendly. Roadways have a high potential for large volume use of the fly ash stabilized soils. The main objective of this study is to investigate the beneficial reuse of Class F fly as amended soil-cement or soil-lime as base layers in highways. A battery of tests was conducted on soil-fly ash mixtures prepared with cement and lime as activators. Unconfined compression, California bearing ratio, and resilient modulus tests were conducted. Results of the study show that strength of a mixture is highly dependent on the cuing period, the compactive energy, cement content, and water content at compaction. Lime treatment does not provide sufficient strength for designing the mixtures as highway bases. A power function in terms of bulk stress used for granular soils can model the resilient moduli.

Compression and uplift of Rammed Aggregate Piers in clay

Abstract: Full scale compression and uplift load tests were conducted on 3 Rammed Aggregate Piers (trademark Geopier) in the upper surficial clay fill at the NGES (National Geotechnical Experimentation Site) located at the University of Massachusetts, Amherst. The tests were conducted to evaluate the performance of this intermediate foundation system in a fine-grained soil. The field investigation also included measurements of vertical and lateral soil deformation to evaluate the active zone of soil resistance. The results show viable uplift and bearing capacity application for the foundation system in fine grained soils. Possible applications include foundation support and/or as a form of ground improvement.

Stabilization of clay and residual soils using cement - rice husk ash mixtures

Abstract: The well established techniques of soil stabilization often use such cementing agents as Portland cement, lime, etc. Replacement of those cementing materials with industrial or agricultural by-product is highly desirable. Rice husk ash is a very potential paddy crop waste as pozzolanic materials which result in a superior properties when combined with cement or other cementing agents. This paper presents the laboratory study on the stabilized soils with cement and rice husk ash. The experimental study included the evaluation of such properties of the soil as consistency limits, compaction, unconfined compressive strength, and X-Ray diffraction. Three types of soils are used in this study i.e granite residual soils, kaolinite clay and montmorillonite clay (bentonite). Test results show that both cement and rice husk ash reduces the plasticity of soils. In term of compactability, addition of rice husk ash and cement decreases the maximum dry density and increases the optimum moisture content. From the viewpoint of plasticity, compaction and strength characteristics, and economy, addition of 6 – 8 percent cement and 10 – 15 percent rice husk ash are recommended as an optimum amount for soils stabilization.

Case History of Deep Mixing Soil Stabilization for Boston Central Artery

Abstract: This paper presents a case history of the deep mixing method (DMM) as it was developed and applied over a period of ten years during construction of the Boston Central Artery and Tunnel (CA/T). Deep deposits of marine clay were stabilized with DMM for large open cuts as Bird Island Flats and Fort Point Channel, both of which are described with respect to site conditions, soil properties, DMM installation and characteristics, and measured field performance. Topics addressed in this paper include water pressure distribution behind DMM walls, statistical characterization of soil-cement properties, quality control/quality assurance procedures, comparison of measured and numerically simulated deformation in clay stabilized with various configurations of soil-cement elements, and shear modulus degradation characteristics of in situ soil-cement. Recommendations are made for soil cement properties, installation procedures, analytical modeling, design, and inspection.

Impact of Sand Dune Stabilization Structures on Soil and Yield of Millet in the Semi-Arid Region of NW Nigeria

Abstract: The low-rainfall ecologies of the northern fringes of Nigeria are prone to desertification and sand dune activities that are phenomenal and extensive. Stabilization structures put in place by various governmental and non-governmental agencies to check desertification in northwestern Nigeria were evaluated with respect to efficiency, impact on soil development and yield of millet. The study focused on the active and stabilized sand dune formations in NW Nigeria. Various stabilization techniques were identified within Gidan Kaura (the study site) and results were compared with an unstabilized sand dune (control site). Results obtained indicated that the sand dunes within the study area are still active despite the numerous stabilization structures, some of which were established over 15 years ago. Shelterbelts were the most effective techniques in sand dune stabilization and soil development when properly sited across wind direction. Shelterbelts recorded significantly higher levels of pH, organic carbon, total nitrogen, exchangeable bases and micronutrients except for copper, when compared with all other treatments. The least effective of all the structures was mechanical fencing, probably due to the inadequate quantity of plant residues used in its construction. The impact of the various structures on the physical and chemical soil properties was evaluated for surface soils as were the structures on the yield of millet in stabilized dunes and non-dune areas. The results are discussed in depth in this paper.

Strength Properties of Cement Treated Coode Island Silt by the Soil Mixing Method

Abstract: Coode Island Silt (CIS) is one of the youngest formed sedimentary foundations in the Melbourne geological region of the Yarra Delta. Because it is a highly compressible material, CIS imposes geotechnical constraints on the design and performance of infrastructure works. This paper investigates the effectiveness of using soil mixing technology via cement stabilization of CIS by studying the improvement of the strength of treated soils. Tests were carried out in two stages: (1) laboratory based stabilization of CIS; and (2) small scale model mixing. The improvement in terms of strength was assessed using unconfined compressive strength (UCS) test. A small-scaled model mixing was set up to mimic the actual mixing scenario on sites. Although it may not be perfect, it gives an indication on the effectiveness of the cement slurry when combining with the silty clay.

Application of Conditioner Solution by Subsurface Emitters for Stabilizing the Surrounding Soil

Abstract: Poor uniformity of water application by subsurface drip irrigation has been examined and some explanations are suggested in this paper. Use of soil conditioners for soil structure stabilization around subsurface drip irrigation pipes was suggested by the authors and tested in the laboratory. The conditioners preserve the structure of existing aggregated and may effectively reduce soil clogging. A silt loam soil was uniformly packed in a 13 0.83 0.15 m box. Two holes were dilled in the box wall through which two emitters were inserted, one for applying solution of soil conditioner and one as a control. Stabilization was achieved by applying two types of polymer solutions differing by their molecular weights through an emitter buried in a silt loam soil. A measured water volume was injected through the emitters into the soil and, after 48 h following irrigation, the box was dismantled. Gravimetric soil moisture content and aggregate water stability were measured in vertical and horizontal distances from the emitter. The highest stabilizing effectiveness was obtained with a volume of 1.5 L polymer solution at 5 g / L concentration, which was applied to the soil at an initial moisture content of 13%. The volume of stabilized soil increased with the volume of applied solution, but the volume ratio of stabilized soil to applied solution decreased with the increase in solution volume. A polymer of relatively low molecular weight was found less effective since a large portion of the solution was consumed by fast penetration into soil aggregates without improving the soil structure. The proposed method offers a simple and easy means for preparing a stabilized soil envelope around subsurface drip irrigation pipes, which may improve the long-term performance and uniformity of the application of these systems. Yet for some of these aspects, further field evaluation is needed, since the results of the study are from a laboratory experiment limited to one soil only.

Time Domain Reflectometry for Compaction Control of Stabilized Soils

Abstract: Chemical stabilization is widely used in geotechnical engineering to improve the engineering properties of geomaterials. The interaction between the stabilizers and soil particles changes the physicochemical structure of these materials and increases their performance. Water content and density are the indicators used in field practice for construction quality control of the stabilized soils. The nuclear method is currently the preferred technology for field measurement of water content and dry density in geotechnical engineering. However, the nuclear method has been found to give inaccurate results when used on stabilized soils. Researchers at Purdue University developed a procedure to measure soil water content and dry density using time domain reflectometry (TDR). Tests performed on conventional soils indicate that this procedure is accurate and fast. The feasibility of this technology on the stabilized soils was investigated; the preliminary conclusion was that TDR achieves satisfactory accuracy. In a...

Structural support of lime or cement stabilized subgrade used with flexible pavements

Abstract: Lime or cement stabilizations have been used to modify wet and soft roadbed soils so that the roadbed can carry the load of construction vehicles without excessive rutting. Lime stabilization is recommended for fine-grained and high plasticity soils, and cement stabilization is recommended for coarse-grained and low plasticity soils. The durability and structural benefits of the stabilized road bed soils have been investigated in this study through four tasks. First, the in-situ conditions of stabilized subgrade were investigated using the Dynamic Cone Penetrometer (DCP) test. The results show that the moduli of stabilized soils are generally higher than non-stabilized soils several years after construction. The second task investigated the durability and strength characteristics of stabilized soils through laboratory tests. Unconfined compressive strength, California Bearing Ratio, and resilient modulus of stabilized soils are all higher than non-stabilized soils. After freezing and thawing cycles, the stabilized soils retain more strength and modulus than the non-stabilized soils. The third task evaluated the conditions of 4 test sections on State Route 2 in Erie County, with subgrade stabilized with 6% cement, 5% lime, 3% lime with 3% cement, respectively, and a control section with no stabilization. Pavement deflection measurements were taken during different stages of construction and for each of the 3 years after construction. The backcalculated subgrade moduli show that stabilization increases the subgrade modulus, with the cement treated soil being the strongest initially, followed by the 3% lime plus 3% cement section. However, the lime stabilized subgrade continues to gain strength three years after construction. The cement stabilized section has sandy soils, while the other sections have clayey soils. The fourth task developed a design procedure to quantify the increase in strength and modulus as an "effective" subgrade modulus in order to include the structural benefit of stabilized subgrade in the current pavement thickness design procedure.

Assessment of sulfate-bearing ground for soil stabilisation for built development

Abstract: The addition of lime and cement to clay soils to improve their engineering characteristics is a well-established method, but in some cases the stabilised layer fails to meet specifications due to sulphate attack resulting in ground heave and softening. Sulphates in the ground react with the lime or cement to form the expansive sulphate hydrates ettringite and thaumasite. Both these hydrates were formed during the construction of the Banbury section of the M40 motorway. Guidance on the assessment of sulphates and sulphides in materials stabilised for use in highway construction is given in Highways Agency publication HA 74/00 and new European standards (BS EN 13286 Parts 1 to 53). Details are given of tests for total sulphate, total sulphur, sulphate in 2:1 water/soil extract, sulphate in total groundwater, and swelling tests. A strategy for clay site and material appraisal is presented.

A compendium of ground modification techniques

Abstract: Increased growth has led to the need to use marginal sites, and because many soils can be made into useful construction material when properly modified, ground modification has become a viable consideration for many infrastructure projects. This report summarizes the advantages/limitations, appropriate selection of ground modification technique, and design considerations for the following ground modification techniques: (1) compaction, (2) deep dynamic compaction, (3) surcharging (preloading), (4) stone columns, (5) soil stabilization, (6) grouting, (7) jet grouting, (8) deep soil mixing, (9) mechanically stabilized earth (MSE) walls, (10) reinforced slopes, (11) soil nailing, (12) geogrids in highways, and (13) lightweight fills.

Stabilization of Retaining Walls and Embankments using Rammed Aggregate Piers TM

Abstract: Highway construction often requires the placement of embankments and earth retaining walls to facilitate grade separations. Instability and settlement occur when these structures are placed on top of weak and compressible soils. Historically, the severity of these problems have been reduced using toe berms and surcharging. More recently, Rammed Aggregate Piers have been used to avoid the need for extending large right-of-ways required for toe berm construction or for time-consuming surcharging. The installation of Rammed Aggregate Piers reinforces weak and compressible foundation soils prior to construction of earth embankments and walls. The installation of Rammed Aggregate Piers increases the factor of safety against slope stability as a result of the high angle of internal friction (48 to 52 degrees) achieved during ramming and reduces the magnitude and time of settlement by increasing the overall stiffness of the foundation soils and providing a drainage pathway for dissipation of excess pore water pressure. This paper presents analytical methods used to design Rammed Aggregate Piers to reinforce weak soils and control settlements below highway and railroad retaining walls and embankments. The analytical methods are illustrated by a case history for a Mechanically Stabilized Earth (MSE) wall support project near Houston, Texas. This work is of particular significance because it presents design methodologies and a case history for an effective ground reinforcement technique increasingly used to support highway embankments and walls.

Constitutive Analyses of Nontraditional Stabilization Additives

Abstract: : Personnel of the U.S. Army Engineer Research and Development Center (ERDC), Vicksburg, MS, conducted a series of laboratory experiments designed to characterize the constitutive properties of selected soil minerals and nontraditional stabilization additives. The results of these experiments were analyzed and included in this report to document the baseline characteristics prior to mixing the stabilizers and individual soil minerals. Analyses of the potential of individual stabilization products to reinforce specific soil types were conducted and reported. Additionally, an experimental modeling approach for describing the reinforcement mechanisms of individual stabilization agents was developed.

Industrial solid waste (whitewash mud) use in forest road pavements

Abstract: The objective of the present study was to evaluate the effects of industrial solid waste (whitewash mud) on geotechnical properties considering the following engineering parameters: California Bearing Ratio (CBR), Atterberg limits and Permeability test. Seven soil samples derived from Alagoinhas, Bahia - Brazil, were classified by the Transportation Research Board (TRB) system. Two were selected as having a great geotecnical potential classified as A-3 (0) and A-2-4 (0), whitewash mud contents 10%, 15%, 20% and 25% dry weight and medium compaction effort were studied in the laboratory testing program. The results indicated the soil denominated good gravel as being the most promising one, when stabilized with whitewash mud, reaching the best results with the dosage of 20 and 25% of whitewash mud.

Afforestation/soil stabilization material having pollutant elution inhibitory effect, thick-layer base material hydroseeding method using the same, soil stabilization method and method for processing polluted soil

Abstract: PROBLEM TO BE SOLVED: To provide an afforestation/soil stabilization material which is used for thick-layer base material hydroseeding method or a soil stabilization processing method, is capable of forming an excellent surface within a short time and is capable of inhibiting elusion of pollutants from soil. SOLUTION: The afforestation/soil stabilization material effective in inhibiting the elution of pollutants is prepared by mixing 10-80 pts.mass first additive and 0.2-20 pts.mass second additive against 100 pts.mass ash component, wherein the first additive contains at least calcium sulfate and a cement component and the second additive essentially comprises an iron powder, calcium oxide and aluminum oxide. COPYRIGHT: (C)2006,JPO&NCIPI

Method of selecting a soil stabilization protocol for a construction site

Abstract: There is disclosed a method of selecting in real time a soil stabilizing protocol for clay-bearing soils occurring in construction sites, comprising the steps of: obtaining soil conductivity data values at selected locations within a defined site without disturbing the surface of the soil; correlating the soil conductivity data values with corresponding estimates of soluble sulfate levels; recommending a calcium-based soil stabilizing protocol if the estimated level of soluble sulfates is less than a predetermined threshold; and performing a laboratory analysis of soil samples from selected portions of the defined site wherein the estimated soluble sulfate concentration equals or exceeds the predetermined threshold.