Swell Shrink Research Articles

Ancient and historical cooking pots and food: an eternal communion. A topical review

AbstractThis contribution provides a topical view at and review of traditional clay‐based utilitarian cooking pots that were used for millennia to prepare, serve, display, and distribute foodstuff. Key mechanical and thermal properties of ceramic cooking vessels will be discussed and strategies of property optimization outlined. In addition, some important chemical changes food constituents undergo during cooking will be explained. Mass‐produced ancient ceramic cooking pots from Neolithic Mesopotamia have revolutionized the art of cooking by allowing foodstuff to be processed in water. As an example of successfully optimizing the properties of cooking vessels, emphasis is being given to Indigenous prehistoric North American ware of the Mississippian culture (c. 800 to 1600 CE) that show impressively how ancient potters overcame the technological challenges posed by essentially unsuitable smectite‐rich clays with extreme plasticity and high swell–shrink ratio by adding copious amounts of burnt mussel shells as temper material.

Flow through and Volume Change Behavior of a Compacted Expansive Soil Amended with Natural Biopolymers

Natural biopolymers offer a sustainable alternative for improving soil behavior due to their inert nature, small dosage requirement, and applicability under ambient temperatures. This research evaluates the efficacy of natural biopolymers for ameliorating an expansive soil by using a 0.5% dosage of cationic chitosan, charge-neutral guar gum, and anionic xanthan gum during compaction. The results of laboratory investigations indicate that the flow through and volume change properties of the expansive soil were affected variably. The dual porosity, characterized by low air entry due to inter-aggregate pores (AEV1 of 4 kPa) and high air entry due to the clay matrix (AEV2 of 200 kPa) of the soil, was healed using chitosan and guar gum (AEV of 200 kPa) but was enhanced by the xanthan gum (AEV1 of 100 kPa and AEV2 of 200 kPa). The s-shaped swell–shrink path of the soil comprised structural (e from 1.23 to 1.11), normal (e from 1.11 to 0.6), and residual stages (e ranged from 0.6–0.43). This shape was converted into a j-shaped path through amendment using chitosan and guar gum, showing no structural volume change, with e from about 1.25 to 0.5, but was reverted to a more pronounced form by xanthan gum, with e from 1.5 to 1.32, 1.32 to 0.49, and 0.49 to 0.34 in the three stages, respectively. The consolidation behavior of the soil was largely unaffected by the addition of biopolymers such that the saturated hydraulic conductivity decreased from 10−9 m/s to 10−12 m/s over a void ratio decrease from 1.1 to 0.6. At a seating stress of 5 kPa, the swelling potential (7.8%) of the soil slightly decreased to 6.9% due to the addition of chitosan but increased to 9.4% and 12.2% with guar gum and xanthan gum, respectively. The use of chitosan and guar gum will allow the compaction of the investigated expansive soil on the dry side of optimum.

Influence of Solid Waste Oyster Shell Powder on the Physical and Swell–Shrink Properties of Expansive Soils

Influence of Solid Waste Oyster Shell Powder on the Physical and Swell–Shrink Properties of Expansive Soils

Time-dependent swell–shrink behavior of red-bed mudstone under cyclic wetting and drying

Time-dependent swell–shrink behavior of red-bed mudstone under cyclic wetting and drying

Effect of calcined clay on the improvement of compaction, swell and microstructural characteristics of expansive soil

Expansive soil is problematic soil because its alternate swell shrink behaviour depends on the presence of water. Soil stabilization technique was widely adopted to alter the characteristics of the expansive soil which is suitable for construction. Among the various soil stabilization techniques, chemical stabilization was found to be more suitable method of sustainable stabilizing the soil due to its effective and timely reaction with the chemical compound. Calcined form of clay material is used as an admixture to study the effects on the improvement of soil properties. Calcined Clay (CC) is added into the virgin soil with different percentages of 2%,4%,6%,8% and 10% under varying 1,3,7,14,28 and 60 days of curing by conducting experiments such as standard proctor test, Free Swell test to analyse the compaction characteristics and swelling behaviour of the soil. In addition to that the X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM) on virgin and treated soil were studied by varying 2% incremental of CC up to 10% at 28 days of curing. From the test results it shows the variation in the compaction characteristics by rising in Maximum Dry Density (MDD) and reduction in Optimum Moisture Content (OMC) that merges at 8% as an optimum to develop the soil behaviour and from the free swell test, it was found that the Free Swell Index (FSI) of the soil decrease from 210 to 80 at 10% calcined clay added soil and the Mineralogical studies also show the variation in the compounds. Thus, this naturally available calcined clay was used to improve the soil Compaction and swell characteristics that influences the reduction in deformation and increase in shear strength of soil which helped to minimize the environmental problem as well as one of the effective admixtures to improve the expansive soil characteristics.

Sustainable Lignin to Enhance Engineering Properties of Unsaturated Expansive Subgrade Soils

New ways to apply sustainable materials, such as biomass components, are essential for reducing dependence on fossil fuels. This work investigated the engineering properties of unsaturated expansive subgrade soils stabilized by bio-based energy coproducts containing lignin. Lignin is a waste by-product of the paper and pulp industry that is frequently burned. Highway subgrade could consume lignin as an environmentally benign, low-cost, and energy-efficient chemical substance for soil stabilization. Swell and shrink behavior of expansive subgrade soils complicates highway construction and causes damage to existing highways. However, research on the hydromechanical properties and volume change behavior of lignin-stabilized expansive soil is limited, and better insight is required into its unsaturated behavior for safe and economical pavement design practices. In this research, a series of geotechnical laboratory tests were conducted to characterize expansive subgrade soils treated with lignin by determining the Atterberg limits, compaction and consolidation behaviors, swelling characteristics, and water retention properties. The mechanisms influencing the changes in engineering properties of lignin-treated expansive soils were further investigated using soil pH, scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy analysis. The study shows that the optimal lignin content contributed to an acceptable degree of soil stabilization. The lignin-based cementing material effectively bonds soil particles together and fills pores, thereby preventing water infiltration into the soil and reducing the swell–shrink potential of stabilized soils.

Effects of Phase Change Materials on the Freeze–Thaw Performance of Expansive Soil

Freeze–thaw cycles can deteriorate the expansive soil performance. Phase change materials (PCMs) absorb and store heavy latent heat from the environment, which can be utilized to mitigate freeze–thaw deteriorations in expansive soil. In this study, an environmentally friendly paraffin-based PCM was selected, which included two different forms: liquid (pPCM) and microcapsules (mPCM). The volume change, mechanical properties, thermal properties, and microstructure of the improved soil were studied. These results showed that PCMs can release considerable thermal energy during phase transitions, which improves the thermal stability of the soil. The pPCM enhanced the plasticity of soil and prevented brittle failure; mPCM reduced the damage to the soil microstructure caused by freeze–thaw cycles. Macroscopically, it weakened the swell–shrink behavior and limited the degradation of the resilient modulus, unconfined compressive strength, and failure strain of expansive soil. The optimal PCM content was determined based on the mechanical and thermal properties of the improved soil. This study provides a new idea for the engineering treatment of expansive soil in cold regions.

Cyclic swell shrink behaviour of lime and lignosulphonate amended expansive soil—An experimental quantification and comparison

The behaviour of expansive soils is majorly influenced by the mineralogy and the environmental conditions contributed by the seasonal moisture changes. Many structures found on the expansive soil depict severe distress due to the volume change behaviour of the soil. The volume changes correspond to moisture fluctuations which occur with the wetting–drying cycles associated with climatic variations. The wetting–drying​ cycles also impact the chemical treatment methods adopted to curtail swelling and shrinkage. The present study evaluates and compares the magnitude of swelling and shrinkage depicted by Lime and Lignosulphonate amended soils under wetting and drying cycles imposed under laboratory conditions. A specially modified oedometer apparatus was adopted to simulate the field drying conditions. The untreated soil exhibits higher swelling strain than the shrinkage strains with cycles of wetting and drying. There is a decrease of nearly 9% in swelling and 5% in shrinkage from the first cycle to steady state cycle. The swelling strain followed a decline to the steady state, however lime and LS amended soil depicted an initial decrease and then an increase in swelling strains before steady state. The treated and untreated soils also attain equilibrium characterized by different bandwidths and also exhibit difference in swelling and shrinkage rates, with untreated soil exhibiting a longer time to complete the swell-shrink cycles. The study further quantifies these variations for treated and untreated soil and the respective rates of primary and secondary swelling and shrinkage. The results are also justified with a physicochemical analysis of the leachate collected during the wetting–drying cycles.

Influence of Saline Pore Fluid on Soil Behavior during Evaporation

Saline conditions govern soil behavior during evaporation, thereby affecting the water budget in semi-arid regions. This research examined the effects of saline pore fluid on soil behavior during evaporation. The results indicated volumetric reductions of about 5% for silty sand and about 15% for lean clay. The evaporative flux for silty sand decreased from 26 mg/m2∙s to 22 mg/m2∙s in StageII, remained at a constant flux in StageIII, and decreased to 13 mg/m2∙s in StageIV. The air entry and residual suction values were found to be 5 kPa and 100 kPa, respectively, and the total suction of about 5000 kPa merged with matric suction near the Stage II/Stage III boundary. The swell–shrink curve (SSC) was J-shaped with the only void ratio decrease in Stage II. In contrast, the evaporative flux for lean clay decreased from 30 mg/m2∙s to 15 mg/m2∙s in StageII, to 10 mg/m2∙s in StageIII, and then to 5 mg/m2∙s in StageIV. The air entry and residual suction values were 5 kPa and 2000 kPa, respectively, and the total suction during Stage II and Stage III ranged from 1000 kPa to 6000 kPa, with an average value of 3500 kPa. The SSC showed a major void ratio decrease in Stage II, marginal decrease in Stage III, and no decrease in Stage IV. Under high demand, the evaporative flux for silty sand was constant at 180 mg/m2∙s in StageIII and decreased to 50 mg/m2∙s in Stage IV, whereas it decreased for the lean clay from 230 mg/m2∙s to 145 mg/m2∙s in StageII, to 95 mg/m2∙s in StageIII, and then to 25 mg/m2∙s in StageIV. For both soils, the total water loss was found to be six times higher than that under low demand.

Effect of biochar on desiccation of marine soils under constant and cyclic temperatures

Biochar has recently been gaining increasing attention as a stable and sustainable soil amendment material. However, the effect of biochar amendment on the desiccation behaviour of coastal soils has not yet been examined. Consequently, the present study primarily investigated the effect of exposing biochar-amended marine soil (BAS) to constant and cyclic temperatures on its swell–shrink, evaporation and desiccation cracking characteristics. Biochar contents of 1%, 2%, 4% and particle size ranges of PS-1 (600 μm < D ≤ 2000 μm), PS-2 (300 μm < D ≤ 600 μm), PS-3 (D ≤ 75 μm) (D: biochar particle diameter) were employed. It was revealed that the absolute volumetric shrinkage of both unamended and biochar-amended specimens increased as the number of thermal cycles increased. Under continuous heat exposure, 4% (PS-3) BAS in compacted state achieved the maximum reduction in volumetric shrinkage which was 42%. Moreover, under continuous heat exposure, 2% (PS-1) BAS in slurry state achieved the highest reduction in desiccation cracking, which was 73%. The present study highlights the importance of identifying the most effective combination of biochar content and particle size required to achieve a desired outcome, in order to gain the maximum benefit of biochar as an amendment material at the lowest possible cost.

Improvement of Geo-engineering Properties of Expansive Clayey Soil by using Sodium Chloride and Bagasse Ash

Expansive soils contain minerals such as smectite clays that are capable of absorbing water accompanied by shrink and swell behavior and thus change in volume. The swell–shrink behavior of these soils could lead to instability of the structures found on them, specifically the light-weight structures and pavements. Expansive clay soil is encountered in most parts of Egypt. A comprehensive study was made in Sixth of October city to investigate the impact of lime sludge and bagasse ash as an industrial solid waste from sugar-cane factory and sodium chloride salt on geotechnical engineering properties of expansive soil. The macrostructural properties are quantified through laboratory testing for Free swell index, Plasticity index and infiltration tests. The microstructural aspects of the treated soil are observed through X-ray diffraction studies and SEM micrographs. The laboratory results showed that by increasing the lime sludge, Bagasse ash and NaCl concentrations the liquid limit decreased from 100% to 60% while the plastic limit increased from 100% to 90% respectively. In addition, the infiltration tests showed an increase in the infiltration rate from 10% to 80% when LS and Bagasse ash were added to the soil also the free swell decreased from 100% to 70 % sufficiently. XRD patterns showed the formation of new kaolin cementitious compound as the change of montmorillonite to kaolinite mineral took place due to the reaction of high amount of calcium ions produced from the stabilizer, the cation exchange took place between the calcium cation of the lime associated with the surfaces of the clay particles. The effect of cation exchange and attraction causes clay particles to became close to each other, this process is called flocculation which is accompanied by a series of pozzolanic reactions resulting in the formation of clay aggregates that are bound together by the new cementitious products such as calcium aluminate. Scanning Electron Microscopic images (SEM) and SEM micrographs determined the formation of organized dense clay matrices of aggregations that showed the reduction of Montmorillonite clay mineral peak intensities and an increase in kaolinite clay mineral peak intensities due to the change of expansive soil texture and reduction of interplanar spacing of the treated soil.

Evaluation of Geopolymer for Stabilization of Sulfate-Rich Expansive Soils for Supporting Pavement Infrastructure

Stabilization of sulfate-rich expansive subgrade soils is a persistent cause of concern for transportation infrastructure engineers and practitioners. The application of traditional calcium-based stabilizers is generally not recommended for treating such soils because of the formation of deleterious reaction products such as ettringite. Sulfate-induced heaving causes severe structural damage to pavements and accounts for enormous expenditure from routine maintenance and rehabilitation activities. A research study was undertaken to evaluate the feasibility of using a metakaolin-based geopolymer (GP) for the treatment of sulfate-rich expansive soil. Laboratory studies were conducted on natural soil and artificially sulfate-rich soils, when treated with either lime or GP, to evaluate and compare the improvements in the engineering properties, including unconfined compressive strength, swelling and shrinkage, and resilient moduli characteristics over different curing periods. Microstructural studies, such as field emission scanning electron microscopy and X-ray diffraction, were performed on treated soils to detect the formation of reaction products. The engineering studies indicate that GP treatment enhanced strength and resilient moduli while suppressing ettringite formation and the associated swell–shrink potential of the treated soils. The microstructural studies showed that GP gels contribute to the improvement of these engineering properties through the formation of a uniform geopolymer matrix. In addition, the absence of a calcium source suppressed the formation of ettringite in the GP-treated soils. Overall, the findings indicate that GPs could be used as a potential alternative to existing traditional stabilizers for treating sulfate-rich expansive soils.

Bond Behavior of Deformed Bamboo (Bambusa vulgaris) Embedded in Fly Ash Geopolymer Concrete

As the fastest growing plant with high tensile strength, bamboo provides an excellent alternative material to replace steel reinforcement in a concrete structure. However, the bond of bamboo embedded in concrete is very poor due to its surface properties and swell–shrink behaviors, especially when embedded in ordinary Portland cement concrete (OPCC). Thus, this paper presents the experimental investigation on the bond performance of deformed and undeformed bamboo species of Bambusa vulgaris strips embedded in fly ash geopolymer concrete (FAGC). Undeformed bamboo strips with and without nodes were compared to deformed bamboo strips in a corrugated and Galvanized Iron (G.I) rolled wired form in the pull-out test to study the mechanical interlocking effect on the bond performance of bamboo strips embedded in concrete. The groove on the corrugated bamboo strip was made using a router machine, while the wired bamboo was produced by wrapping the G.I wire along the bamboo strip. The difference in groove and wire spacing of the deformed bamboo strip on the bond strength was also observed. The result showed that the geometry of the bamboo strip had a significant effect on the bond performance, with the deformed bamboo strip outperforming the undeformed bamboo strip. In addition, the utilization of FAGC could also reduce the moisture absorption by the bamboo strip. Thus, these results showed that using bamboo strips in FAGC is feasible, contributing to a promising approach for full utilization of bamboo and industrial waste products such as fly ash as construction materials.

Experimental Study on Microstructure Evolution and Fractal Features of Expansive Soil Improved by MICP Method

Experimental study on one-dimensional consolidation and scanning electron microscope imaging of expansive soil improved by MICP method has been carried out, by using WG type consolidator and electron scanning microscope. Theoretical analysis on microstructure evolution process of improved expansive soil has been carried out based on fractal theory and damage theory. Through the research, the influence mechanism of cementation and filling effect of calcium carbonate precipitation on the microstructure of improved soil samples such as particle size and pore characteristics is revealed. Based on fractal theory, a porosity calculation model of improved expansive soil has been established considering microstructure damage of soil. Furthermore, a fractal calculation theory of consolidation deformation of improved expansive soil has been proposed. The relevant calculation parameters have also been determined. The rationality of this calculation theory is verified by comparing the calculated results with the tested results. With these research results, a theoretical foundation for further research on microstructure evolution of expansive soil improved by MICP method has been laid. A new train of thought for quantitative research on the water stability and swell–shrink characteristics as well as strength characteristics of improved expansive soil has been provided.

Swell–shrink behaviour of fly ash-stabilised expansive soils

Class C fly ash, a byproduct of thermal power plants, is often preferred for the stabilisation of expansive soils. However, improper optimisation of the stabiliser may lead to the premature failure of treated soils during wet–dry cycles. This study demonstrates the volume change behaviour of fly ash-stabilised expansive soils subjected to wet–dry cycles. Furthermore, the effect of class C fly ash and lime–class C fly ash on the physical and engineering properties is also studied. The experimental results showed that addition of 20% fly ash to the expansive soil reduced the swell potential to 0% from an untreated swell value of 10.5%. However, when it was subjected to five wet–dry cycles, the initial cementitious effect of the fly ash on controlling the swell was partially lost, and therefore the volumetric deformation of the stabilised expansive soil increased from 0 to 14.5%. Furthermore, among the different additive combinations used for the treatment of expansive soils, it was observed that the combination of 4% lime and 20% fly ash resulted in the volumetric deformation of only 2.05% even after the fifth wet–dry cycle. Besides, the percentage of desiccation cracks has also reduced significantly from 29 to 0.5%.

Intermittent swelling and shrinkage of a highly expansive soil treated with polyacrylamide

This laboratory study examines the potential use of an anionic polyacrylamide (PAM)-based material as an environmentally sustainable additive for the stabilization of an expansive soil from South Australia. The experimental program consisted of consistency limits, sediment volume, compaction and oedometer cyclic swell–shrink tests, performed using distilled water and four different PAM-to-water solutions of P D = 0.1 g/L, 0.2 g/L, 0.4 g/L and 0.6 g/L as the mixing liquids. Overall, the relative swelling and shrinkage strains were found to decrease with increasing number of applied swell–shrink cycles, with an ‘elastic equilibrium’ condition achieved on the conclusion of four cycles. The propensity for swelling/shrinkage potential reduction (for any given cycle) was found to be in favor of increasing the PAM dosage up to P D = 0.2 g/L, beyond which the excess PAM molecules self-associate as aggregates, thereby functioning as a lubricant instead of a flocculant; this critical dosage was termed ‘maximum flocculation dosage’ (MFD). The MFD assertion was discussed and validated using the consistency limits and sediment volume properties, both exhibiting only marginal variations beyond the identified MFD of P D = 0.2 g/L. The accumulated axial strain progressively transitioned from ‘expansive’ for the unamended soil to an ideal ‘neutral’ state at the MFD, while higher dosages demonstrated undesirable ‘contractive’ states.

Investigating characteristics of expansive soil of Rajkot modified with flyash and nanolime

Rajkot, Gujarat's westernmost city, has a severe problem with expansive soils. Nanotechnology now has the ability to significantly alter the physical and chemical properties of materials by introducing only a small amount of nanomaterials. Given the enormous potential of nanomaterials, nanolime in combination with class-F flyash was used in this work to try to stabilise the soil. To begin, nanolime is made using a wet chemical technique. Second, Suyog suppliers in Ankleshwar provides commercially available class-F flyash. Various combinations of these two elements were explored to investigate the effect of putting these two components in the expansive soil of Rajkot city. Finally, to control swell–shrink behaviour, the optimal dose of these two mixes was studied. The dosage of class-F flyash used is 20 to 60 percent by dry mass of the expansive soil, with a steady increase of 20 percent. Furthermore, nanolime dose is 0.5 and 1 percent by mass of Rajkot's expansive soil. The samples were made by dry combining the aforesaid materials, soaking them in water, and allowing them to mature for 3 to 28 days. The impacts of stabilisation were investigated using soil metrics with expansive features such as atterberg's limits, free swell index, and swell pressure. It was discovered that using 1% nanolime in combination with 40–60 percent class-F flyash can reduce plasticity by 70 percent, swell pressure by 95 percent, and increase shrinkage limit by 60 percent making free swell index zero. As a result, nanolime combined with class-F flyash is successful in converting expansive Rajkot soil to non-swelling soil.

Effect of Synthetic Geotextile on Stabilization of Expansive Subgrades: Experimental Study

Structures constructed on expansive soils experience higher upward pressure due to their swelling characteristics. Various conventional treatment methods developed to counteract swell–shrink characteristics of expansive soil are deemed time consuming and not feasible for use in pavement. Geotextiles (GTs) have been used as a filtration and separation medium; however, their effect on swell pressure and shear strength of expansive soil has not been well explored. This study aimed to address these issues by using GT to control swelling behavior, drain moisture content, and provide support at the soil interface. Swell pressure and shear strength were quantified by constant volume swell pressure and direct shear and unconfined compressive strength tests, respectively. The influence of single-layer, double-layer, and triple-layer GTs at varying depths was studied. The higher tensile strength of the GT layer restrained the swell pressure mobilized by resisting internal soil movements and facilitating in-plane drainage conditions. Additionally, soil–geotextile interfacial interactions were observed to contribute to improvement in shear strength. Comprehensive statistical analysis using one-way analysis of variance (ANOVA) was carried out on swell and strength properties. The present study ascertained the use of GT for the dual function (i.e., strength and swell control) of stabilizing expansive subgrades.

Hydraulic and Swell–Shrink Characteristics of Clay and Recycled Zeolite Mixtures for Liner Construction in Sustainable Waste Landfill

This paper presents research considering hydraulic as well as swelling and shrinkage characteristics of potential recycled fine particle materials for compacted clay liner for sustainable landfills. Five locally available clay soils mixed with 10% (by mass) of NaP1 recycled zeolite were tested. The performed analysis was based on determined plasticity, cation exchange capacity, coefficient of saturated hydraulic conductivity after compaction, several shrinkage and swelling characteristics as well as, finally, saturated hydraulic conductivity after three cycles of drying and rewetting of tested specimens and the reference samples. The obtained results showed that addition of zeolite to clay soils allowed reduction in their saturated hydraulic conductivity to meet the required threshold (≤1 × 10−9 m/s) of sealing capabilities for compacted clay liner. On the other hand, an increase in plasticity, swelling, and in several cases in shrinkage, of the clay–zeolite mixture was observed. Finally, none of the tested mixtures was able to sustain its sealing capabilities after three cycles of drying and rewetting. Thus, the studied clayey soils mixed with sustainable recycled zeolite were assessed as promising materials for compacted liner construction. However, the liner should be operated carefully to avoid extensive dissication and cracking.

Forensic Analyses and Rehabilitation of a Failed Highway Embankment Slope in Texas

A comprehensive investigation was designed and conducted to identify the potential causes of failure of a highway embankment slope in Texas and evaluate the effectiveness of lime treatment to rehabilitate the failed slope. Highway slopes built with high plasticity clays often experience shallow slope failures after exposure to repeated wet–dry weathering cycles. Lime stabilization generally reduces the swell–shrink potential, enhances the engineering properties of problematic clayey soils, and can potentially prevent surficial slope failures. However, exposure to wet–dry cycles can negate some of the benefits of lime treatment and therefore a study was conducted to address the use of this lime treatment to stabilize embankment slopes. Extensive laboratory tests were conducted to study the effect of weathering cycles on the degradation of hydro-mechanical properties of untreated and lime-treated soils. Rainfall-induced slope stability analyses were performed to investigate the probable causes of slope failure and evaluate the stability of lime-treated surficial slope. The optimum stabilizer dosage and treated layer thickness required for the slope rehabilitation were determined based on laboratory tests and numerical analysis results. The stability analysis results indicate that the degradation of surficial soil’s hydro-mechanical properties and the development of a perched water table during prolonged rainfall possibly caused the slope failure. The post-treatment increase in shear strength properties, reduction in moisture fluctuations recorded by embedded moisture sensors, and the presence of newly installed underlying drains are expected to prevent recurrence of surficial slope failures. Salient results from this study are covered in this paper.