Sand Stabilization Research Articles

Rice husk ash-carbide lime as an alternative binder for waste foundry sand stabilization.

Rice husk ash (RHA) is an excellent pozzolana and associated with hydrated lime (HL), it becomes an alternative binder to Portland cement in soil stabilization. In the context of waste valorization, waste foundry sand (WFS) and carbide lime (CL) have been investigated in civil construction and environmental geotechnical applications. However, stabilizing WFS with alternative binders to Portland cement represents a large field of research to be explored. This study evaluated the stabilization of WFS with a binder based on RHA and CL, compared to the use of RHA-HL. An experimental design was carried out to evaluate the influence of different dry-specific weights (12.00, 12.75, and 13.50 kN/m3), RHA contents (10%, 20%, and 30%), and curing times (28, 60, and 90days) under unconfined compressive strength (UCS). UCS results were submitted to statistical analysis and correlated to the porosity/binder content index (η/Biv). Healing capacity, mineralogy, microstructure, and leaching of metals from mixtures of interest were evaluated. The results showed that higher specific weights and higher percentages of RHA promoted better strength. The η/Biv0.28 index proved to be an adequate parameter to assess the UCS of WFS-RHA mixtures with different limes (CL and HL), lower porosity, and higher binder content leading to higher strengths. The mixture's mineralogy and microscopy showed the formation of cementing gels, corroborating the strength gains. WFS stabilized with both binders (RHA-CL and RHA-HL) presented satisfactory environmental performance, allowing the immobilization of metals in the waste compositions.

THE STABILIZED DUNES: A PILOT STUDY ON THE EFFECT OF ACACIA TORTILIS ON GROUND VEGETATION, FROM THAR DESERT, INDIA

In modern days, sand dune stabilization works are very common in desert areas globally. The purpose is multifaceted; developmental needs, soil moisture conservation works, and prevention of desert spread being the main among them. In the Indian state of Rajasthan, the same works have been ongoing for a long in the Thar desert, primarily by the forest department. This study was aimed as a non replicated administrative study, which has reflected on the possible correlation between the stabilization work by afforestation and gradual loss of native shrub species of desert ecosystem as found from the pilot sites. The preliminary findings of this study were then verified against previous research and findings in other arid regions of the world. Simple counting of standing tree and shrub species was done from 1 sq. m. sample plots of both forest department plantation sites and non-forest land areas. It was found that area with matured grown Acacia tortilis has less ground coverage than other areas. Arid ecosystem has unique survival adaptations, the fast growth of an introduced foreign species impacting the native ground cover can be due to multiple ecological reasons. A much broader replicated study is necessary to ascertain this fact and thereby take necessary measures for preserving both the desert ecosystem and enhance the sand stabilization works

Sex-Related Ecophysiological Responses of Hippophae rhamnoide Saplings to Simulate Sand Burial Treatment in Desertification Areas

(1) Background: In recent years, Hippophae rhamnoides has been used extensively to prevent desertification in China due to its nitrogen (N) fixation and sand stabilization abilities. However, as a dioecious species, few studies have focused on the sexual dimorphism of H. rhamnoides in response to sand burial, which frequently presents in desertification areas. (2) Methods: In this paper, we explored the ecophysiological responses of female and male saplings of H. rhamnoides under unburied treatment (control) and different sand burial depths (denoted as T33, T67, T90 and T133, corresponding to sand burial depths of 33, 67, 90 and 133 percent of the mean initial height of the saplings, respectively). (3) Results: Compared with unburied controls, the T33 treatment significantly promoted biomass accumulation and photosynthetic capacity, whereas T67 and T90 treatments inhibited biomass and physiological parameters of the two sexes. Deeper sand burial treatments, i.e., T90 and T133, significantly decreased the survival rates of the two sexes. Furthermore, the sex-specific responses of the two sexes of H. rhamnoides were affected by different depths of sand burial. Males had higher levels of stem starch and root sucrose and exhibited a larger increase in root nodule biomass under the T33 treatment, indicating better carbohydrate utilization and N fixation, whereas females showed lower total biomass and fewer root nodules, as well as more inhibition of photosynthetic and chlorophyll fluorescence parameters, water potential and root carbohydrates, indicating more negative effects on females than males under the T67 treatment. (4) Conclusions: We conclude that sex-related response and adaptation to sand burial depths may potentially affect the colonization, sex ratio and ecological function of the two sexes of H. rhamnoides in desertification areas.

Study on the Safety Analysis of Dredger Fill Sea Sand Reused in Embankment Slope near the Yangtze River

In view of the shortage of sand and gravel aggregates, the sea sand in coastal areas is used as roadbed filler in road restoration of tunnel project by the Yangtze river. The basic mechanical performance tests were carried out to demonstrate the particle gradation and consistency limit of dredger fill sea sand. Triaxial test and direct shear test were performed to analyze the stress-strain relationship of sea sand shear strength in riverside environment and the law of shear displacement under vertical pressure. The road performance was analyzed by testing the compaction characteristics and deformation resistance of dredger fill sea sand. The riverside slope is always damaged by water flow, therefore, the stability of the dredger fill sea sand road slope under the measures of wrapping soil was analyzed. Based on the analysis of existing measures to improve the safety of sea sand used in road, the technology of sea sand solidified by alkaline coupling agent is proposed.

Recycling and Utilization Assessment of Municipal Solid Waste Materials to Stabilize Aeolian Sand

Municipal solid waste management is a global concern due to the growth rate of population and urbanization. This paper aims to determine the possibility of utilization of municipal solid wastes such as fired clay brick powder (FCBP), eggshell powder (ESP), and recycled glass powder (RGP) for the stabilization of aeolian sand. Using such green binders can eliminate the perils associated with inappropriate waste disposal. Different combinations of FCBP, ESP, and RGP were added to the soil, and two activators (KOH and NaOH) were used to study the effects on its engineering and chemical properties. The effects of various parameters were investigated based on unconfined compression strength tests (UCS), pH tests, and scanning electron microscopy (SEM) tests. The results revealed that using all of these three precursors leads to the co-existence of calcium silicate hydrate (C-S-H) gel with the geopolymeric gel (N-A-S-H) and provides the highest UCS value. According to the obtained results, NaOH had a better ability to dissolve the precursors' particles than KOH, resulting in better polymerization. The optimum composites found in the research had a 91-day UCS of 5.32 MPa, which are suitable for the base material in pavement construction.

Biodegradable Interpolycomplexes for Anti-Erosion Stabilization of Soil and Sand.

A linear anionic polysaccharide, sodium alginate, electrostatically interacts with a cationic polysaccharide, quaternized hydroxyethyl cellulose ethoxylate, in aqueous solution, thus giving an interpolyelectrolyte complex. Aqueous solutions of the initial polysaccharides and polycomplexes with an excess of the cationic or anionic polymers were used for the stabilization of soil and sand against water erosion. Physicochemical, mechanical and biological properties of the polymers and coatings were characterized by gravimetric analysis, viscosimetry, mechanical strength assessment, cell viability, and cell-mediated degradation with the following main conclusions. (a) Non-stoichiometric polycomplexes with an excess of cationic or anionic units ("cationic" and "anionic" polycomplexes, respectively) form transparent solutions or stable-in-time dispersions. (b) The complexation results in a decrease in the viscosity of polymer solutions. (c) A complete dissociation of polycomplexes to the initial components is achieved in a 0.2 M NaCl solution. (d) Soil/sand treatment with 1 wt% aqueous solutions of polymers or polycomplexes and further drying lead to the formation of strong composite coatings from polymer(s) and soil/sand particles. (e) Cationic polycomplexes form stronger coatings in comparison with anionic polycomplexes. (f) The polymer-soil coatings are stable towards re-watering, while the polymer-sand coatings show a much lower resistance to water. (g) The individual polysaccharides demonstrate a negligible toxicity to Gram-negative and Gram-positive bacteria and yeast. (h) The addition of Bacillus subtilis culture initiates the degradation of the polysaccharides and polycomplexes. (i) Films from polysaccharides and polycomplexes decompose down to small fragments after being in soil for 6 weeks. The results of the work are of importance for constructing water-resistant, low toxicity and biodegradable protective coatings for soil and sand.

Stabilization of Sandy Soils by Bentonite Clay Slurry at Laboratory Bench and Pilot Scales

Sand is one of the most abundant, naturally occurring materials in many parts of the world, which is used in local rural areas in infrastructure projects such as in the construction of low volume paved and unpaved road layers due to their availability at low cost and scarcity of other suitable construction materials. Several geotechnical solutions for sand stabilization have been undertaken to improve their properties in order to overcome erosion, failure of pavements under traffic loading, embankments, cuts and excavations caused by failures of sand structure. In this investigation, bentonite clay–water slurry was used due to its cohesive and eco-friendly nature to improve sand strength by the means of manual injection in the laboratory and pilot scales. Sand was stabilized using variation of bentonite clay contents, 0%, 1%, 2%, 3%, and 4% (by weight of dry sand), at different curing times: 0 days, 1 day, 2 days, and 3 days. Direct shear tests were conducted to determine shear strength parameters for sand before and after stabilization process. Furthermore, a transparent polypropylene box (60 cm × 40 cm × 30 cm) was used in this study as a larger scale for sand stabilization technique by applying manual grouting of bentonite clay–water slurry to the sand mass. A mechanical shaker was used at 100, 200, 300, and 400 rpm for 10 min at each stage to test the stability of sand in addition to using a Scanning Electron Microscope (SEM) to obtain images for stabilized sand and Ground Penetrating Radar (GPR) to scan soil mass before and after stabilization. The test results showed that a slurry composed of 3% of bentonite clay additive with 10.3% added water by weight of dry sand mass are the optimum amounts for the stabilization process, which provides a substantial resistance to shear forces.

Mechanical stabilization of aeolian sand with ceramic brick waste aggregates

The use of ceramic brick waste is a sustainable and eco-friendly alternative for the stabilization of soils in comparison with other more traditional additives, such as cement. The addition of different types of construction wastes to soils has been so far mainly investigated for cementitious materials rather than for earthworks projects and civil infrastructures, and even less for aeolian sand. In this research, ceramic brick waste aggregates have been experimentally studied as an option to improve the geotechnical properties of aeolian sand from Jeddah (Saudi Arabia). Three different percentages of replacement have been considered, 15 %, 30 % and 45 %, since such high replacements have not been investigated in the literature. This research is focused on employing aeolian sand for earthworks applications. The experimental program is based on size analysis, compaction and California Bearing Ratio (CBR) tests specially modified to manage the represent different lateral confinement in the samples, and the results are confirmed by scanning electron microscope (SEM). Experimental results demonstrate an improvement of the overall geotechnical properties of the aeolian sand after mixing it with ceramic brick waste aggregates by means of the correction of the missing particle fractions and the addition of more aggregated particles, improving the coefficient of uniformity (Cu) from 2.37 (aeolian sand) up to 3.56 (45 %-brick waste). The CBR obtained for the two higher replacements is around 33 % in confined conditions (triple than aeolian sand) and almost 1 % for unconfined conditions independently of the replacement. An optimal replacement of 30 % has been identified and the possible crushing and breakage of the waste aggregates are discarded. This mechanical stabilization can be considered feasible and environmentally suitable.

Sand control effect of HDPE sandbreak nets with different porosity structure

Straw checkerboard sand barriers with a porous structure that consists of a pervious upper portion and a dense lower portion are widely used to achieve great sand control effect. Considering this, and resolving the serious earth surface undercutting problem after HDPE sandbreak net checkboard barriers setting, the authors used HDPE (high-density polyethylene) materials to prepare new sandbreak materials with a similar porous structure. Through wind tunnel simulations and field sand control monitoring, we compared the sand control effect of three HDPE sandbreak nets with different porosity structure. Compared to the sandbreak net with uniform porosity structure, the three types of HDPE sandbreak nets with different porosity structure had poorer effect on reducing sand transport rates, but had longer effective protection distance before sandbreak nets at low wind velocity conditions (<12 m/s), longer effective protection distance at high wind velocity (>14 m/s) and longer effective protection distance between sandbreak nets at all experimental wind velocity conditions. Wind and sand control effect characteristics of HDPE sandbreak nets with different porosity structure provide an ideal material on semi-buried checkerboard sand barriers for sand stabilization. By contrast, uniform-type sandbreak nets are used as materials on high upright sand fences for sand blocking. These HDPE sandbreak nets can be used to replace traditional sandbreak materials and have a very high potential for widespread and popular application in aeolian sand disaster control.

Field Test on Soybean-Urease Induced Calcite Precipitation (SICP) for Desert Sand Stabilization against the Wind-Induced Erosion

Soybean-urease induced calcite precipitation (SICP) is an effective method for the improvement of sand, which forms a biocemented layer on the desert sand surface to resist erosion induced by the wind. Under this study, field tests were carried out to determine how the SICP approach may enhance the resistance of the desert to wind-induced erosion and the durability of SICP treatment in southeastern margin of Tengger Desert, Ningxia Hui Autonomous Region, China. The experimental results demonstrated that the erosion resistance of desert sand was significantly enhanced due to the SICP treatment, and the improvement effect was enhanced with the increase of the biocement solution concentration and dosage and the number of treatment cycles. Furthermore, it was also found that the resistance of SICP-treated sand to erosion induced by the wind reduced as the development of time reduced. Based on the test results in this paper, larger biocement solution concentration and dosage and multiple treatment cycles are proposed in the areas where severe wind-induced erosion takes place in order to improve the ductility of SICP treatment.

Warmer Temperature and Spatiotemporal Dynamics during Primary Succession on Tropical Coastal Dunes.

Coastal dunes are sensitive indicators of climate change: it is expected that higher precipitation and warmer temperature will promote vegetation growth and sand stabilization. Alternatively, dunes may become active during severe droughts, which would reduce plant cover and increase sand mobility. Consequently, it is relevant to explore community shifts and self-organization processes to better understand how coastal dunes vegetation will respond to these projected changes. Primary succession allows the exploration of community assembly and reorganization processes. We focused on three environmental variables (bare sand, temperature, and precipitation) and five successional groups (facilitators, colonizers, sand binders, nucleators, and competitors). For 25 years (from 1991 to 2016), species turnover was monitored in 150 permanent plots (4 × 4 m) placed on an initially mobile dune system located on the coast of the Gulf of Mexico. The spatiotemporal dynamics observed during primary succession were consistent with the facilitation nucleation model. As late colonizers grew and expanded, psammophytes became locally extinct. The spatial patterns revealed that ecological succession did not occur evenly on the dunes. In addition, the increased mean yearly temperature during the last decades seemed to be associated with the accelerated increment in plant cover and species richness, which had not been registered before in Mexico.

The response of authors to the comment on “a new approach to stabilization of calcareous dune sand” [Int. J. Environ. Sci. Technol. 19, 3581–3592 (2022)

The response of authors to the comment on “a new approach to stabilization of calcareous dune sand” [Int. J. Environ. Sci. Technol. 19, 3581–3592 (2022)

Self-aggregating behavior of poly(4-vinyl pyridine) and the potential in mitigating sand production based on π-π stacking interaction

Unconsolidated sandstone reservoirs are most susceptible to sand production that leads to a dramatic oil production decline. In this study, the poly(4-vinyl pyridine) (P 4 VP) incorporated with self-aggregating behavior was proposed for sand migration control. The P 4 VP could aggregate sand grains spontaneously through π-π stacking interactions to withstand the drag forces sufficiently. The influential factors on the self-aggregating behavior of the P 4 VP were evaluated by adhesion force test. The adsorption as well as desorption behavior of P 4 VP on sand grains was characterized by scanning electron microscopy and adhesion force test at different pH conditions. The result indicated that the pH altered the forms of surface silanol groups on sand grains, which in turn affected the adsorption process of P 4 VP. The spontaneous dimerization of P 4 VP molecules resulting from the π-π stacking interaction was demonstrated by reduced density gradient analysis, which contributed to the self-aggregating behavior and the thermally reversible characteristic of the P 4 VP. Dynamic sand stabilization test revealed that the P 4 VP showed wide pH and temperature ranges of application. The production of sands can be mitigated effectively at 20−130 °C within the pH range of 4–8.

Mapping of aeolian deposits of an industrial site in the arid region using the TIR bands of ASTER and study of physicochemical characters and stabilization of sand erosion

This study describes the spectral emissive character of silicate and carbonate minerals of aeolian deposits and maps the deposits and sand encroachments that occurred in and around the site 5/6 of Qatar Fertilizer Company (QAFCO), Qatar using thermal infrared (TIR) bands of ASTER. The results of studies show that the quartz and unaltered silicates have spectral features between 8.12 and 9.27 µm, and the calcite and dolomite have emissivity minima near 11.4 and 11.2 µm, respectively. The mapping of deposits, dunes, and carbonate formations using the bands, and quartz index (QI), and carbonate index (CI) displayed their occurrence, distribution, and direction of sand movement from NW to SE. The sand encroachment was mapped using high spatial resolution satellite data of WorldView-2. The study of physicochemical characteristics of field samples showed the occurrence of sand grains up to 99.81% and the XRD and geochemical analyses represented the presence of quartz, calcite, dolomite, albite, and halite minerals in the deposits. In addition, the bacterial strains isolated from the samples indicated high urease activity leading to precipitation of carbonate minerals via microbially induced calcite precipitation (MICP) processes, and demonstrated high potential for utilization for sand stabilization of the QAFCO site.

Microbially Induced Calcite Precipitation (MICP) for Stabilization of Desert Sand against the Wind-induced Erosion: A Parametric Study

Biocementation, based on microbially induced calcite precipitation (MICP), is a novel soil improvement method, which can form a cemented layer on the surface of desert sand to resist wind-induced erosion. In this work, the surface penetration resistance test and wind tunnel test were conducted to evaluate the various influential factors for the resistance of biocemented desert sand to wind-induced erosion, including the treatment factors, such as treatment temperature and biocement solution concentration, and durability factors such as the development of time, freezing–thawing cycles, and drying–wetting cycles. The test results demonstrated that the erosion resistance of biocemented desert sand was improved by the increase of treatment temperature and the concentration of biocement solution, which was manifested in the increase of surface penetration resistance of biocemented samples. In addition, the resistance of biocemented desert sand to wind-induced erosion decreased with the increased number of drying–wetting cycles, to lesser extents, with the development of time and the increased number of freezing–thawing cycles.

Geotechnical characterization of sustainable geopolymer improved soil

Abstract Geopolymer (GP) has recently emerged as a novel and environmental friendly alternative to conventional soil stabilization products like lime and Ordinary Portland Cement (OPC), which adversely affect the environment. This article emphasizes GPs produced from high calcium class C fly ash (CFA) and an alkali activator comprising sodium hydroxide and sodium silicate solution for sand stabilization. The experimental program includes a series of unconfined compressive strength (UCS), flexural strength, tensile strength, and microstructural analyses using scanning electron microscopy. Results revealed that UCS, flexural strength, and tensile strength of GP-treated soil were in the range of 2–10, 0.5–2.0, and 0.4–1.2 MPa, respectively (depending on the ratio of fly ash and activator). These strengths were even higher than those of cement-stabilized soil. The microstructural analysis revealed that the formation of dense calcium–sodium alumina–silicate hydrated gel (C, N–A–S–H) is the reason for strength improvement. According to the findings of this study, using a CFA-GP binder for soil improvement is a viable alternative to OPC in geotechnical applications.

Effect of Aeolian Sand Powder Addition on Frost Resistance of Concrete Pavement.

In order to solve the problem of exploring the freeze-thaw characteristics of modified aeolian sand mixed with cement and silt, the authors propose a freeze-thaw cycle test of modified aeolian sand under the condition of mixing 5% cement and silt with different contents. In this experiment, under freeze-thaw conditions, its intensity decay and mass volume change law and the changes of freeze-thaw characteristics were comprehensively characterized by multiple indicators. The result shows that, after two freeze-thaw cycles, the compressive strength and peak strain of the improved aeolian sand were positively correlated with the silt content. With the increase of the number of freeze-thaw cycles, the compressive and antidestruction capacity of the improved aeolian sand with high silt content and low silt content decreased significantly. 15% silt content improves the structural stability of aeolian sand. It is proved that the authors' experiment can intuitively and effectively reflect the change law of soil strength after freezing and thawing of such improved aeolian sandy soil, which has displayed significance.

Enzyme Induced Calcite Precipitation (EICP) for Engineering Application by Using Plant Based Biomaterials

This research investigated the effect of reactant concentrations, reaction medium, urease enzyme source, and calcium source on the precipitation rate of calcium carbonate (CaCO3). This project is aiming to develop a biochemical reaction by using Enzyme Induced Calcite Precipitation (EICP) technique. This new technique would help in replacing the traditional cementation for the dune sand stabilization and promise an environmentally friendly and sustainable approach in the field of construction materials. Jack beans and soybeans were employed as a substrate to catalyze the urea hydrolysis in the study. The sources of calcium used in the experiments were calcium chloride (CaCl2), eggshell and sesame. In addition, both seawater and distilled water were used as a reaction medium to distinguish the effect on calcium carbonate precipitation. The experiments showed that using sesame at a concentration of 4.5 g, 5 g of urea and 6 g of jack bean at 60 mL of distilled water, is the best reaction conditions to precipitate 100.288 g of calcium carbonate. Further, the results indicated that the calcium carbonate precipitation enhanced by using 5 g of urea, 5 g of CaCl2 and 5 g of soybean at 50 mL of seawater. The precipitation amount was 25.593 g. These results provide a useful way for the bio cementation by following the EICP technique to address the issues of environment friendly practice of ground improvement.

Evaluation of Strength Properties of Sand Stabilized with Wood Fly Ash (WFA) and Cement

The article describes the laboratory evaluation of mixtures of sand modified with wood fly ash (WFA) and additionally stabilized with different amounts of cement. Laboratory research includes determining the California Bearing Ratio (CBR), compressive and indirect tensile strengths of the mixtures, and the resistance of mixtures to freezing/thawing cycles. The aim of the research is to determine if WFA, an alternative material, can improve sand bearing capacity and contribute to strength development while reducing necessary cement amounts and satisfying the technical regulation for use in pavement base courses. The test results obtained show that WFA has a considerable stabilization effect on the sand mixture and improves its load bearing capacity. By adding a small quantity of the cement, the hydraulic reaction in the stabilized mixture is more intense and results in greater strengths and an improved resistance to freezing. The test results show that, by replacement of part of the sand with WFA (in the quantity of 30%), greater strengths can be achieved in relation to the mixture of only sand and cement. Additionally, the content of cement necessary for the stabilization of sand (usually 8–12%) is considerably reduced, which enables cost savings in the construction of pavement structures.

A Synthetic Chart for Internal Stability Assessment of Soils Based on Soil PSD Curves

Awareness of granulated soils’ internal instability is an important parameter when designing granulated filters, and the ability of a granulated soil’s internal stability can be verified using the soil PSD (Particle Size Distribution) curves’ secant slopes. The current work presents a new method to calculate the soil PSD curves’ secant slopes automatically, and a synthetic diagram is presented for the potential examination of the granulated soils’ internal stability. To verify the feasibility and accuracy of this synthetic diagram, 80 specimens of soil were investigated in this work and categorized into two groups: 50 sand–gravel soils and 30 (clay)–silt–sand–gravel soils. The obtained conclusions indicate that the internal stability and instability potentials of sand–gravel soils can be distinguished successfully with a synthetic chart and the Kenney and Lau criterion but cannot be assessed with the Kezdi and Sherard criteria. None of the criteria studied here can be used for the internal stability assessment of silt–sand–gravel and clay–silt–sand–gravel soils.