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The expansive soil has serious impact due to its unstable volumetric behaviour when it undergoes seasonal variations. In order to utilise the problematic expansive soil for any kind of work it needs to alter the behaviour of soil by stabilisation using addition of admixtures. From the economical point of view using industrial waste materials is the cost-effective technique. In this work the selection of industrial waste materials which comes from tile manufacturing such as Tile Waste Powder (TWP) and Foundry Sand (FS) outcome of metal casting industries as an admixture. The Tiles Waste Powder has the nature to improve the compaction behaviour of expansive soil because of its high lime content and Foundry sand are used to develop the strength behaviour of problematic soil due to the presence rich silica content. In this paper, untreated soil got treated using the different proportions such as 5,10, 15,20 and 25% of Tile waste powder and their corresponding the compaction and strength characteristics of the soil sample were determined under different curing periods. Also the tests have been conducted for optimum percentage of tile waste mixed along with varying percentage of Foundry Sand (4, 6, 8, 10 and 12%) in soil sample. The results was obtained from the standard proctor test, UCC and CBR test and it further analysis shows that the increasing the proportion of TWP rises the peak strength of the treated soil up to 20% for the maximum 28 days curing. Also, from the result analysis for the combination of FS and TWP by optimum percentage of Tiles Waste Powder (20%) with 12% of Foundry sand shows the increment in the strength characteristics of soil. The TWP and Foundry Sand can be effectively used in stabilization works in order to utilise the waste by effective minimization of disposal problems.

Disposal of waste in municipal solid waste landfills is the only way of waste disposal in Serbia, with daily compaction and covering with soil material. Due to less space for the construction of new landfills, it is necessary to use their maximum capacity. Well-compacted municipal solid waste takes up less volume and enables safer storage, so it is useful to previously determine the compaction parameters in the laboratory: maximum dry unit weight (γdmax) and optimal water content (wopt). In the practice so far, the standard method has been used to obtain these parameters (Proctor compaction test) which is common in soil mechanics. However, although this methodology has been adopted, different treatments of municipal solid waste at the landfill (including pre-treatment) indicate the need to change this classical approach. Therefore, during the research, various innovative solutions are introduced, such as the change of the classic flat Proctor hammer, by adding spikes, whose function, in addition to compaction, is partial destruction and shredding of municipal waste. In this way, the operation of compactors (hedgehogs) in the field is simulated. The paper presents the behaviour of four artificially prepared samples of municipal solid waste of different composition. The samples were tested in the standard Proctor apparatus at the same compaction energy, using different hammers, a standard flat hammer, and an innovative hammer with spikes. After that, the geotechnical effects of compaction depending on the applied approach were analyzed.

Conventional materials are used extensively for construction of road pavements which can one day lead to its’ depletion. Expanded polystyrene (EPS) beads which are lightweight cellular plastic polymeric material is an excellent alternative material along with industrial wastes like fly ash and bottom ash that can be for the construction of flexible road pavements. This study describes the engineering behavior of EPS beads as a geo-material of different combinations with fly ash (FA), bottom ash (BA) and expansive soils (ES). Laboratory tests including compaction test were performed on samples of various proportions of EPS beads of EPS beads + Fly ash (EFA), EPS beads + Bottom ash (EBA), and EPS beads + Expansive soil (EES) to calculate the optimum value of addition of EPS beads to EFA, EBA and EES samples that would provide the highest strength to it. California Bearing Ratio (CBR) value and other strength parameters were calculated for optimal mixes of EFA, EBA and EES samples. Optimum size of EPS beads size was considered as 1 mm. Results of laboratory study suggest that addition of 0.5% EPS beads by weight to fly ash, bottom ash and expansive soil enhances its shear and bearing characteristics. Numerical simulations were carried out on PLAXIS 2D for optimal mixes of EFA, EBA and EES pavement blocks to check its behavior and suitability as a replacement of granular sub-base (GSB) layer materials in flexible pavement. Pavement design charts were also prepared to present a comparison between conventional and EPS composite pavements. The results of numerical analysis suggest that EFA and EBA can replace maximum 21.33% and an average of 12.25% of total thickness of conventional GSB layer. Cost analysis of overall road pavement showed that EFA, EBA and EES can reduce maximum overall costs up to 12.87%, 12.09% and 10.56% respectively when replaced with conventional GSB layer materials of the road pavement.

Soil is only materials which is easily available on the earth and used in many purposes in construction of structure. Soil stabilization varies a great deal and improves the bearing capacity and maintenance. Increased higher resistance values, reduced plasticity, lower permeability, reduced pavement thickness, elimination of excavation, and importing new materials are all advantages of soil stabilization. The Present study has been carried out for stabilization of locally available clayey soil with varying percentages of Fly ash and Jute Fibers. The Characterization of materials is being followed with the sample preparation and mechanical testing such as Standard Proctor Test, Un-confined Compression Testing and California Bearing Ration Test. The Modied Samples have showcase a considerable improvement in the engineering properties of soil. There after conclusion, Practical applications and Future Scope of study concludes the outcomes and suggestion from the study.

An environmental improvement method using albumen, which is convenient, cost-effective, rapid and environmentally friendly, has been used for soil stabilization. In this research, the improvement influence of albumen added in various percentages to loess soil was investigated. Atterberg limits and compaction test were performed to study the influence of albumen on the soil. In addition, oedometer test and compression and extension triaxial tests were conducted to analyze geotechnical characteristics of the soil after treatment. From an engineering perspective, compression and extension strength of soils stabilized with 2% albumen at confining pressure of 200 kPa were 1.47 and 0.122 times larger than that of untreated soils, respectively. In all treated specimens, secant deformation modulus versus albumen content displayed higher values than untreated specimens, it means that deformability of treated specimens is less than untreated soil. In undrained compression test maximum pore water pressure decreased in treating specimens. Also, pore water pressure in extension triaxial test changed from negative to a positive value when treating the specimen with 2% albumen at confining pressure of 200 kPa. Treated specimens are shown more stable structure in comparison with untreated specimens. The behavior of the specimens changed to be more dilative, especially, in treating specimens with 2% albumen. Furthermore, settlement of the treated specimens decreased compared with untreated specimens. Field emission scanning electron microscopy images presented less porous and denser soil structure on the surface of treated specimens. Albumen additive can be implemented as a soil stabilizer in geotechnical projects.

The current study presents the laboratory investigation on the use of nano-silica (0.2, 0.4, 0.8 and 1.0%) and polypropylene fiber (0.25, 0.50, 0.75 and 1.0%) in problematic clayey soil to enhance the shear strength and compaction characteristics. From the Transmission electron microscopy (TEM) analysis, it is observed that the diameter of nano-particles used in this study was in the range of 10–20 nm. The nano-particles have a spherical shape and amorphous in nature. Extensive laboratory tests such as the standard Proctor compaction test and unconfined compressive strength test have been conducted on untreated and polypropylene fiber along with nano-silica treated clayey soil. The outcomes showed that the addition of polypropylene fiber in poor soil, increase the maximum dry density and reduce the optimum moisture content of the soil. Whereas, the addition of nano-silica to the clay soil results in reduced maximum dry density and increased optimum moisture content. Unconfined compressive strength of clay soil is increased with the addition of polypropylene fiber and nano-silica to the clay soil. The optimum dosage of polypropylene fiber and nano-silica added to the poor soil was 0.75% and 0.8%, respectively. The Young’s modulus of clay soil was increased with the addition of polypropylene fiber and nano-silica. The microscopic analysis confirmed that C–S–H gel was the main cementitious product, and the inclusion of nano-silica can contribute to a denser packing of soil particles.

In this research, a geotechnical assessment was conducted for clay of the Gercus Formation to determine its suitability for embankment dams. The selected area is located in the north of Iraq. Six samples were collected from two sites in Dokan (Sulaimaniyah) and Haibat Sultan mountain (Koysinjaq), three samples each. Various geotechnical (physical, mechanical and chemical) tests were conducted based on standard specifications. The results of the grain size test of clay samples showed their conformity with Zone C curves and their suitability for the construction of embankment dams, according to the Iraqi standard for roads and bridges. The results of the plasticity limits test showed that the soil is made of fine, low plasticity silt (ML), and low plasticity clay (CL), according to the unified standard soil classification. The water content and plasticity limit tests (liquid limit, plastic limit, and plasticity index) demonstrated that these clays are conformable with the limits of the Iraqi standards. The results of the modified compaction test found a maximum dry density value of 1.962 g/cm3 with an optimum moisture content of 11.5%. The results of the permeability index (K) revealed low permeability according to the Das classification and, therefore, showed the suitability of the samples as raw filling materials in the construction of dams. Chemical tests (sulfate content, organic materials content, total dissolved salts, gypsum content, and pH value) showed compatibility with the requirements for the use in dams construction under the Iraqi standard (SoRB/ R5).

Many of the damage in road construction occurred because the soil did not have a good bearing capacity, therefore soil improvement was needed to increase the strength of the soil. One of the damaged roads that occur due to the lack of soil bearing capacity is at Priyayi Mosque Village Road, Kasemen District, Serang City which has a low carrying capacity with a CBR value of 1.99%. In this study, several tests were carried out, soil physical and California Bearing Ratio test. Soil physical tests carried out were water content, soil density, grain size analysis, Atterberg limits, compaction test and, CBR with the addition of slag cement with variations of 0%, 5%, 10%, 15% based on Variation of optimum wet side moisture content. The result of soil physical properties testing obtained the type of soil is an organic clay with high plasticity. The results of the California Bearing Ratio test on the original soil had a CBR value of 2.4% and there was an increase to the optimum at the addition of 15% Slag Cement in 0 and 3 days of curing with a CBR value of 11.2% and 15.25%. Based on these results, it can be concluded that the cement slag content of 15% with 3 days of curing time can increase the bearing capacity of the soil and fulfill the requirements as a good road subgrade

In this paper, numerical DEM simulations are presented that were used to study the response of agricultural granular materials, such as dry soybeans, in a uniaxial compaction test. To this aim, the...

In this research, the potential improvement of some geotechnical characteristics of soft clay soil using the low Calcium fly ash was evaluated. (These characteristics include unit weight, shear strength, compaction characteristics and soil plasticity characteristics). In addition, the X-ray diffraction test was performed to measure the mineralogical changes in the soft clay soil when the low Calcium fly ash is added. The ordinary Portland cement was used to activate the fly ash. The total percent of flash and cement was10% to investigate the variation in the effectiveness of activation. The optimum moisture content that which computed by the compaction test was adopted in the rest of the experimental program. The test results revealed that the cement could be used to improve the activating of the fly ash efficiently. The maximum value of dry density was marginally affected due to activation from 1.747 to 1.738 g/cm3 along with a corresponding change in optimum water content from 17.45 to 15.5 %. The soil cohesion parameter increased from 188 to 206 kN/m2 whereas the angle of internal friction rose from about 56.7o to 59.1o. Finally, the results of the unconfined compression test reveal that the cement-activated fly ash could present better results than those obtained from a 28-days curing cement.

The investigation aims to check the effect of variation of gypsum and water content on the engineering properties of expansive soil by different experiments, namely, mini compaction test, Atterberg limit’s test, and unconfined compressive strength test along with microstructural analysis. The effect of gypsum (0%, 2%, 4%, 6%, 8%, and 10%), water content (ωopt − 3%, ωopt, and ωopt + 3%), and curing period up to 28 days on the strength of bentonite-gypsum mixtures was highlighted. The results of bentonite-gypsum mixtures showed an increment in maximum dry unit weight and decrement in the optimum water content up to 4% inclusion of gypsum. A gradual reduction in the liquid limit and plastic limit of bentonite-gypsum mixtures was observed with the increase in gypsum content and curing period. The unconfined compressive strength of the bentonite-gypsum mixtures increased continuously with the increase in gypsum content, water content, and curing period. The microstructural behavior of bentonite-gypsum mixtures showed evidence of pozzolanic product formation along with densification of the composite. The multiple regression analysis was also carried out to establish the relationship between the strength and maximum dry unit weight, liquidity index, and the additive content as well as curing period.

Metakaolin has been widely used as pozzolanic additive to improve the pozzolanic activity of lime-based products. In this study, the normal standard Proctor compaction test was performed on metakaolin with (5% lime) and without (0% lime) lime addition. The changes in stiffness, suction, and microstructure with remoulding water content were investigated on statically compacted samples. Results show that lime-treated metakaolin exhibits a 1.5-peak compaction curve, while untreated metakaolin exhibits common one-peak compaction curve. The uncommon shape of the compaction curve of the treated metakaolin can be explained by the non-fully developed soil suction when water is not continuous. Treated and untreated samples compacted at both dry and wet of optimum show uni-modal pore-size distribution characteristics, indicating the absence of aggregates. This is related to the specific thermal treatment, forming separate metakaolin platelets and leading to a modified uniform structure with diffuse platelets. The soil stiffness is rather dominated by the number of particle contacts or soil dry density, the effect of suction being insignificant. For the suction changes, on the dry side, the effect of pore-size distribution prevails facing the effect of water content, while on the wet side it is the effect of water content that becomes dominating.

A data set of the coefficient of vertical subgrade reaction for a plate diameter of 30 cm, KP.FWD, measured by Portable Falling Weight Deflectometer tests in full-scale compaction tests on sandy soil using various types of compaction machines was analysed. Based on this analysis and the previous analysis of a CBR data set from another full-scale compaction test series, a set of conclusions could be drawn. The soil stiffness indexes (SSIs), CBR and KP.FWD, can be expressed by, respectively, an empirical equation multiplying a function of ρd and another of Sr, where CBR and KP.FWD decrease significantly as Sr increases. As such, ρd values cannot be estimated from SSI alone. By fixing the field ρd – w compaction curve by keeping the soil type and the field compaction energy level, CELf, to those in the field compaction tests in which the SSI – ρd – Sr correlation has been calibrated, field compacted ρd & w states can be estimated by measuring the SSI values. Then, by the upper-bound and lower-bound control of SSI, the field compacted states approach the specified target, where, typically, ρd = the maximum dry density for CELf and Sr = the optimum degree of saturation, (Sr)opt. A method to incorporate this indirect but fast SSI-based compaction control into the conventional ρd & w-based compaction control is proposed.

The aim of the study is to evaluate the effects of adding the waste marble dust to soil on the compaction characteristics of the soil. Standard Proctor test is conducted for two groups of samples (Group 1 without marble dust group N = 17; group 2: Soil with marble dust N = 17). The test results show that the optimum moisture content (OMC) of soil decreases and the maximum dry density (MDD) increases due to the addition of marble dust with the soil. There is a significance difference between the two groups of soil as the value of p

The paper discusses the comparison of fly ash with Lapindo mud as a land stabilizer for a landfill in Pasuruan, Indonesia. Land for landfills has a low level of stability due to the condition of garbage that has accumulated and undergoes a process of decay. This land condition is less favorable to support the construction of the building above it if one day the location is used for construction. Therefore, it is necessary to stabilize the soil first. The purpose of this study was to determine the effect of adding a mixture of TPA soil with fly ash and Lapindo mud. The method used by sieve testing and compaction of the specimens for each treatment consisted of a mixture of TPA soil with fly ash and TPA soil with Lapindo mud, while the percentages of fly ash and Lapindo mud to the dry weight of the original soil were respectively 0 %, 10 %, 15 %, and 20 %. The results showed that stabilization of the landfill with fly ash reduced the silt content while stabilization with Lapindo mud increased the levels of silt in the landfill so that fly ash was better than Lapindo mud for stabilization of the landfill. The specific gravity values for both stabilization mixtures increased equally. Based on the results of the standard compaction test for the addition of a mixture of fly ash, the OMC value decreases and the greater the value of dmaxs indicates that fly ash is good for landfill stabilization, while the addition of a mixture of Lapindo mud increases the OMC the smaller the value of dmaxs. For the direct shear test of the two mixed soils, the value of the internal friction angle (Æ) increased. The percentage value of the optimum mixture of mixed soil+fly ash is 14 % with an internal shear angle (Æ) of 38°, while the stabilization of landfill with Lapindo mud obtained the optimum mixture percentage value of 11 % with an internal shear angle (Æ) of 31°, В статье обсуждается сравнение летучей золы с грязью Лапиндо для стабилизации грунта на свалке в городе Пасуруан, Индонезия. Земля на свалках имеет низкий уровень устойчивости из-за накопившегося и разлагающегося мусора. Такое состояние земли неблагоприятно для строительства. Поэтому в первую очередь необходимо стабилизировать почву. Целью данного исследования было определить влияние добавления смеси почвы места окончательного хранения отходов (МОХО) с летучей золой и грязью Лапиндо. Метод предполагал ситовый анализ и уплотнение образцов для каждой обработки, состоящие из смеси почвы МОХО с летучей золой и почвы МОХО с грязью Лапиндо, при этом процентное соотношение летучей золы и грязи Лапиндо к сухому весу исходной почвы составляло соответственно 0 %, 10 %, 15 % и 20 %. Результаты показали, что стабилизация почвы свалки с помощью летучей золы снизила содержание ила, в то время как стабилизация грязью Лапиндо повысила уровень ила на свалке, соответственно летучая зола является более подходящей для стабилизации почвы свалки, чем грязь Лапиндо. Значения удельного веса для обеих стабилизирующих смесей увеличились одинаково. На основании результатов стандартного испытания на уплотнение при добавлении смеси летучей золы, значение оптимальной влажности грунта уменьшается, более высокое значение dmaxs указывает на то, что летучая зола пригодна для стабилизации свалки, в то время как добавление смеси грязи Лапиндо увеличивает значение оптимальной влажности грунта, тем меньше значение dmaxs. При испытаниях на прямой сдвиг двух смешанных грунтов значение угла внутреннего трения (Æ) увеличилось. Процентное значение оптимальной смеси грунт+летучая зола составляет 14 % при угле внутреннего сдвига (Æ) 38°, в то время как при стабилизации свалки грязью Лапиндо оптимальное процентное значение смеси составило 11 % при угле внутреннего сдвига (Æ) 31°., У статті обговорюється порівняння летючої золи з гряззю Лапіндо для стабілізації грунту на звалищі в місті Пасуруан, Індонезія. Земля на звалищах має низький рівень стійкості через сміття, яке накопичилося і розкладається. Такий стан землі несприятливий для будівництва. Тому в першу чергу необхідно стабілізувати грунт. Метою даного дослідження було визначити вплив додавання суміші грунту місця остаточного зберігання відходів (МОЗВ) з летючою золою і гряззю Лапіндо. Метод передбачав ситовий аналіз і ущільнення зразків для кожної обробки, що складаються з суміші грунту МОЗВ з летючої золою і грунту МОЗВ з гряззю Лапіндо, при цьому процентне співвідношення летючої золи і грязі Лапіндо до сухої ваги вихідної грунту становило відповідно 0 %, 10 %, 15 % і 20 %. Результати показали, що стабілізація грунту звалища за допомогою летючої золи знизила вміст мулу, в той час як стабілізація гряззю Лапіндо підвищила рівень мулу на звалищі, відповідно летюча зола є більш придатною для стабілізації грунту звалища, ніж грязь Лапіндо. Значення питомої ваги для обох стабілізуючих сумішей збільшилися однаково. На підставі результатів стандартного випробування на ущільнення при додаванні суміші летючої золи, значення оптимальної вологості грунту зменшується, більш високе значення dmaxs вказує на те, що летюча зола придатна для стабілізації звалища, в той час як додавання суміші грязі Лапіндо збільшує значення оптимальної вологості грунту, тим менше значення dmaxs. При випробуваннях на прямий зсув двох змішаних грунтів значення кута внутрішнього тертя (Æ) збільшилося. Процентне значення оптимальної суміші грунт+летюча зола становить 14 % при куті внутрішнього зсуву (Æ) 38°, в той час як при стабілізації звалища гряззю Лапіндо оптимальне процентне значення суміші склало 11 % при куті внутрішнього зсуву (Æ) 31°.

Wood fly ash stabilised road base layers with high recycled asphalt pavements content was studied both at the laboratory and in-situ. The original recipe was chosen based on an actual stabilised pavement base layer design with cement CEM II/B-T 42.5R but optimised using wood fly ash. The existing road base layer from gravel was mixed with dolomite aggregate and recycled asphalt pavement, adding cement and wood fly ash at different proportions. The mixture was compacted at optimal water content according to the Standard Proctor test and further conditioned. Resistance to freezing and thawing of hydraulically bound mixtures was checked after 28 days of conditioning. Even 50 cycles of freezing and thawing were used. Test results indicated wood fly ash as an effective alternative to the typically used cement for road base stabilisation, including recycled asphalt pavement material. Three hydraulically bound mixtures were chosen for test sections in the pilot project. The project includes five different sections with three different hydraulic binder recipes. The performance of each section was evaluated.

Quarry dust is a waste material which could pose as a serious environmental risk factor, which requires proper handling for safety. Also to harness locally available materials, lateritic soil and quarry dust have been an attractive proposition. This work studied 0–180 min at 30 min intervals of elapsed time between mixing operation and compaction for lateritic soil treated with lime and quarry dust. Constant dosages of lime 2, 4, 6 and 8% were mixed with variations of quarry dust of 3, 6, 9, 12, 15 and 18%; all percentages were measured by weight of the dry lateritic soil. Preliminary tests were conducted on the natural lateritic soil for characterization. The clay minerals present in the lateritic soil were identified using X-ray diffraction technique while the mineral oxide composition of quarry dust was done using X-ray fluorescent technique. The tests carried out on the treated lateritic soil were compaction test (British Standard Light), California Bearing Ratio (CBR) and unconfined compressive strength (UCS). The lateritic soil was classified to be A-6 (3) in the AASHTO rating system and Clayey Sand (SC) in the Unified Soil Classification System. The predominant non-clay mineral and clay mineral present in the soil were quartz and kaolinite, respectively, with traces of Moganite, Gismondine, Sanidine, Muscovite and Dickite. The quarry dust was found to satisfy the requirements for good pozzolanic materials. The Atterberg limits for the treated lateritic soil all reduced with increase in lime and quarry dust contents. The compaction and strength characteristics of the treated lateritic soil all reduced with increase in elapsed time between mixing and compaction. The California bearing ratio and the unconfined compressive strength at 7 days of curing period increased by 230.77% and 126.61%, respectively, at the addition of up to 8% of lime and 18% of quarry dust contents. A predictive model of good fit was developed for maximum allowable time elapsed between mixing operation and compaction for any given mix and strength characteristics. The correlation coefficient “R” and coefficient of determination “R2” are 0.902 and 0.814, respectively. Also at 95% confidence level, lime content, quarry dust content, optimum moisture content (OMC), California bearing ratio (CBR) and unconfined compressive strength (UCS) all affected the elapsed time between mixing and compaction significantly.

This research presents experimental results of dredged lakebed sediment-stabilised with ordinary Portland cement (OPC) and fly ash (FA) for use as pavement materials in road infrastructure. The work also proposed empirical correlations for the strength and stiffness parameters of chemically stabilised dredged sediments intended for pavement engineering. The dredged sediment was collected from the drop-off area around Phayao Lake in Thailand. The sediment’s optimal moisture content was determined by a Proctor compaction test. The OPC and FA content ranged from 3 to 10% and 5 to 20% per dry weight of sediment. The shear strength of treated sediments at different curing time was measured using the unconfined compression (UC) test. The optimum FA content proved to be most effective in generating the highest material strengths and stiffnesses from the stabilised sediments, regardless of OPC contents and curing duration. A suitable replacement ratio of cement with fly ash was 15%. The results were compared with data on other types of chemically stabilised sediments available in literature. Correlations between engineering properties and design parameters such as UCS, E50, $${\upvarepsilon }_{f}$$ , and eot can be suggested based on the comprehensive experimental results. Using OPC and FA as admixes together provided the greatest improvement in the strength characteristic of dredged sediment. In addition, the study presented an empirical correlation between the strength and stiffness of adding fly ash on cement-stabilised lakebed sediment for using in geotechnical and pavement works.

The purpose of this research is to determine the physical properties of clay soil and to analyze the effect of adding coconut shell charcoal ash to the clay soil. The soil samples used in this study came from Tanralili District, Maros Regency, two sample points were taken and the variations in the levels of addition of coconut shell charcoal ash is 0%, 4%, 6%, 8%, 10%. The test method used refers to ASTM (American Society for Testing Materials). The tests carried out were testing the physical properties of the soil in the form of moisture content, specific gravity, Atterberg boundaries, filter analysis, and hydrometer analysis, then a compaction test was carried out to determine the maximum soil density. The results of the test obtained a moisture content value of 28.811%, a specific gravity of 2.58 g / cm3 so that it is classified as organic clay. As well as the plasticity index value of 9.926% with moderate plasticity from the 7% -17% interval. Then from the test results of soil compaction testing with the addition of coconut shell ash, the dry density (gdry) equal to 0.862, 0.886, 0.914, 0.943, 0.962, this means that the soil sample experienced an increase in dry density (gdry) of 11.60%. From the research results it can be concluded that the addition of coconut shell charcoal ash can increase the value of soil dry density so that it can be used to increase the value of the carrying capacity of clay soil.

Leaking tanks may lead to severe contamination of their surrounding soil. The geotechnical behavior of the soil varies with the physicochemical processes that occur between the contaminant and the soil. In this respect, studying the geochemical properties of gasoline-contaminated soils and sediments seems to be important for engineering and especially environmental purposes. In this paper, laboratory tests were carried out to examine the effects of crude gasoline contamination on some of the geotechnical properties of a silty soil sampled from the Mashhad plain, located in the northeast of Iran. Tests consisted of basic properties, Atterberg limits, compaction, direct shear, and uniaxial compression tests, which were carried out on clean and contaminated soil samples at the same densities. The contaminated samples were prepared by mixing the soils with crude gasoline in the amounts of 3%, 6%, 9%, and 12% of dry weight and curing periods of 0, 7, 15, and 30 days. Results indicated a decrease in the friction angle and an increase in the cohesion of the soil by increasing gasoline content. Besides, a reduction in the maximum dry density and optimum moisture content was observed in the compaction test. The increase in gasoline percentage up to 6% also showed a direct effect on increasing the liquid limit and plastic limit of silty soil, which decreased thereafter. Moreover, any increase in gasoline percentage had a reverse effect on the modulus of elasticity of the soil. The increase in gasoline percentage up to 3% also had a direct impact on the uniaxial compressive strength of the soil, exceeding which it started to decline. Finally, the effects of contamination duration were examined by testing contaminated samples in periods of 7, 15, and 30 days under natural conditions. The results showed a reverse relationship with all geotechnical properties due to aging and a reduction in the gasoline content due to the evaporation of volatile compounds. Also, the numerical analysis of the laboratory results indicated an increase in settling and the percentage of shear strain beneath the foundation with increasing the contamination level, confirming the laboratory results.

Expansive soil is one of the problematic soils for civil engineering construction. The high swelling-shrinkage nature results in deformations that can damage the construction on it, therefore it is necessary to make improvements in expansive soil. One of the most widely used methods of improving expansive soil is stabilization using chemical additives. In this research using coal waste material (fly ash) as stabilizer from PLTU Sekayan in Kaltara Province, so it can be said as environmentally friendly stabilization. The research objective was to determine changes in engineering behavior of expansive soil through compaction tests and CBR. The test results will be displayed in graphical form, namely by comparing the expansive soil that has not been stabilized (initial conditions) and the expansive soil that has been stabilized with fly ash at mixed variations of 20%, 30% and 40%, and has passed the curing period for 5, 15, and 30 days. From this research, it was found that the addition of a stabilizer (fly ash) could improve its engineering properties, and the optimum results were obtained at the addition of 40% fly ash and after 30 days of curing time. From the compaction test, it was found that the volume weight of dry soil (γdry) increased by 14.05% from 1.21 gr/cm3 to 1.38 gr/cm3 and the optimum water content (wopt) decreased by 38.12% from 31.19% to 19,3%. From CBR testing in the laboratory, there was a very large increase in the value of CBRDesign, namely 2192% from 0.72% to 16.5%

This study was conducted on durability of the clayey-sand stabilized using the copper slag (CS)-based geopolymer against wetting-drying (W-D) cycles. In this investigation, the mix of 0, 10, and 15% CS and alkaline activator liquid was used. In this solution, the ratio of NaOH to Na2SiO3 is 70:30 and the weight ratio of CS to solution is 1:1. To evaluate the effects of CS content and NaOH concentration (8 M and 11 M) on the strength, durability, and microstructural variation, a series of experiments were conducted after different cycles. The tests carried out for this purpose include standard proctor compaction test, unconfined compressive strength (UCS), Atterberg limits, accumulative loss of mass, swell and shrinkage, ultrasonic P-wave velocity, pH, toxicity characteristic leaching procedure (TCLP), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) tests. The UCS results demonstrated a remarkable reduction in cycle 2 due to W-D cycles, followed by a decrease in further cycles. As a result of Atterberg limits, lower PI leads to the lower potential to swell or shrinkage; thus, the lower loss of soil mass with a higher amount of CS content is obtained. The microstructure analysis showed that with the increase in cycle number, the abundance of microcracks and voids were increased. Moreover, dissolved geopolymerization products leached due to wet cycles and formed gel becomes weaker. The results showed that all the chosen mixtures were durable and endured all 12 W-D cycles. Furthermore, their mass loss was lower than allowable mass loss content of ASTM D559, suggesting that this stabilization method was appropriate for this soil.

Natural polymer (biopolymer) treatment of engineered soil/waste is recognized as an environmentally-friendly sustainable method. This paper presents the findings in the improvement of strength characteristics of bauxite residue (red mud tailing) using two microbial biopolymers, xanthan (XG) and guar gum (GG), used individually and also together as a composite. A set of laboratory tests namely compaction test, sieve and hydrometer analysis, Atterberg limits, unconsolidated undrained triaxial (UU) test, unconfined compression (qu) test, chemical analysis, X-ray diffraction (XRD) and scanning electron microscopy (SEM) have been performed on biopolymer stabilized specimens at varying biopolymer concentration and curing period. The results showed that qu increases polynomially with the increase in biopolymer content (P) and curing period (t). Also, when compared with the conventional method, qu at 0.5% XG was similar to 10% cement stabilized bauxite residue at 28 days curing period. The influence of a composite biopolymer on the strengthening behaviour of bauxite residue is also observed due to the additional ability to create a cross-linking network. XRD and SEM micrographs have also confirmed that bauxite residue particles are linked through the biopolymer, resulting in improved shear resistance. Finally, considering environmental perspectives, the economic feasibility of biopolymer treatment is also examined in comparison to cement and found that the biopolymer usage is an excellent substitute to the conventional engineered materials (cement) for soil/waste treatment.

Analysis of reduced Proctor test and standard Proctor test results collected from literature indicates that it is possible to replace standard Proctor with reduced Proctor due to the advantages that the reduced Proctor test requires 40% less compaction energy, requires no modifications to the standard Proctor compaction apparatus unlike other small compaction tests, and the soil particle size requirements remain the same as those for the standard Proctor test. Correlations were also developed for compaction characteristics obtained by the modified Proctor test and the reduced Proctor test in order to estimate compaction characteristics at the modified Proctor energy level by just performing the reduced Proctor test. The optimum moisture content was found to correlate well with liquid limit. In addition, for the reduced Proctor test, maximum dry density was found to have a very good correlation with optimum moisture content.

Ensuring the sustainability of critical and limited natural soil resources is a major challenge in arid regions such as Kuwait. Investigations should be performed to identify and characterise collapsible surface soil deposits, and collapse potential should be assessed if possible in order to evaluate suitable stabilizing techniques. The cementation effect of different types of salts gives arid soils their considerable strength and stiffness in dry conditions. The collapse in these soils may occur due to the reduction of the chemical or physical bonds between the soil particles under wet conditions. Collapse Potential (CP) is an indication of the collapsibility of these soils. This paper presents the results of experimental work that was carried out to evaluate the collapse potential of two types of surface soil: sabkha soil and dune sand. The experimental program included physical and chemical soil characterization alongside a modified compaction test. The collapsibility of the soil at a stress of 200 kPa was obtained by performing a Single Collapse Test (SCT) via a conventional odometer device in a temperature- and humidity-controlled environment. Collapse potential index tests were performed on the tested soil samples collected from eight locations in two study areas. The results suggest the problem severity is slight to none. However, the CP was higher for the sabkha soil samples than for the dune sand samples. The increase in collapsibility of the sabkha soil samples may be attributed to the removal of bonding between cementing particles upon wetting.

Attempts have been made to address the strict regulations on eco-friendly construction and recycle aggregate resources, encouraging researchers to consider the utilization of recycled aggregates for the backfilling of underground power systems. It is essential to recognize the physical and thermal characteristics of domestic recycled aggregates for use as backfill materials for underground power conduits in Korea. Herein, the thermal properties of concrete-based recycled aggregates with different grain-size distributions are evaluated, and the particle breakage effect of recycled aggregates is identified through the compaction tests. The thermal properties of the recycled aggregates and the river sand were measured using a transient hot wire method after a standard compaction test. The particle breakage effect was also investigated during the standard compaction test. The thermal resistivities of the recycled aggregates and the river sand showed a similar trend, which were decreased with an increase in the water content at the same dry unit weight. In addition, particle breakage during compaction led to an enhanced compaction effect, reducing the thermal resistivity and increasing the fine particle content. This study shows that the recycled aggregates can be promising backfill materials that substitute natural aggregates when backfilling underground power conduits.

The Proctor test method, as specified in AASHTO T134 and ASTM D558, continues to play a vital role in design and construction quality control for soil-cement materials. However, neither test method establishes a methodology or standardized protocols to characterize the effects of time delay between cement addition and compaction, also known as compaction delay. Compaction delay has been well documented to have a notably negative effect on compactability, compressive strength, and overall performance of soil-cement materials, but specification tools to address this behavior are not prevalent. This paper aims to demonstrate the extent of compaction delay effects on several soil-cement mixtures used in Mississippi and to present recommended new test method protocols for AASHTO T134 to characterize compaction delay effects. Data presented showed that not all soil-cement mixtures are sensitive to compaction delay, but some mixtures can be very sensitive and lead to a meaningful decrease in specimen dry density. Recommended test method protocols were presented for AASHTO T134 and commentary was presented to provide state Departments of Transportation and other specifying agencies a few examples of how the new compaction delay protocols could be implemented.

Copper has been widely in many applications such as heat exchangers due to mechanical and physical properties. In this work, the composite foam was fabricated by powder metallurgy method with fly ash powder and egg yolk as a foaming agent and reinforcement, respectively. Mechanical properties of the specimen were characterize using a compaction test. Moreover, observation of the specimen was conducted using the measurement of shrinkage and porosity. The strength of the specimen was obtained in the range 1:1,25 is 0,26 MPa through compaction test. Porosity measurement revealed that maximum and minimum porosities are 88.79 % and 71.53%, respectively. Optical Microscope and Scanning Electron Microscopy observation size of the pores ranging from 21,63μm to 169,7μm. Moreover, some crystalline phase was observed using X-Ray Diffraction Test.

Recently, the use of plastic products, such as polyethylene (PE) bottles and polypropylene (PP), has been significantly increased, which may lead to many environmental issues. Therefore, it is important to find methods to manage these waste materials without causing any ecological hazards. One of these methods is to use plastic wastes as soil stabiliser materials. In this study, PE and PP have been used in the form of fibres. The effect of the stabilisation was evaluated through carrying out standard laboratory tests. These tests have been conducted on natural and stabilised soils with four fibre contents (1%, 2%, 3%, and 4%) of the soil weight. The tests included the standard compaction test, unconfined compressive strength (UCS) test, California Bearing Ratio (CBR) test, and resilient modulus (Mr) tests. In all these tests, the fibre content was added in two lengths, which were 1.0 cm and 2.0 cm. Laboratory test results revealed that the plastic pieces decrease maximum dry density (MDD) and optimum moisture content (OMC) of the stabilised soils, which are required for the construction of embankments of lightweight materials. In addition, there was a significant improvement in the UCS of soils by 76.4 and 96.6% for both lengths of PE fibres and 57.4% and 73.0% for both lengths of PP fibres, respectively. Results of the CBR tests demonstrated that the inclusion of plastic fibres in clayey soils improves the strength and deformation behaviour of the soil especially with 4% fibre content for both lengths 1.0 cm and 2.0 cm, respectively, to a figure of 185 to 150% for PE and PP, respectively. Furthermore, the results of the Mr tests demonstrated that the mechanical properties improved to an extent. For an increase in fibre content, the resilient modulus increased by about 120% at 4% fibre content for PE. However, for PP, improvement in resilient modulus declined at 3% fibre content. Therefore, for soil stabilisation with fibre material, optimum fibre content shall be sought.

Heaving soils are the most problematic worldwide. These soils develop swelling stress that produces uplift forces detrimental to the foundations. In engineering practice, swelling stress is not considered in general. Considering the swelling stress in foundation design enhances the service life of construction. The oedometer swelling test is the technique ordinarily used to assess the swelling stress. Nonetheless, the oedometer swelling test is cumbersome, time-consuming, making the test unattractive, and not cost-effective for the low-cost housing project. The objective of this research work is to propose a model to predict swelling stress as an alternative to oedometer testing. Geotechnical studies such as Atterberg limits, particle size distribution, free swell ratio, specific gravity, linear shrinkage, suction measurement, Proctor compaction test, and zero-swell test are performed to estimate the soil properties. Multivariate regression analysis is performed using NCSS.11 Program to develop the predictive model. The model is assessed base on the following: determining coefficient value, comparing predicted values with experimental values, comparing the proposed model with other existing models found in the literature. Besides, the Box-cox transformation function is used to improve the accuracy of the model. The developed model can be utilized to assess the swelling stress of compacted heaving soils, and it is much more accurate than other existing models.

The management and disposal of municipal solid waste (MSW) in many countries has changed significantly. To overcome the risk to environment and humans, landfills are designed and constructed to dump the waste in the ground and covered with soil, vegetation to protect the environment. Engineered landfills are provided with various liner systems. Liners used in the landfill acts as a barrier to water, leachate and other liquid materials. Liners also protect the ground from solute concentration. In the present study, compacted clay liners of various thicknesses are used. A numerical model of a landfill with the clay liner is designed and analysis is performed using GeoStudio software. In this software CTRAN/W module is used for contaminant transport analysis. From the landfill at different radial distances three bore holes are provided with varying depths respectively, also clay liner thicknesses of 0.5 m, 1.0 m, 1.5 m. Tests on the soil like standard proctor test and hydraulic conductivity tests are conducted. Results shows, with the increase in liner thickness, time taken by the contaminant transport to reach bore wells increases. Results also show the rate of variation in concentration of the leachate at each bore well in certain time period.

The study aims to propose a mathematical approach to determine the optimum moisture content ( ) and the corresponding maximum dry unit weight ( ) of unsaturated fine-grained clay soils with accuracy. Laboratory tests such as grain size distribution, Atterberg limits, specific gravity, Proctor compaction test, and soil suction measurement are conducted to assess soil properties. The WOP and are determined using the mathematical approach based on differential function (∂) and the graphical method. The differences in optimum moisture content values between the mathematical approach and the graphical method ( ) values are 0.43 %, 0.36 %, 0.42 %, 0.24 %, respectively for soils PES, BFS, WIS, BES, and induced differences in total suction of 179.17 kPa, 144.00 kPa, 175.00 kPa, 96.00 kPa, respectively for soils PES, BFS, WIS, BES. Moreover, the differences in matric suction are 148.27 kPa, 116.13 kPa, 144.83 kPa, 80.00 kPa, respectively for soils PES, BFS, WIS, BES. and values are smaller than 0.5 % and marginal in the context of saturated soil mechanics. However, the total suction and matric suction values induced by values are significant for unsaturated soils. An accurate estimation of and can be performed on unsaturated compacted soils using the mathematical approach.

Soft soil was one of the most widely encountered problems in construction, especially for archipelago countries which most of its area was lowland with a high deposit of soft soil. To overcome this problem, soil stabilization was one of the most widely used as a solution. Soil stabilization in general uses chemical substances that are classified as pozzolan material. Pozzolan material uses its capability to strengthen the cohesion of soil grains. Mostly, pozzolan material consists of silica. Overboulder asbuton and zeolite were examples of natural pozzolan material in Indonesia. Both materials have a high silica content. Thus, the author interested to figure out the mechanical behavior of these two substances as a soil stabilizer. This research was a correlating study to the previous paper with the same author which discusses the overboulder asbuton as a soil stabilizer. Overboulder added to the mix is determined as 15%, with varied zeolite percentages applied to examine the differences. The UCT was conducted according to ASTM D-2166 as a parameter. As the standard remolding method, a standard proctor test was conducted to determine the optimum moisture content and the maximum density of each mix. While the UCT specimens were tested at the certain curing time for each composition. The curing time applied was 0, 7, 14, and 28 days. By this curing period, the effective pozzolanic reaction that occurs for each composition could be determined. The result shows that zeolite addition to overboulder asbuton could increase the soil density and increase its compressive strength. It is indicated that overboulder asbuton and zeolite mix could be a proper alternative as a soil stabilizer. Doi: 10.28991/cej-2021-03091635 Full Text: PDF

Soil stabilization is a process of altering the properties of soil by physical or chemical means. It leads to improvement of engineering quality of soil such as density, permeability, bearing capacity, shear strength etc. Soil stabilization can be easily achieved by means of certain chemicals or physical processes such as by using cement, lime, fly ash etc but here we will try to use plastic wastes for this purpose. By using this product, we can make use of plastics which always lies around our environment to pollute it. Use of plastics is increasing in day to day life and our society is strongly attracted towards it but the disposal of such a huge mass is impossible and if possible creates land pollution like problems. We can also save a lot of Cement, Lime, Fly ash which was supposed to be used in soil stabilization and can now be used in some other construction purposes. A series of tests were carried out on soil to check the improvement in engineering properties like standard proctor test, unconfined compression test and California bearing ratio test. We can have three benefits from this project like utilization of natural resources, Economy and waste management. Thus a waste thought to be harmful and dangerous to our society can now be converted to a boon to our society.

Researchers globally due to little cost and effective results in engineering applications frequently use the waste material. Every year millions of ton of waste like Fly ash, lime, gypsum had generated from the kilns. In addition, mainly in this research focused on application of Silty Sand, Which have been produced on very large scale along the dam site, A huge amount of the this sand went for dumping to the nearby site. The dumping of Fly ash from industries near habitable areas poses environmental threats like air pollution, water contamination and affects biodiversity. This empirical investigation mainly focused on utilization of waste material like Silty sand, Lime and Gypsum to replace Fly ash in different mixes. In this research different mix have prepared by addition of Silty sand, Lime and gypsum to the voluminous weight of Fly ash, and silty sand have added in four different percentage of mixes to replace Fly ash by 10, 20, 30 and 40% by weight. Following tests have conducted standard proctor test and unconfined compressive strength test and final the result of test reveals that by addition of 10% of silty sand and the samples and cured by burlap method Unconfined compressive strength have highest i.e. 64.58 KPa with 56 days curing period.

Some soils cannot withstand heavy loads due to significantly low California Bearing Ratio and shear strength. So, to reduce this problem treatment of soil is needed to be done using different stabilizers like furnace slag, fly ash, limestone fines, bitumen, plastic waste etc. It is defined as the process for improving the properties of the soil either providing physical or chemical treatments and by blending and mixing of some other materials with the soil. It helps in controlling the shrink-swell properties of soil and also improves the shear strength properties and the capacity of soil to support the loads. This paper is aimed at providing soil stabilization using the waste plastic. The main motive of this research is to evaluate the result of incorporating waste plastic bottles on the geotechnical properties of soil. Various percentages of waste plastic bottles (0%, 0.5%, 1.0%, 1.5% and 2.0%) added in the soil sample and sequel the engineering properties of soil. For this, various laboratory tests were conducted on soil samples like Unconfined Compressive Strength, California Bearing Ratio, and Proctor Test etc. and compared with the soil samples without any plastic waste. The outcome of the study showed that addition of the waste plastic bottles have positive effect on the soil properties which promotes the re-use of waste plastic from industry in an economical and environmentally friendly way and it will also help with the disposal problem of these plastic wastes on some extend.

The air-entry value (AEV) is a fundamental parameter of the soil-water characteristic curve (SWCC). AEV is the minimum matric suction value required for entry of air into soil voids. The primary objective of this research work is to assess the impact of geotechnical index properties, swelling properties, mineral composition on AEV of compacted heaving soils, and discuss how they affect AEV. Soil properties were investigated through lab tests such as grain size distribution (GSD), specific gravity, Atterberg limits, linear shrinkage, free swell index, free swell ratio, X-ray diffraction, compaction test, and soil suction measurement. SWRC Fit program was used to perform non-linear fitting of the SWCC based on models VG, DB, FX, LN, and BL. Surface plot of data was used to characterize the impact of soil properties on AEV. It was observed that AEV is ranging from 10 kPa to 20.20 kPa, models DB and BL gives the best fitting SWCC. The percent of smectite mineral exhibits a significant impact on AEV. Swelling properties such as free swell index and free swell ratio influence the AEV with a respective determination coefficient of 85.72%, 88.68%. The plasticity index, linear shrinkage, specific gravity, and dry unit weight impact the AEV with a respective determination coefficient of 95%, 95.45%, 90.43%, 94.29%. The fine-grained content, clay fraction, void ratio, and water content influence the AEV with a respective determination coefficient of 97.95%, 84.89%, 80%, 94.31%. The finer the soil, the higher the AEV. The activity of clay and percent of illite mineral exhibit a marginal effect on the AEV.