Civil engineering structures made upon expansive soils known in India as Black Cotton (BC) soils are susceptible to structural damages due to their seasonal swell-and-shrink behaviour. This study focuses on assessing the mechanical performance of BC soil stabilised using unconventional binders, specifically Sugarcane Bagasse Ash (SCBA) and Ground Granulated Blast Furnace Slag (GGBS) with different proportions. The experimental evaluation included Compaction tests, Unconfined Compressive Strength (UCS) tests, Triaxial tests, and Atterberg's limits tests. Additionally, mineralogical and morphological studies were carried out using x-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDS), and chemical analysis using x-ray fluorescence spectroscopy analysis (XRF). The results showed that the mixture containing 21% SCBA and 9% GGBS produced cementitious-siliceous-hydrate (C-S-H) molecule, which improved the strength. Based on the soil-binder percentage ratio obtained from UCS tests, a regression equation was developed to estimate consolidated soil strength. The regression model, exhibiting an impressive R2 value of 93.69%, was analysed within the framework of existing empirical correlations by other researchers. This statistical model, with its good fit, is a useful tool for evaluating the compressive strength of stabilised expansive soil. The findings provide insights into successful stabilisation solutions for expansive soils found locally and globally.

Expansive soils swell when wet and shrink when dry, causing differential settlements that can lead to structural failures in roads and buildings. In cases where these soils cannot be avoided, improving their stability is essential. This study investigates the use of two binders, ground granulated blast-furnace slag (GGBS) and bagasse ash (BA), byproducts of steel and sugarcane processing, respectively, to reduce soil swelling and enhance stability by assessing the mechanical behavior of reinforced expansive soil. To evaluate the behavior of reinforced expansive soils, tests such as Atterberg limits, compaction, swelling potential, and direct shear were conducted. Results indicated that as reinforcement levels increased to an optimal threshold (3 % GGBS and 12 % BA), the optimum moisture content rose, while maximum dry unit weight generally decreased. A 15 % increase in moisture content and a 3.16 % decrease in maximum dry unit weight were observed with reinforcement. Cohesion decreased by 27 % in soaked conditions and 31 % in unsoaked, while the angle of internal friction rose by 106 % and 111 %, respectively, at the maximum reinforcement threshold. These additives also improved shear strength, reduced swelling potential, and lowered plasticity index, shifting the soil behavior from clay-like to silty. The results show that bagasse ash and GGBS effectively enhance soil properties and provide a sustainable solution for soil stabilization in construction.

Black cotton (BC) soil poses threats to build structures owing seasonal volumetric changes. The production of fly ash (FA) and bagasse ash (BA) increasing abundantly, and their improper disposal poses detrimental effects on the environment and human health. This research aims to develop sustainable, novel, optimum binary blend by using FA and BA to improve the strength characteristics of the BC soil after curing periods of 7, 14, and 28 days. BA was mixed in different ratios by dry weight of FA to obtain the optimum binder based on maximum UCS. The optimum binder comprising of 80:20, mix by dry weight of BC soil in varying proportions. The effects of mix show significant changes in the geotechnical and mechanical properties of BC soil. Research shows that swelling features reduces alters into non-swelling soil. The soil transitions from a plastic to a brittle state. The results revealed that MDD, UCS, CBR and STS increases significantly with curing periods. The mineralogical and microstructural test carried out using XRD and SEM, which supports the creation of cementitious complex and development of a dense matrix. The results state that utilized binder to stabilize BC soil is suitable for civil infrastructure specially pavement and foundations.

Rammed earth (RE), an ancient construction technique, is a sustainable technology that consumes less energy and is eco-friendly. RE is brittle in nature and fails because of the increase in flexural stresses. Mechanical properties such as strength in compression and tension should be enhanced to reduce brittleness and tensile failure. This study focuses on exploring the relationship between the compressive and tensile strengths of glass fiber-reinforced, bagasse ash (BA)-cement stabilized RE. The experimental investigation lays emphasis on the effect of glass fiber on RE along with BA. The strength in compression of the cement stabilised RE increased by 31% when 0.4% glass fiber of length 12 mm was added, and it further increased by 40% by the addition of 2% BA. Peak strain at peak compressive strength enhanced by 35% with the incorporation of fibers, enhancing ductility while reducing brittleness of RE. The SEM image justifies the addition of BA; it can be observed that the addition led to the reduction of voids, resulting in an increase in the compactness of soil particles in the RE. From the study, it is observed that the regression models that best fit the data were studied and a power regression model gives the goodness of fit and to be used to find the relationship between tensile and compressive strength. The error analysis in comparison to past research suggests a way to consider mix variations to develop regression equations for higher correlation considering different types of fibers.

Sugarcane bagasse ash is a kind of agricultural waste with a large quantity and good volcanic ash reactivity, it is necessary to find a way to reasonably utilize it to prevent environmental pollution caused by long-term accumulation. In this paper, the effect of sugarcane bagasse ash on the short-term mechanical properties of coastal cement soil were studied, and unconfined compressive tests and triaxial shear tests were carried out. The sugarcane bagasse ash content was set to 0 %, 1 %, 2 %, 3 %, 4 % and 5 %, respectively, the cement content was set to 5 %, and the curing age was set at 7d. The test results show that sugarcane bagasse ash can effectively improve the unconfined compressive strength and triaxial shear strength of cement soil, exhibiting a trend of increasing first and then decreasing with the increase of its content. When the sugarcane bagasse ash content is 1 %, the unconfined compressive strength reaches the maximum value of 2040 kPa, which is 56 % and 8 % higher than that of cement soil with 5 % and 7 % cement content, respectively. Compared with cement soil with 5 % cement content, the triaxial shear strength increases by 12 %similar to 17 %, the internal friction angle phi and cohesion c increases by 3 %similar to 8 % and 2 %similar to 11 %, respectively. The SEM test results show that the addition of bagasse ash can promote the hydration of cement to produce hydrated calcium silicate and other hydration products, fill the internal pores of the sample, and make the microstructure of the modified cement soil tend to be dense. The research results provide a reference for the application of sugarcane bagasse ash modified cement soil in practical engineering.

Expansive soils can cause large-scale damage to the infrastructure. Soil stabilization with Portland cement and lime has been widely utilized as a solution to this problem. However, these stabilizers are non-renewable and energy-intensive. Alkali-activated binders are alternatives with lower carbon dioxide emissions. This research evaluated an expansive soil stabilization with an alkali-activated binder produced from sugarcane bagasse ash (SCBA), hydrated eggshell lime (HEL) and sodium hydroxide (NaOH). Free-swelling tests alongside a statistical analysis evaluated the influence of dry unit weight (12.5 and 14.5 kN/m(3)), binder (4 and 10%) and moisture content (19.7 and 24.7%) and curing time (0 and 7 days) on the stabilized mixtures. A four factors factorial design with duplicates and central points was outlined. To better understand the NaOH and SCBA influence over the soil expansion additional tests were performed. In general, an increase on the studied factors reduced swelling, especially binder content. However, the alkali-activated cement presented no clear correlation between higher density and higher expansion. Swell reduced from 13.8% (12.5 kN/m(3) and 19.7% moisture) and 8.8% (12.5 kN/m(3) and 24.7% moisture) to 2.5% and 0%, respectively, after 7 days and 10% binder addition for the alkaline cement. For Portland cement, swell reduced from 13.8% (10.2 kN/m(3) and 22.5% moisture) and 12.5% (10.2 kN/m(3) and 27.5% moisture) to 1.8% and 1%, respectively, after 7 days and 4% binder addition. Samples containing NaOH expanded less than samples molded with only water. Finally, the alternative binder might be a viable option to replace Portland cement for expansion control.

Soft to medium clay soil possesses major sources of damages to the pavement layers overlying them because of their potential failure under moisture changes and external heavy traffic load. In such situations, soil stabilization methods can be used to improve the soil properties and satisfy the desired engineering requirements. This study presents the use of sugarcane bagasse ash (SBA) and lime as chemical stabilizers for a clay soil subbase. Sugarcane bagasse ash and lime are used individually and as mixtures at varying percentages to stabilize a clay soil from Taxila, Pakistan. Various geotechnical laboratory tests such as Atterberg limits, compaction test, and California Bearing Ratio (CBR) are carried out on both pure and stabilized soils. These tests are performed at 2.5%, 5%, and 7.5% of either SBA or lime by weight of dry soil. In addition, mixtures of lime and SBA in ratios of 1:1, 2:1, 3:1, 1:2, and 1:3 are used in 5%, 7.5%, and 10% of dry soil weight, respectively. Results indicate that soil improved with 7.5% SBA showed a 28% increase in the liquid limit, while soil mixed with 2.5% lime in combination with 7.5% SBA showed an increase of 40% in the plastic limit. For the plasticity index, the soil mixed with 7.5% SBA showed an increase of 42%. Moreover, 2.5% lime in combination with 2.5% SBA showed the best improvement in soil consistency as this mixture reduced the soil plasticity from high to low according to the plasticity chart. Furthermore, 2.5% SBA in combination with 5% lime demonstrated the largest improvement on the CBR value, which is about a 69% increase above that of the pure soil. Finally, the cost analysis indicates a promising improvement method that reduces pavement cost, increases design life, and mitigates issues of energy consumption and pollution related to SBA as a solid waste material.

Soil stabilization is critical in construction, impacting the stability and longevity of infrastructure. Traditional materials such as cement, lime and fly ash have long been used for this purpose. Previous research has demonstrated the effectiveness of cement and lime for stabilizing clayey soils. This study builds on that foundation by investigating the innovative use of sugarcane bagasse ash (BA), an agricultural by-product, as a sustainable alternative for soil improvement. BA and lime were added to clayey soil in varying proportions (0%, 4%, 8% and 12% by dry weight) to assess their impact. Geotechnical tests, including Proctor compaction, unconfined compressive strength (UCS) and California Bearing Ratio (CBR) tests, were performed on both unstabilized and stabilized soil samples, with each test repeated three times for accuracy. The results showed that adding BA and varying lime contents significantly improved the soil's maximum dry density (MDD) and UCS, with specific mixtures yielding peak values. The UCS of the stabilized soil increased by 300% to 400% compared to unstabilized soil, while CBR values improved by 61.32% in soaked conditions and 50% in unsoaked conditions. These enhancements suggest that BA and lime mixtures can effectively improve the performance of clayey soils in construction, potentially reducing dependence on conventional materials. The chemical interaction between lime and BA likely contributes to this improvement through pozzolanic reactions, forming cementitious compounds that enhance soil strength and stability. Of all the combinations, the combination of 8% BA and 12% lime provided the greatest improvements in MDD, optimum moisture content (OMC), CBR and UCS. This research not only addresses environmental concerns regarding waste disposal but also aims to optimize soil properties, contributing to safer, more durable infrastructure while promoting sustainability.

On Earth, there is an abundance of soil that has been utilized to build homes for millions of people. Manufacturing compacted stabilized adobe blocks requires adequate water added to the appropriate soil type that has been admixed with binders and fibers to attain maximum density. The mixture is then compressed using the appropriate adobe-forming machine. Currently, the major environmental and human health risks worldwide come from industrial and agricultural wastes because of disposal concerns. The production and use of cement and cement blocks bring numerous economic and environmental issues. Utilizing locally available resources and enhancing standard production and testing methods are two feasible options for sustainable growth. Researchers have seen the promise of earthen construction as an alternative building material, and it is becoming more popular in the context of sustainable development. Marble dust (MD) (Industrial waste), sugarcane bagasse ash (SBA), and paddy straw fiber (PSF) (Agricultural wastes) were utilized in this research to manufacture the unfired admixed soil blocks. This study utilizes marble dust composed up to 25%-35%, paddy straw fiber constituted 0.8%-1.2%, and bagasse ash made up 7.5%-12.5% of the soil. The marble-dust-bagasse-ash-soil mix was strongly adherent to PSF, according to SEM investigation. In addition, as is apparent from the image, the number of pores is insignificant. These images support the preceding conclusions regarding this sample's increased flexural and tensile strength. The primary constituents discovered on the surface of an unfired ad-mixed soil block strengthened with PSF of length 75 mm were silica (Si) and oxygen (O), according to the EDS examination. Aluminum (Al) and magnesium (Mg) were found in trace amounts. The endurance characteristics of the block were determined by conducting different tests on the eighty-one (81) design mixes of the produced unfired ad-mixed adobe blocks, followed by modeling, optimization and microstructural analysis. The results show that the recommended technique improves the durability characteristics of admixed soil blocks without burning better than burnt bricks.