High-plasticity soils such as alluvial clay deform easily under heavy loads due to their strong plastic behavior. The tendency of these soils to expand and contract can cause deformation and cracking in structures, posing challenges in construction. To address these challenges, it's essential to improve these soils to enhance their strength and reduce plasticity before construction. Therefore, this study aims to evaluate the applicability of marble dust as a sustainable alternative to Portland cement in ground improvement applications, specifically to improve the behavior of alluvial clay. The performance of marble dust, Portland cement, and alluvial clay mixtures was evaluated using unconfined compressive strength (UCS), shear wave velocity, and mass loss due to weathering. The study tested three Portland cement contents (7, 10, and 13 %), two dry density (1.6 and 1.8 g/ cm3), and two marble dust contents (0, 10 and 20 %) across three curing ages (7, 28, and 60 days). Micro- structural analysis was performed using SEM. Results indicated a slight decrease in 7-day strength (up to 8.3 %) with 10 % marble dust replacement due to minimal pozzolanic activity, while 28-day strength loss was less significant. On the other hand, the 60-day strength increased up to 20 % upon replacing 10 % of cement with marble dust. The marble dust addition also increased the shear modulus of the soil by up to 9 % when compared with cement only. The adjusted porosity index of 0.32 correlated unconfined compressive strength (qu), initial shear modulus (G0), and accumulated loss of mass (ALM) across varying densities and blend proportions. ALM increased linearly with wet-dry cycles, with higher compaction and binder content reducing mass loss per cycle. More marble dust, however, led to greater mass loss at both curing ages, attributed to reduced cement content.

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.