This study investigates the sustainable use of seabed dredged sediments and water treatment sludges as construction materials using combined dewatering and cement stabilization techniques. Dredged sediments and water treatment sludges, typically considered waste, were evaluated for their suitability in construction through a series of dewatering and stabilization processes. Dewatering significantly reduced the initial moisture content, while cement stabilization improved the mechanical properties, including strength and stiffness. The unconfined compressive strength (UCS), shear modulus, and microstructural changes were evaluated using various analytical techniques, including unconfined compression testing, free-free resonance testing, X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). The results show a direct correlation between reduced w/c ratios and increased UCS, confirming the potential of treated sludge as a subbase layer for roads and landfill liners. A chemical analysis revealed the formation of calcium silicate hydrate (CSH) and ettringite, which are critical for strength enhancement. This approach not only mitigates the environmental issues associated with sludge disposal but also supports sustainable construction practices by reusing waste materials. This study concludes that cement-stabilized dredged sediments and water treatment sludges provide an environmentally friendly and effective alternative for use in civil engineering projects.

This study explores the efficacy of Natural Rubber Latex (NRL) as an additive in enhancing the mechanical properties and durability of cement-stabilized Recycled Concrete Aggregate (RCA) and Lateritic Soil (LS) blends for pavement applications. The research focused on determining the optimal NRL content and evaluating the performance of the stabilized blends under environmental stress represented by wetting-drying (w-d) cycles. Unconfined Compressive Strength (UCS) and Indirect Tensile Strength (ITS) tests were conducted alongside Scanning Electron Microscopy (SEM) to assess the microstructural integrity of the materials. The results demonstrated that the inclusion of NRL at a 5% rubber-to-cement (r/c) ratio significantly improved the initial UCS, ITS, fatigue life, and durability performance of the RCA:LS blends. The 70:30 RCA:LS blend outperformed the 50:50 blend, indicating a composition-dependent response to NRL addition. The findings suggest NRL's potential in sustainable pavement construction, with implications for enhancing strength in stabilized pavement materials.

The extraction and processing of iron ore produce significant amounts of mine tailings, causing environmental problems that require storage in reservoirs or dams. Using these materials in construction helps minimize their adverse impacts. This study analyzed the geotechnical properties of Magnetite and Hematite iron ore tailings (MIOT, HIOT) from the Golgohar mine in Sirjan, Iran. Two IOTs were compacted using the Standard Proctor technique after being treated with 5, 7, and 9 % Portland cement. Following curing time, treated samples were tested at different stress levels for resilient modulus. Based on the results, to meet strength and durability requirements, cement-treated MIOT needs 9 % cement. Contrastingly, only 5 % of the cement for cement-treated HIOT met the criterion. The resilient moduli of untreated MIOT and HIOT materials heavily rely on the confining pressure, resulting in a minimal decrease in modulus by increasing deviatoric stress. The effect of cement on resilient modulus is more pronounced in high confining stresses than in low confining stresses in MIOT and HIOT materials. A comparison of different non-linear models showed that 'Universal' model is the best fit for laboratory results of cement-treated MIOT and HIOT materials, as it accounts for hardening and softening behavior.

Pavement performance is associated with the characteristics of soil sub-grade and underlying layers. The poor soil subgrade and sub-base can deteriorate the overlying upper pavement layers. The weak layers can be improved by stabilization to get the optimum performance of the pavement. The study is abort stabilized base and sub-base soils using ordinary Portland cement 43 (OPC 43). With the variation of cement from 1.5% to 7%, stabilized samples have been treated to have the highest moisture content and dry density possible. An optimization model has been developed for compressive strength using response surface methodology (RSM). The results have been obtained from the model satisfy the real-life field conditions. The outcomes suggest that the cement-stabilized gravels meet the compressive strength criteria specified by the Ministry of Rural Development (MoRD) specifications for rural roads in India.

The cement stabilization techniques have been applied to various types of infrastructure and become one of the essential techniques. A lot of researches have been conducted on the physical and mechanical properties of the cement stabilized soils, many of which are the studies on the stabilized soil after the hydration. However, the number of researches is limited on the physical and mechanical behavior of cement stabilized soil during the hydration stage and subjected to shear deformation during the hydration stage. In this study, a series of direct shear tests was conducted on the shear behavior of cement stabilized soil to investigate the influence of the magnitude and timing of the shearing on the shear behavior. The researche revealed that the shear strength of the stabilized soil is recovered to the peak strength when it is subjected to the shear deformation prior to the peak strength and the shear strength increases by the cement hydration. On the other hand, when the soil is subjected to the large deformation exceeding to the peak strength, the shear strength loss is not recovered in the following shearing stage. The strength gain due to the cement hydration is also influenced by the initial shearing, where the strength of soil subjected to the large shearing remains small for the curing stage. In this manuscript, the test results are introduced to discuss the influence of the initial shearing as well as the testing procedure.