Improving saline soils’ properties by incorporating limes is a practical technique, generally due to cation exchange, pozzolanic reaction, and carbonation. This study explores how soil salinity, measured by electrical conductivity, affects untreated and lime-treated saline soils. An Algerian sebkha soil (from Ain M’lila) with an original high salinity (ECe3 = 23.2 dS.m⁻¹) was used. The same soil was washed to create medium (ECe2 = 8.3 dS.m⁻¹) and low (ECe1 = 2.32 dS.m⁻¹) salinity soil samples. The results of this study indicate that salinity influenced the shape of the particle size distribution curve, particularly in the silt range. Salinity also had a significant effect on carbonate content (CaCO₃) and unconfined compressive strength (UCS). For the untreated soil, when salinity decreased, the UCS and CaCO₃ content increased. However, when salinity decreased for the treated soil, the UCS increased, while the CaCO₃ content decreased. X-ray diffraction (XRD) analysis of untreated soils showed halite (NaCl) disappearance and gypsum (CaSO₄ 2H₂O) reduction with decreasing salinity in ECe1. In treated soil at ECe3, these mineral phases remained constant. While XRD detected no new cementitious phases in treated ECe3 or ECe1 samples, thermogravimetric analysis confirmed the presence of portlandite in both. As Ain M’lila sebkha is a chloride–sulfate soil, the dissolution of the halite and gypsum phases released more Cl⁻ and SO₄²⁻ ions into the interstitial solution. In a low fraction of clay, these ions obstructed and slowed the pozzolanic reaction in the ECe3 soil. Identifying the season when this type of soil has lower salinity can be beneficial for treatment from a technical, economic, and environmental point of view.

In the efforts for eco-friendly and affordable substitutes, the construction industry uses recycled waste materials like ceramics and plastic, which can be used as reinforcement filler to address environmental problems from composites. This study is focused on evaluating the feasibility of industrial by-products for improving the properties of mortar using ceramic and plastic waste as partial replacements for cement and sand. The effect of using two wastes on density, compressive and flexural strength, water absorption, ultrasonic pulse velocity and high temperature behavior of mortar were evaluated for the different mortar mixes, as well as characterization analyses, were performed using X-ray diffraction (XRD), thermogravimetric analysis (TGA/DSC), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The findings prove that the heat-insulating capacity of mortar at high temperatures can be significantly increased through a waste ceramic application. Furthermore, the pozzolanic reactivity of the ceramic waste was detected by decreases in portlandite content and variations in hydration products, thermal phases, and mineral phases of the studied mortar, as observed using XRD, TGA/DSC, and FTIR measurements. It was also shown that plastic waste added to ceramic waste can effectively minimise capillary water absorption. This work provides applicable technical and environmental benefits for creating sustainable mortar using this waste.

This study investigates the effects of varying salinity levels on sebkha soils, focusing on their physical, mechanical, and chemical properties. Soil samples were collected from Tin silt sebkha in Ain M'lila across three different seasons, resulting in high salinity soil (HSS), medium salinity soil (MSS), and low salinity soil (LSS). The grain size distribution curves reveal that 70% of grains in both HSS and LSS have diameters less than 60 µm, with LSS containing 19% more particles smaller than 20 µm compared to HSS. Unconfined compressive strength (UCS) measurements show a significant decrease from 1100 kPa in LSS to 200 kPa in HSS, with corresponding peak strains increasing from 2.3% to 4.7%. Chemical analysis indicates that pH decreases from 8.17 in LSS to 6.79 in HSS, reflecting increased soil acidity with higher salinity. SEM images demonstrate that higher salinity results in a denser soil structure due to salt cementation, whereas lower salinity soils exhibit more micropores. The study highlights the need for comprehensive models integrating these properties to enhance predictive capabilities and inform effective soil management. Future research should explore remediation strategies using additives to improve soil strength and stability, addressing the challenges posed by salt dissolution and soil degradation.