This research examines the influence of blast furnace slag (BFS) on the physico-mechanical properties of compressed earth blocks (CEBs) stabilised with cement and/or lime. A three-factor mixture design is employed to assess the effects of BFS, cement and lime on key properties such as dry density, water content and compressive strength at 28 and 90 days. The study maintains a constant dune sand proportion with soil substitutions up to 20% (420 grams), while the BFS, lime and cement proportions vary with soil substitutions up to 15% (315 g). The findings indicate that mixtures with over 7.5% cement and equal proportions of lime and BFS, as well as a ternary mixture of 10% cement, 2.5% lime and 2.5% BFS, deliver superior strength. Notably, the optimal compressive strength with a high desirability score of 0.93 is achieved using around 14% cement and 1% lime. Proctor curve analysis shows that BFS-cement-lime substitution reduces water content and increases dry density. Statistical analysis confirms the model's robustness in predicting compressive strength, supported by high F-values and low probabilities, and highlights its effectiveness in guiding design decisions. Additionally, the study's evaluation of rupture types offers further insights into material strength and validates adherence to testing standards.

Addressing loess salinisation is a crucial element in preserving ecological stability and fostering sustainable development in the northwest Loess Plateau. To investigate the impacts of salt solution on the properties of loess, independently designed salt solution-loess dynamic cyclic erosion equipment was used to soak the loess. Then, numerous tests were performed to analyse the variability of the effects of salt solution concentrations (SSC) and type, as well as the duration of soaking time, on these physico-mechanical properties. The results demonstrated that after being soaked in two different types of salt solutions for 3 days, the shear strength index of loess preliminary decreased and then increased. The compressibility preliminary increased and then declined when the SSC increased. After a 7-day soaking period, the cohesion of the loess did not change considerably, whereas the internal friction angle increased in proportion to the SSC. The compression of loess tended to initially decrease, subsequently increase, and eventually decrease. Loess can be slowed down in its disintegration process by salt solution, and disintegration duration can be effectively shortened with a prolonged soaking time. Finally, it is examined the evolutionary process of the impact of salt solution on loess microstructure. Moreover, the exchange of clay minerals with iron and aluminium ions is proposed to be the key element determining the water-loess chemical interaction. This study may function as an insightful guide for preventing and treating salinised loess on the Loess Plateau of Northwest China, while also serving as a reference for similar areas worldwide.

Red clay as a special soil has a high liquid-plastic limit, water swelling and water loss shrinkage. To solve the problems red clay was modified by calcium carbonate produced in Hezhou, Guangxi. The Liquid-plastic limit, water loss shrinkage, nuclear magnetic resonance (NMR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and consolidated drained (CD) triaxial shear test were carried out on the modified soils. The results show that when the calcium carbonate content is 20%, the plastic limit is 24.38 and the liquid limit is 38.67, which are reduced by 35.04% and 22.16%, respectively. The Montmorillonite content in the modified soil is reduced by 27.7%. The shrinkage coefficient decreased from 0.325 to 0.102. The NMR test shows that the content is 5% and 10% would lead to a decrease in the macropores and an increase in the micropores pores. The phenomenon is the opposite (15% and 20%). All contents led to the porosity increase. The calcium carbonate content of 5% was selected for triaxial shear tests to obtain the stress-strain curves. The Duncan-Zhang was used to predict the modified soil. The model has a large error in the prediction of the peak of the principal stress difference, but the overall trend is relatively consistent. Therefore, the correction coefficient related to the confining pressure was introduced. The corrected model fits the triaxial shear test well. The research provides a method for the liquid-plastic limits and shrinkage properties of modified red clay, explores the influence of calcium carbonate content on microscopic pores, and the correction of the model provides a theoretical basis for practical application.

The present project deals with the production of lateritic soil based bricks under different curing temperatures (28 degrees C-150 degrees C). A fraction of 10-30 wt% amount alkaline solution was added to improve the reactive phase content. The raw materials and hardened products were characterized using X-ray diffraction (XRD), fourrier transform infrared spectroscopy (FTIR), mechanical properties and scanning electron microscope analysis. The results show that the addition of alkaline solution (30%) and the curing temperature (150 degrees C) have a beneficial influence on physical properties (bulk density: 1.77 g/cm3, water absorption: 16.98%, and porosity: 30.13%) and mechanical performances (flexural: 6.61 MPa and compressive: 13.57 MPa). Compared with the code requirements for stabilized earth blocks, the compressive strength was higher than the minimum required. Microstructural investigations were also carried out to confirm the macrostructural properties. The above-mentioned process appears to be a suitable candidate for engineering applications such as the stabilization of earth roads. The present project deals with the production of lateritic soil based bricks under different curing temperatures (28-150Acirc;degrees C). A fraction of 10-30 wt% amount alkaline solution was added to improve the reactive phase content. Compared with the code requirements for stabilized earth blocks, the compressive strength was higher than the minimum required. image

Foam lightweight soil (LS) is a cement composite with excellent lightness, but the excessive use of cement causes some negative impacts on the surrounding environment. This study aims to develop a sustainable cement composite by utilizing fly ash and waste soil in LS, providing a practical reference for green construction of road engineering. The physico-mechanical properties of cement composites with different mixing ratios were comparatively evaluated using geotechnical tests, and the micro-mechanisms were investigated using microscopic tests. The testing results showed that the utilization of fly ash and waste soil was unfavorable to improve the mechanical strength and the damage resistance of LS, but significantly decreased the use of cement. The comprehensive performance of cement composite reached the optimum when the replacement rates of fly ash and waste soil were 10% and 20%. Fly ash reacted with the hydration products of cement producing more cementitious gels to make the internal structure of cement composite denser, while waste soil not involved in its chemical reaction. The life cycle assessment indicated that the potential environmental impact of LS was improved after utilizing fly ash and waste soil, and the proposed sustainable cement composite had good feasibility in engineering.

The soft soil of Long Phu thermal power plant in Soc Trang province of southern Vietnam was treated by the PVD incorporating surcharge and vacuum preloading method. To evaluate the effectiveness of this method, experimental in-situ research combined with laboratory tests were performed on soft soil before and after tests, undrained unconsolidated compression (UU) and undrained consolidated (CU) triaxial tests. The insitu tests included static penetration tests, static penetration tests with measurement of pore water pressure (piezocone penetration tests), vane shear tests, and standard penetration tests. Based on experimental results, this article evaluated the changes in the physical and mechanical properties of soft soil. The experimental results indicated that the soil after improvement increases shear strength and decreases compression. The relationship between the physico-mechanical properties of soft soil and improved soil was established. It has shown the success of the improvement of soft soil by PVD' incorporating surcharge and vacuum preloading in Vietnam.