improving soil engineering properties is an inevitable process before construction on soft soil. increasing soil strength with chemical stabilizing agents, such as cement, raises environmental concerns. therefore, sustainable solutions are in high demand. one of the promising solutions is the usage of biopolymers. Five biopolymer types were investigated in this study: Xanthan Gum, Beta 1,3/1,6 Glucan, Guar Gum, Chitosan, and Alginate. Their effect on the soil strength improvement was experimentally investigated by performing unconfined compression, splitting tensile, triaxial, and direct shear tests. All tests were performed with different biopolymer concentrations and curing periods. Additionally, in order to have an insight on the susceptibility to natural elements, plain soil, and biopolymertreated specimens were exposed to real atmospheric conditions. The extensive experimental results showed that the soil strength tends to increase with the increase of biopolymer concentration and with the curing time. However, it was shown that the soil strength does not considerably change after a certain biopolymer concentration level and curing time. furthermore, it has been observed that the biopolymer-treated specimens showed better resistance to the influence of the environmental conditions. In general, Xanthan Gum, Guar Gum, and Beta 1,3/1,6 Glucan showed the most dominant effect and potential for the future of sustainable engineering.

When construction work is planned on soil with inadequate shear strength, its engineering properties need to be improved. Chemical stabilization is one of the solutions for soil strength improvement. Currently, the most common additive that is used for chemical soil improvement is cement. Cement is an effective solution, but it has several negative effects on the environment. Therefore, the urges for environment-friendly solutions that can replace cement and show good potential for sustainable engineering are rising. One of the promising environment-friendly solutions is the use of biopolymers. Therefore, the main aim of the present study was to investigate the effect of the biopolymer xanthan gum on the strength of different types of soil. Xanthan gum was mixed with three different types of soil: sand, clay, and silty sand. The strength of treated and non-treated soil was experimentally investigated by performing unconfined compression, direct shear, and triaxial tests. From the results, it was observed that xanthan gum significantly increased the strength of each soil, which shows its major potential for the future of sustainable engineering.

No abstract

No abstract

Desiccation cracking of cohesive soils is the development of cracks on the soil surface as a result of a reduction in the soil moisture content. The decrease in soil surface area owing to the desiccation of cohesive soils has an undesirable impact on the mechanical, hydrological, thermal, and physico-chemical properties. Many efforts have been made to improve the desiccation crack resistance of cohesive soils, but the current solutions raise a number of environmental issues, increasing the demand for sustainable soil improvement alternatives. Therefore, the main objective of this study is to investigate novel eco-friendly soil improvement techniques, such as recycled carpet fibers and a gelatin-based bioplastic, and their effect on desiccation cracking in cohesive soils. The improvement of soil crack resistance was studied by conducting desiccation cracking tests on plain and improved soils. In addition, image processing was conducted to quantitatively describe the effect of soil improvement type on the geometrical characteristics of crack patterns. Each soil improvement technique enhanced the soil strength and reduced cracking at room temperature, at an elevated temperature, and when subjecting to cyclic wetting and drying. The addition of bioplastics proved to be the most effective solution, thus demonstrating a viable option to advance future sustainable engineering practices.

No abstract

No abstract

The world today is more oriented towards sustainable and environmental-friendly solutions in every field of science, technology, and engineering. Therefore, novel sustainable and eco-friendly approaches for soil improvement have also emerged. One of the effective, promising, and green solutions is the utilization of biopolymers. However, even though the biopolymers proved to be effective in enhancing the soil-mechanical properties, it is still unknown how they behave under real environmental conditions, such as fluctuating temperatures, moisture, plants, microorganisms, to name a few. The main research aim is to investigate the durability of biopolymer-improved soil on the cyclic processes of wetting and drying. Two types of biopolymers (Xanthan Gum and Guar Gum), and two types of soils (clean sand and silty sand) were investigated in this study. The results indicated that some biopolymer-amended specimens kept more than 70% of their original mass during wetting-drying cycles. During the compressive strength analysis, some biopolymer-treated specimens kept up to 45% of their initial strength during seven wetting-drying cycles. Furthermore, this study showed that certain damaged soil-biopolymer bonds could be restored with proper treatment. Repeating the process of wetting and drying can reactivate the bonding properties of biopolymers, which amends the broken bonds in soil. The regenerative property of biopolymers is an important feature that should not be neglected. It gives a clearer picture of the biopolymer utilization and makes it a good option for rapid temporary construction or long-standing construction in the areas with an arid climate.