A Novel Clean Biopolymer-Based Additive To Improve Mechanical And Microstructural Properties of Clayey Soil [post]

Hasan Ghasemzadeh, Farzaneh Modiri, Ehsan Darvishan
2021 unpublished
Conventional soil additives, as a sector of construction materials, can cause serious environmental problems due to their cement-dependent nature. To eliminate destroying effects of these kinds of additives, environmentally friendly ones have gained great consideration. Although polysaccharides are considered as powerful biocompatible soil additives in recent studies, the effect of their crosslinked hydrogel with elevated rheological and adhesive properties has been very rarely investigated in
more » ... oil stabilization. In this paper, calcium chloride was used as ionic crosslinker to enhance recently proposed Persian gum biopolymer as a novel polysaccharide-based additive for clayey soil stabilization. A group of macro and micro scale tests including unconfined compressive strength (UCS), direct shear test (DS), freeze thaw durability, scanning electron microscopy (SEM), stereo zoom microscopy (SZM), Brunauer, Emmett and Teller (N2-BET) and X-ray diffraction (XRD) were conducted. The tests were also performed on soil treated with xanthan gum as a common hydrocolloid of soil stabilization. As the results show, the introduced ionic crosslinked hydrogel at its optimum content has superior performance than well-known xanthan gum in terms of soil strength and ductility. Crosslinking has also positive effects on durability results of pure Persian gum to make it comparable to xanthan gum. Consumption of lower amounts of Persian gum at presence of ionic crosslinker can make stabilization projects more economical efficient. Microscale tests also confirmed the powerful impact of optimum modified hydrogel on soil interstructure by filling the pores, agglomeration of soil particles and formation of new cementitious compounds in the mineralogical structure of the soil.
doi:10.21203/rs.3.rs-647313/v1 fatcat:ijw65mf6pfesdavvx4qgpvsoyy