The effect of biopolymers on the soil strength
Abstract
Cement is an effective and common way to increase the soil strength, but its negative effect on the environment led to the search for environmentally friendly alternative solutions. One of the most promising solutions are biopolymers. Biopolymers are nature-made large molecules that tend to increase the soil strength when mixed with it. Therefore, the main objectives of this research were to develop eco-friendly, biopolymer-based soil improvement methods, and to investigate their effect on the strength behavior of soil. To date, five different types of biopolymers were used to achieve those objectives: xanthan gum, guar gum, beta 1,3/1,6 glucan, chitosan and alginate-calcium chloride solution. Their effect on the soil strength improvement was investigated numerically and experimentally (unconfined compression, indirect tensile and triaxial tests). Experiments were performed on plain soil and on the biopolymer-reinforced soil. The additional variables that were considered were the percentage of biopolymers added to the soil and the specimen curing time. Furthermore, to represent the elastic-plastic behavior to obtain a stress-strain response of biopolymer-modified soil a non-linear, non-associated Drucker-Prager hardening plasticity model was used. Several real uniaxial compression tests on soil with and without biopolymer addition were modeled numerically. In most of the cases, soil specimens with the addition of biopolymers showed higher strength than the specimens that did not have additives. These findings agreed well with the experimentally observed response. Furthermore, xanthan gum proved to have the highest impact on the soil-strength improvement and it has a great potential to be the leading biopolymer for soil improvement.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFMNS13C0607S
- Keywords:
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- 0416 Biogeophysics;
- BIOGEOSCIENCESDE: 0418 Bioremediation;
- BIOGEOSCIENCESDE: 0419 Biomineralization;
- BIOGEOSCIENCESDE: 1835 Hydrogeophysics;
- HYDROLOGY