Showing 2 results for Bentonite
N Shariatmadari, M.mehdi Yazdanpanah, Saeid Saeidijam,
Volume 8, Issue 3 (12-2014)
Abstract
Saline sea water, groundwater into salt domes or municipal waste leachate can affect hydro-mechanical properties of bentonite as a sealing material in nuclear waste repositories or landfills. This paper investigated the effect of sodium chloride solution on Atterberg’s limit, swelling, consolidation and permeability of bentonite. Swelling and consolidation test had been done at 0.05, 0.1, 0.5 and 2 molar solution and pure water by oedometer apparatus in Iran University of Science and Technology. Considering the results, it can be seen that a little increase in concentration of the solution reduces swelling of bentonite. So that the swelling potential of bentonite reduced from about 82% to about 1.5% by increasing in concentration of the solution from pure water to 2 molar solution. Liquid limit and plastic index of bentonite were reduced by increasing concentration of the solution but plastic limit was not changed significantly. Meanwhile increased concentration of the solution will facilitate reaching equilibrium for swelling and consolidation of the samples which occur due to their enhanced permeability. Permeability of bentonite increased about 7 times by increasing in concentration of solution from pure water to 2 molar solutions. Also, the Compressibility of bentonite was reduced by increasing in concentration of sodium chloride in the solution.
Maryam Hadi, Rasol Ajalloeian, Amir Hossein Sadeghpour,
Volume 8, Issue 3 (12-2014)
Abstract
One way of reduction of leakage from beneath of earth dams is using of one contact clay layer with very low permeability and intermediate to high plastisity and connectig it to core of dam. Since, most of fine-grained soil in environtment of dam have low plastisity and preparing it from another place is not economic, use of bentonite in order to improvement of engineering characteristic of borrowed clay is suitable way.
In this search effect of bentonite on geotechnical properties of fine-grained soils with low plastisity are evaluated. Results of this research show that hydraulic conductivity, consolidation coefficient, dry density, colifornia bearing ratio (CBR),.....are decreased with increase in bentonite content but optimum moisture , Aterberg limits , cohession and so on are increased with bentonite addition. Finally, with analysis of obtained result, optimum percent of bentonite is offered in order to improve of engineering properties of used clay in contact region.
