The present paper discusses the hydro mechanical behavior of activated Ca–bentonite mixed with two solublepolyelectrolyte powder polymers. To understand better the clay polymer interaction, swelling, water adsorptionand hydraulic performance are studied. Synthetized leachate (LS) is used to reproduce the hydrochemical phenomenain the system. Hydraulic performance tests were performed with an oedopermeameter and modifiedAPI filter press. Both methods gave the similar bentonite material behaviors and classification order, showingthat polymers are reducing the permeability, in contact with the LS. Water adsorption and free swell index testsresults have confirmed that (1) adsorption, swelling and permeability parameters are linked for clay polymermixtures and (2) the polymers could improve the overall clay properties. Each polymer has a different effect:the anionic polymer induces a low permeability to the mixture; the cationic polymer makes the bentonite moreswellable, with high ability to retain water and to become more resistant to the LS. Laboratory tests resultsdemonstrate that the behavior of bentonite polymer mixtures for landfill liner applications depends essentiallyon the nature of the surface charge of the polymer.
