Polymer applications to control soil expansion

M. FERNANDEZ; M. CODEVILLA; T. PIQUE; D. MANZANAL

Belo Horizonte

Conferencia; XVIII Brazilian Conference on Soil Mechanics and Geotechnical Engineering.; 2016

ABMS

<!-- /* Style Definitions */p.MsoNormal, li.MsoNormal, div.MsoNormal{mso-style-unhide:no;mso-style-qformat:yes;mso-style-parent:"";margin:0cm;margin-bottom:.0001pt;mso-pagination:widow-orphan;mso-layout-grid-align:none;punctuation-wrap:simple;text-autospace:none;font-size:10.0pt;font-family:"Times New Roman";mso-fareast-font-family:"Times New Roman";mso-ansi-language:EN-GB;mso-fareast-language:PT-BR;}.MsoChpDefault{mso-style-type:export-only;mso-default-props:yes;font-size:10.0pt;mso-ansi-font-size:10.0pt;mso-bidi-font-size:10.0pt;mso-ansi-language:ES-AR;}@page WordSection1{size:612.0pt 792.0pt;margin:72.0pt 90.0pt 72.0pt 90.0pt;mso-header-margin:36.0pt;mso-footer-margin:36.0pt;mso-paper-source:0;}div.WordSection1{page:WordSection1;}-->Thepurpose of this study is to evaluate the efficiency of different soil-polymersmixtures to control natural soil expansion. This work is part of an ongoingresearch project carried out at the School of Civil Engineering at Buenos AiresUniversity. The soil-polymer mixtures were carried out with expansible highplasticity clay from Comodoro Rivadavia (Argentina). The clay exhibits plasticvolumetric behavior over a wide range of moisture contents. Damages on lightbuildings caused by soil expansion were reported many times at the site(Orlandi et al, 2015, 2016). Its physical and mechanical characterization was doneon earlier works (Marti et al., 2015). In this research, soil was stabilizedwith four types of polymers: Calcium lignosulfonate, Cationic Polyacrylamide (CPAM),Anionic Polyacrylamide (APAM) and starch. To assess the impact of the polymerquantity within mixtures, three weight proportions were tested: 1.5, 3.0 and5.0 % by weight of clay. The research was divided in two stages. Firstly,physical and mechanical characterization was carried out for all mixtures todetermine polymer modifications and its proportion influence in controlling soilexpansion. Finally, hydro-mechanical characterization of the selected mixturewas performed: water retention curve was obtained and free swelling-swellingpressure tests were carried out.  Theattenuation of the expansion potential for the different percentage of four polymersis discussed. Results are presented in terms of variation on index properties,the effects of the polymer in the potential expansion of the soil and therelationship of suction-degree of saturation. The hydraulic and mechanical behaviorpresented significant changes in comparison to the unmodified clay