Polymer applications to control soil expansion

MAURO CODEVILLA; MARIANO TOMAS FERNÁNDEZ; DIEGO MANZANAL; TERESA MARÍA PIQUÉ

Belo Horizonte

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

ABMS

The purpose of this study is to evaluate the efficiency of different soil-polymers mixtures to control natural soil expansion. This work is part of an ongoing research project carried out at the School of Civil Engineering at Buenos Aires University. The soil-polymer mixtures were carried out with expansible high plasticity clay from Comodoro Rivadavia (Argentina). The clay exhibits plastic volumetric behavior over a wide range of moisture contents. Damages on light buildings caused by soil expansion were reported many times at the site (Orlandi et al, 2015, 2016). Its physical and mechanical characterization was done on earlier works (Marti et al., 2015). In this research, soil was stabilized with four types of polymers: Calcium lignosulfonate, Cationic Polyacrylamide (CPAM),Anionic Polyacrylamide (APAM) and starch. To assess the impact of the polymer quantity within mixtures, three weight proportions were tested: 1.5, 3.0 and 5.0 % by weight of clay. The research was divided in two stages. Firstly, physical and mechanical characterization was carried out for all mixtures to determine polymer modifications and its proportion influence in controlling soil expansion. Finally, hydro-mechanical characterization of the selected mixture was performed: water retention curve was obtained and free swelling-swelling pressure tests were carried out. The attenuation of the expansion potential for the different percentage of four polymers is discussed. Results are presented in terms of variation on index properties, the effects of the polymer in the potential expansion of the soil and the relationship of suction-degree of saturation. The hydraulic and mechanical behavior presented significant changes in comparison to the unmodified clay.