Polymer enhanced clay-sand mixture

G. FERNÁNDEZ; C. CASAGRANDE; D. MANZANAL; M. CODEVILLA; PIQUÉ, TERESA M

Cancun

Conferencia; XVI Pan-American Conference on Soil Mechanics and Geotechnical Engineering; 2019

Sociedad Mexicana de Mecánica de Suelos

Using polymers to modify the properties of soils is an area of interest fordesigning landfills. Landfill closures requires conditions of long-term mechanicaland hydraulic stability. This work studies the micro and macroscopic interaction ofa fine soil (CRclay), a uniform sand (Sand) and an anionic polyacrylamide (APAM).APAM is a superabsorbent polymer that swells by two orders of magnitude whenimmersed in water. This paper emphasizes on understanding the interaction betweendifferent mixtures of APAM, Clay and Sand analyzing the physical properties, soilwaterretention, microstructure by means of Mercury Intrusion Porosimetry (MIP),and volumetric and mechanical behaviour. Results shows an increase on swellingpotential and swelling pressure for different Sand-CRclay-APAM mixtures. APAMreduce the microporosity and increase the water retention capacity of the mixtures.For the mechanical behavior, mixtures with APAM present higher unconfinedcompressive strength and more ductile behavior than mixtures without it (Sand-CRclay). The low hydraulic conductivity of the mixtures with APAM make it viablefor its use as part of landfill cover installations.