Preliminary results of polymer-enhanced soil mixtures for potential use as covers or liners in landfill systems

Abstract

The use of polymers can change specific properties of natural soils. This study analyses the interaction of a natural fine sand, a clayey soil and anionic polyacrylamide (APAM). The laboratory results show that APAM, a superabsorbent polymer, increases the plasticity and the capacity of water absorption of a clay-APAM and a sand-clay-APAM compacted composite. Free swelling and swelling pressure also increase with addition of APAM. Sand-clay-APAM composite shows a higher uniaxial compressive strength and slight reduction of hydraulic conductivity. Microstructural analysis confirms the aggregation capacity of APAM and a reduction of the accumulated pore volume which minimise liquid infiltration and soil erosion. Results demonstrated that the clay-APAM and a sand-clay-APAM composites can be effective as liners and covers respectively in a landfill system.