Intermittent swelling and shrinkage of a highly expansive soil treated with polyacrylamide

This laboratory study examines the potential use of an anionic polyacrylamide (PAM)-based material as environmentally sustainable additive for stabilization expansive soil from South Australia. The experimental program consisted consistency limits, sediment volume, compaction and oedometer cyclic swell–shrink tests, performed using distilled water four different PAM-to-water solutions P D = 0.1 g/L, 0.2 0.4 g/L 0.6 mixing liquids. Overall, relative swelling shrinkage strains were found to decrease with increasing number applied cycles, ‘elastic equilibrium’ condition achieved on conclusion cycles. propensity swelling/shrinkage reduction (for any given cycle) was be in favor PAM dosage up beyond which excess molecules self-associate aggregates, thereby functioning a lubricant instead flocculant; this critical termed ‘maximum flocculation dosage’ (MFD). MFD assertion discussed validated limits volume properties, both exhibiting only marginal variations identified g/L. accumulated axial strain progressively transitioned ‘expansive’ unamended ideal ‘neutral’ state at MFD, while higher dosages demonstrated undesirable ‘contractive’ states.