This laboratory study examines the potential use of an anionic polyacrylamide(PAM)-based material as an environmentally sustainable additive for the stabilization of an expansive soil from South Australia.The experime...This laboratory study examines the potential use of an anionic polyacrylamide(PAM)-based material as an environmentally sustainable additive for the stabilization of an expansive soil from South Australia.The experimental program consisted of consistency limits,sediment volume,compaction and oedometer cyclic swell-shrink tests,performed using distilled water and four different PAM-to-water solutions of P_(D)=0.1 g/L,0.2 g/L,0.4 g/L and 0.6 g/L as the mixing liquids.Overall,the relative swelling and shrinkage strains were found to decrease with increasing number of applied swell-shrink cycles,with an‘elastic equilibrium’condition achieved on the conclusion of four cycles.The propensity for swelling/shrinkage potential reduction(for any given cycle)was found to be in favor of increasing the PAM dosage up to P_(D)=0.2 g/L,beyond which the excess PAM molecules self-associate as aggregates,thereby functioning as a lubricant instead of a flocculant;this critical dosage was termed‘maximum flocculation dosage’(MFD).The MFD assertion was discussed and validated using the consistency limits and sediment volume properties,both exhibiting only marginal variations beyond the identified MFD of P_(D)=0.2 g/L.The accumulated axial strain progressively transitioned from‘expansive’for the unamended soil to an ideal‘neutral’state at the MFD,while higher dosages demonstrated undesirable‘contractive’states.展开更多
基金funded by the Australian Research Council(ARC),Project No.DP140103004。
文摘This laboratory study examines the potential use of an anionic polyacrylamide(PAM)-based material as an environmentally sustainable additive for the stabilization of an expansive soil from South Australia.The experimental program consisted of consistency limits,sediment volume,compaction and oedometer cyclic swell-shrink tests,performed using distilled water and four different PAM-to-water solutions of P_(D)=0.1 g/L,0.2 g/L,0.4 g/L and 0.6 g/L as the mixing liquids.Overall,the relative swelling and shrinkage strains were found to decrease with increasing number of applied swell-shrink cycles,with an‘elastic equilibrium’condition achieved on the conclusion of four cycles.The propensity for swelling/shrinkage potential reduction(for any given cycle)was found to be in favor of increasing the PAM dosage up to P_(D)=0.2 g/L,beyond which the excess PAM molecules self-associate as aggregates,thereby functioning as a lubricant instead of a flocculant;this critical dosage was termed‘maximum flocculation dosage’(MFD).The MFD assertion was discussed and validated using the consistency limits and sediment volume properties,both exhibiting only marginal variations beyond the identified MFD of P_(D)=0.2 g/L.The accumulated axial strain progressively transitioned from‘expansive’for the unamended soil to an ideal‘neutral’state at the MFD,while higher dosages demonstrated undesirable‘contractive’states.
