Cement and Superabsorbent Polymer to Solidify Slurry-Paper

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The study evaluates whether superabsorbent polymer (SAP) and cement can solidify high-water-content HydroVac slurry for potential reuse as backfill. The slurry, with an initial water content of about 95%, was mixed with varying cement and SAP dosages and tested for unconfined compressive strength (UCS) and compressibility. UCS specimens were cured for 7 or 28 days; constant-rate-of-strain consolidation tests examined samples cured for 7 or 14 days.<br /><br />UCS generally increased with cement dosage and curing time. SAP also improved strength at suitable dosages: the strongest results occurred with 0.6–0.8% SAP, while excessive SAP weakened particle bonding. The study identifies approximately 10% cement and 0.6–0.8% SAP, by wet slurry weight, as the optimum combination for the tested material. The authors suggest that water held in SAP supports cement hydration, but too much SAP can weaken the mixture.<br /><br />Consolidation testing showed that treated slurry had low rebound after unloading and high yield strength, with yield strength generally increasing with curing time. SAP raised yield strength in some mixtures, though the relationship with dosage was not linear. Overall, the results indicate that cement and SAP can rapidly solidify slurry and produce material with properties that may suit compacted backfill. Further comparisons with conventional backfill materials are needed to establish its field performance.

Keywords

superabsorbent polymer

cement solidification

HydroVac slurry

high-water-content slurry

unconfined compressive strength

compressibility

backfill reuse

cement hydration

yield strength

consolidation test