Proposed Improvements to Laboratory Testing Programs For The Design Of Self-Hardening Slurry Cutoff Walls-Video

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Video Summary

The presentation proposes improving laboratory testing of self-healing slurry used in cutoff walls so results better reflect field conditions. Current tests often rely on short-term curing and inconsistent mixing, fluidity, and additive dosages, which can distort predictions of strength and permeability.<br /><br />Recommendations include using fresh, site-relevant materials; checking soil and groundwater chemistry; measuring slurry viscosity and gel strength over time; and reproducing field mixing procedures, temperatures, and equipment effects. Filtration testing should use more realistic pressures and durations rather than standard API conditions. Testing should also examine gel strength’s effect on suspended solids and assess properties after at least six months—preferably a year—because earlier results are transient.<br /><br />The speaker also calls for engineers to specify the loads materials must withstand, rather than relying on arbitrary strength measures. Finally, permeability tests should use gradually increasing hydraulic gradients to determine whether a threshold exists below which water does not flow through the wall.

Keywords

self-healing slurry

cutoff walls

laboratory testing

permeability testing

gel strength