Abstract:
The USACE Sacramento District covers a wide geographical area including an array of flood protection levees that need improvements. A program of cutoff walls construction involving a variety of techniques has been active since the early 80’ s. After a number of iterations, the single-phase self-hardening slurry cutoff wall has been assessed as a more engineered technique offering high levels of QC/QA. The District has made commendable efforts, almost single-handedly in the country to better understand this technology. Improved design and specifications have resulted. Ground Blast Furnace Slag Cement (Slag cement) has made significant inroads over the last decades in the formulation of self-hardening slurries commonly referred as cement bentonite or CB. Bentonite clay has been the only official clay to be used as a stabilizing agent for suspending the cementitious binder. Where bentonite is generally the best choice for soil bentonite cutoff walls, its predominant role self-hardening slurry cutoff wall may be challenged by other clays widely available in the US. From the present state of experimentation, a wider field of research in the laboratory is proposed to achieve a better correlation between laboratory and field tests results while exploring alternate formulations leading to a better end-product.