As a technical sales representative who has over 44 years of experience with drilling fluids and over 20 years of expertise in the foundation drilled shaft industry, I believe that transportation departments should be more frequently qualifying the use of synthetic slurry for foundation drilled shafts. Synthetic slurry can offer significant benefits over current, and sometimes costly, methods.
A foundation drilled shaft, or caisson, is a circular excavation constructed and designed to support structures like large buildings, bridges or overpasses. After the shaft is drilled (ideally down to solid bedrock), a steel reinforcement cage is installed and concrete poured to fill the shaft from the bottom up, displacing the slurry to create a caisson.