Case Study: The Effects of Hot Temperatures on Deep Mix Method Seepage Barrier Construction

This paper presents a case study of hot weather impacts on cementitious cutoff wall seepage barrier construction. For a recent Sacramento River project, Deep Soil Mixing (DSM) Deep Mix Method (DMM) was deployed which uses a grout slurry mixture of Portland cement, bentonite, and water. Slurry is injected into the ground and mixed with the surrounding soil creating a soil-cement-bentonite cutoff wall. Specifications for maintaining the grout mixture under 90°F were developed with concern for the potential negative effects on strength and permeability of the cutoff wall. Cement grout applications are typically required to adhere to American Concrete Institute (ACI) code and ASTM standards. However, there are no applicable codes that fully address the use of cement in seepage barrier cutoff walls. The data obtained from this case study does not support the need for temperature control requirements of soil-cement-bentonite grout mixtures during construction.