Date of Graduation

12-2024

Document Type

Thesis

Degree Name

Master of Science in Civil Engineering (MSCE)

Degree Level

Graduate

Department

Civil Engineering

Advisor/Mentor

Barry, Michelle L.

Committee Member

Murray, Cameron D.

Second Committee Member

Wood, Clinton M.

Keywords

BCSA cement; hole erosion test; piping; shear stress; soil erosion; soil stabilization

Abstract

Levees play a fundamental role in preserving human lives and resources and are the key infrastructure protecting against flood events. In the United States, the levee system is extensive, but unfortunately many of the levees were either not engineered or have well exceeded their intended design life. This was evident after the Midwest floods of 2019, which resulted in the failure of multiple levees leading to costly losses and repairs. In addition, flood levels remained high for days at a time, making it imperative to find fast and effective repair methods. This thesis presents a study conducted at the University of Arkansas in which BCSA (belitic calcium sulfoaluminate) cement was explored as an alternative for rapidly repairing underwater and flood susceptible infrastructure due to its ability to generate high strength in a matter of hours. This research consisted of using a modified hole erosion test (HET) system, called the UARK HET, to evaluate the erodibility of BCSA soil-cement mixtures. The modified system has notable differences from the original HET system by employing a pressurized water supply and flow valve that connects to the upstream chamber, instead of the conventional elevated water tank. In addition, a camera was installed in the downstream chamber for the measurement of the hole diameter in the sample throughout the test. Tests were carried out to confirm that the camera did not affect the functionality of the system or alter the flow in any way. The results of the tests on BCSA soil-cement were compared with untreated soil and portland soil-cement. In addition, two different soils were used during the tests, one with a higher sand content than the other to determine the effects of BCSA in weaker samples against erosion. Multiple factors and mixture combinations were varied (e.g., cement content, curing time, and moisture content) to evaluate the effects. The results indicated that BCSA cement is a viable alternative to portland cement. However, BCSA requires higher water contents for its hydration, making it more susceptible to the adverse effects of clay presence, potentially impacting its erodibility performance more significantly than portland cement.

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