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Effects Of Slurry Type On Drilled Shaft Strength, Cesar Quesada Garcia

USF Tampa Graduate Theses and Dissertations

The main objective of this research is to identify how the strength of drilled shafts is affected by the use of various types of drill slurry. When concrete is placed in drilled shafts it flows out radially and a laitance interface forms creating a crease on the backside of the reinforcement cage due to the laitance trapped in concrete flowing around the rebar. This can cause concrete to not fully encapsulate the steel making the shafts prone to corrosion and the strength of the cover concrete is locally reduced. Over the past 9 years 58, 42-inch diameter shafts have been …

The Evaluation Of Hybrid Slurry Resulting From The Introduction Of Additives To Mineral Slurries, Kyle Douglas Yeasting

USF Tampa Graduate Theses and Dissertations

Drilled shaft construction often requires the use of drill slurry to maintain borehole stability during excavation and concreting. While drill slurry may be composed of fluids ranging from air to petroleum, drilled shaft construction typically makes use of water based drilling fluids. Although clean water may be utilized as a drilling fluid, a premixed slurry consisting of water, minerals, and/or polymers is more commonly used. Florida Department of Transportation (FDOT) specifications require the use of mineral slurry for all primary structures. The slurry resists the intrusion of groundwater, slows the outward migration of drilling fluid from the excavation, and aids …

Thermal Integrity Profiling Instrumentation Development, Byron Keith Anderson

USF Tampa Graduate Theses and Dissertations

This thesis has shown that the development of the instrumentation necessary to provide in-situ thermal imaging for the determination of homogeneity of concrete is theoretically sound.

Drilled shafts are large diameter underground cast-in-place columns that necessarily rely on sound integrity to properly withstand imposed loadings. As a by-product of the most common construction techniques, the entire process is often completely blind whereby the excavation and concreting processes are conducted beneath the surface of the water table (or slurry level). This results in an inability to inspect the final product and in many cases allows anomalous inclusions (soil cave-ins, slurry pockets, …