Civil Engineeringhttps://aurora.auburn.edu/handle/11200/442562026-04-26T23:33:58Z2026-04-26T23:33:58ZResistance model for confined circular reinforced concrete columns under eccentric loadshttps://aurora.auburn.edu/handle/11200/506652025-01-22T14:31:04ZResistance model for confined circular reinforced concrete columns under eccentric loads
Circular reinforced concrete columns with spiral reinforcement exhibit an increased ductility
and resistance due to the confinement effect. Many experimental investigations and theoretical studies related
to this topic are focused on columns under axial load, while those for eccentric load are seldom. The scope of
the paper is to present a developed calculation model of resistance for eccentrically loaded confined circular
concrete columns. The model assumptions extend procedures of the ACI and Eurocode to the confined
concrete case. In order to determine the resistance of columns in the form of the force-moment interaction
diagrams, a special procedure is elaborated and described in detail. The peak stress and corresponding strain
for axially loaded confined concrete is calculated using the Richart’s model. Then, an increase of ultimate
strength capacity due to confinement is related to the axial strain level. The more the eccentricity, the less
the confinement effect is engaged in the column resistance. The contribution of spiral reinforcement in the
bearing capacity is the greatest in concentrically loaded columns and it vanishes at the point where axial
strain in the concrete column is equal to zero, which initially governed the beneficial effect of the spiral
reinforcement. A sample interaction diagram is obtained for the selected design case and compared with the
diagram for unconfined column.
Data for: Comparison of two dielectric sensors in coarse-grained soils of increasing salinityhttps://aurora.auburn.edu/handle/11200/505392023-07-13T08:30:18ZData for: Comparison of two dielectric sensors in coarse-grained soils of increasing salinity
Moisture content can impact the resilient modulus of pavement base course and subgrade layers. Given its influence on the post-inundation resilient moduli of the coastal pavement and base course and subgrade layers, it is important for transportation management personnel to understand the post-inundation moisture state for short-term and long-term planning. Dielectric soil moisture sensors can be used to obtain real-time soil moisture data; however, in coastal areas these sensors will be exposed to salinity. In this study, the performance of two commercially available dielectric soil moisture sensors, one using Time Domain Reflectometry (TDR) technology and one using capacitance technology, in a laboratory environment with three different soil materials was examined. Both sensors measure volumetric water content (θ), bulk electrical conductivity (σb) and temperature. Volumetric water content values from the sensors were compared to gravimetrically obtained values. The results show that the capacitance sensor was more reliable and more accurately measured volumetric water content in all three soil materials.
UNSATURATED-ZONE WATERhttps://aurora.auburn.edu/handle/11200/503852022-10-12T08:30:22ZUNSATURATED-ZONE WATER
Formation, Fate, and Impacts of Microscopic and Macroscopic Oil-Sediment Residues in Nearshore Marine Environments: A Critical Reviewhttps://aurora.auburn.edu/handle/11200/503842022-10-12T08:30:19ZFormation, Fate, and Impacts of Microscopic and Macroscopic Oil-Sediment Residues in Nearshore Marine Environments: A Critical Review
Crude oil that is spilled in marine environments often interacts with suspended sediments to form residues that can impact the recovery of the affected nearshore ecosystems. When spilled oil and sediment interact, they can form either small microscopic aggregates, commonly referred to as oil-particle aggregates, or large macroscopic agglomerates, referred to as sediment-oil agglomerates or sediment-oil mats. Although these different sized oil-sediment residues have similar compositions, they are formed under different conditions and have different fates in nearshore environments; the goal of this review is to synthesize our current understanding of these two types of residues. We believe that researchers who focus solely on studying either microscopic aggregates or macroscopic agglomerates could benefit from understanding the research findings available in the other field. In this study, we compare and contrast various processes that control the formation, fate, and impacts of these two types of residues in nearshore environments and point out some of the knowledge gaps in this field. Additionally, these residues have been referred to by many names in the past, leading to confusion and misconceptions at times. In this effort, we recommend a uniform nomenclature to distinguish them based on their physical size. Our overall aim is to bridge the gap between microscopic and macroscopic oil-sediment residue literature to foster a robust exchange of ideas, which we believe can lead to the development of efficient strategies for managing oil spills that affect nearshore environments.