MS, University of Cincinnati, 2020, Engineering and Applied Science: Civil Engineering

Roadway shoulders are critical components of pavement structure as they provide lateral support for the entire pavement structure, an increased width to accommodate oversize trucks and equipment, and an emergency area when a vehicle's wheels leave the pavement. Erosion is one of the main issues encountered in unpaved shoulders and that significantly affect roadway driver safety. Roadway shoulders of unbound granular material can be more susceptible to traffic and environmental conditions. This research intends to investigate the factors that affect the performance of unpaved shoulders and the current construction practices to provide an innovative approach that can be used to improve the performance. The laboratory testing program was conducted to assess the rutting and erosion resistance of different types of materials, including base course material and incorporating recycled asphalt pavement (RAP). To validate the results of the laboratory study, a variety of test sections were constructed at different locations using the best performing materials from the laboratory testing program. In addition, field evaluation of the test sections was regularly performed to validate the results of the lab study. Also, rutting analysis and cost analysis were conducted to evaluate the efficiency and the economic impacts of the suggested different alternatives of the test sections.

Committee: Munir Nazzal Ph.D. (Committee Chair); Sara Khoshnevisan Ph.D. (Committee Member); Jiaqi Ma Ph.D. (Committee Member) Subjects: Civil Engineering

MS, Kent State University, 2008, College of Arts and Sciences / Department of Earth Sciences

Engineering properties of a rock considered suitable for rock toe benches in highway embankments are different than the properties required for fill material. A method of evaluating toe-bench material is needed to assess various rock strata that are encountered during preliminary site investigations for highways so that easy distinctions can be made between rock preferred for toe benches, rock favored for use as fill material, and rock that is not suitable for either. Rock quality is assessed on the basis of absorption, density, slake durability, unconfined compressive strength, freeze-thaw durability, and L.A. abrasion loss. These are considered important properties in defining the integrity of the rock, and provide for a basis for systematic evaluation of rock material. A rating classification for evaluating rock material from Carboniferous strata of western Pennsylvania for use as toe-bench material is presented herein. A series of laboratory tests were performed on three sandstone and two limestone rock units for differentiation on the basis of strength, durability, and overall usefulness as a fill material. Samples were collected from five Mississippian-Pennsylvanian strata consisting of low to high durability rock. Typically, low durability rock units such as shales, claystones, and siltstones, etc., are neglected considering their infrequent use as durable rock fill. Specifications for acceptance of rock toe material do not currently exist within state and federal construction manuals. Therefore, research was conducted to determine the commonly specified engineering property values for rock fill applications in highway construction. These engineering properties were then used to determine rational cutoff boundary values for acceptance of rock material for use within a rock toe structure. Values for various properties tested range from 0.26-4.7% for absorption, 2.46-2.67 for specific gravity, 154-170 pounds per cubic foot (pcf) (2.47-2.72 Mg/m3) for bulk dens (open full item for complete abstract)

Committee: Abdul Shakoor PhD (Advisor); Peter Dahl PhD (Committee Member); Ernest Carlson PhD (Committee Member) Subjects: Civil Engineering; Engineering; Geology