Engineering Commons^™

Use Of Wicking Geotextile To Dehydrate Road Embankments, Chuang Lin

Doctoral Dissertations

“Excess water within a pavement structure is the major cause of pavement deteriorations. A roadway is often constructed with soils compacted at the optimum water contents to achieve the best performance. After construction, the soil water content variation is controlled by the ambient environment. The base course aggregate is very sensitive to water content variations. Unfortunately, conventional drainage system can only drain gravity water, but not capillary water, and it cannot work under unsaturated conditions. Consequently, no matter how well the road is constructed, the water content is expected to increase with time and the excess water will inevitably accelerate …

Design And Performance Of Fiber-Reinforced Concrete With Adapted Rheology For Construction And Repair Of Bridge Structures, Ahmed Abdelrazik

Doctoral Dissertations

“The objective of this document is to design high-performance fiber-reinforced self-consolidating concrete (FR-SCC) for infrastructure repair and fiber-reinforced super-workable concrete (FR-SWC) for bridge construction. The investigated fibers included propylene synthetic fibers, hooked steel fibers, double and triple hooked steel fibers, hybrid crimped steel fiber and polypropylene multifilament fibers, and micro-macro steel fibers. The fiber volume varied between 0 and 0.75%. An expansive agent (EA) was incorporated to compensate for shrinkage and induce compression in the concrete at early age. Two types of EA (G and K) were employed at 0 to 8%, by mass of binder. The investigated FRSCC and …

Feasibility And Assessment Of Using Recycled Rubber For Infrastructure Applications, Ahmed A. Gheni

Doctoral Dissertations

“The United States needs to mine billions of tons of raw natural aggregate each year. At the same time, millions of scrap tires are stockpiled every year. Therefore, replacing natural aggregate with recycled crumb rubber aggregate will be beneficial to the construction industry and environment. This research aimed to investigate the feasibility of using recycled rubber in new construction applications. Based on size, recycled rubber was selected to match its natural counterpart. Different ratios of recycled crumb rubber were used as a fine aggregate replacement in concrete masonry units (CMUs) where the rubberized units showed a lower unit weight, higher …

Designing Bifunctional Materials For In-Situ Capture And Conversion Of Volatile Organic Compounds, Anirudh Krishnamurthy

Doctoral Dissertations

”Volatile organic compounds (VOCs) are a class of organic liquid compounds with low vapor pressures, which enables them to vaporize at ambient conditions. VOCs are largely toxic, carcinogenic, and mutagenic, and have profound adverse effects on human health and the ecological environment. Many VOCs cause ruinous health effects even at very low concentrations (ppm) and therefore control of these organic compounds is essential for ensuring good air quality. A large portion of VOCs cause catastrophic health effects such as cancer or liver damage even at very low concentrations (ppm), and the control of these compounds is vital in ensuring good …

The Mechanics Of Precision Presplitting, Anthony Joseph Konya

Doctoral Dissertations

"Precision Presplitting is a widely used method of presplit blasting for the mining and construction industries. In recent years considerable effort has gone into the development of empirical equations based on field data to be able to better design the Precision Presplit for various rock types and structural environments. However, the most widely discussed theory about the mechanics of the presplit formation, that of shockwave collisions, does not appear to be applicable for this method of presplitting.

This research has disproven this theory based on insufficient magnitude of the shockwave from modeling with basic wave mechanics. Other authors have suggested …

Thermomechanical Analysis Of Rock Asperity In Fractures Of Enhanced Geothermal Systems, Chao Zeng

Doctoral Dissertations

"Enhanced Geothermal Systems (EGS) offer great potential for dramatically expanding the use of geothermal energy and become a promising supplement for fossil energy. The EGS is to extract heat by creating a subsurface system to which cold water can be added through injection wells. Injected water is heated by contact with rock and returns to the surface through production well. Fracture provides the primary conduit for fluid flow and heat transfer in natural rock. Fracture is propped by fracture roughness with varying heights which is called asperity. The stability of asperity determines fracture aperture and hence imposes substantial effect on …

Long Period Fiber Grating, Thin Coating Of Graphene And Silver Nanowires, And Corrosion Sensing For Life-Cycle Assessment Of Steel Structures, Chuanrui Guo

Doctoral Dissertations

"This study aims to develop and validate a compact, integrated lab-on-sensor system for simultaneous measurement of strain, temperature and corrosion-induced mass loss in steel structures and concrete reinforcement elements in order to assess their life-cycle performance. The sensing system operates based on the principle of long period fiber gratings (LPFG) that are responsive to both thermal and mechanical deformation, and the change in refractive index of any medium surrounding the optical fiber. To fabricate a LPFG sensor for strain and temperature measurement, a CO₂ laser aided fiber grating system was assembled. To enable mass loss measurement, a low pressure …

Detection And Elimination Of Rock Face Vegetation From Terrestrial Lidar Data Using The Virtual Articulating Conical Probe Algorithm, Kenneth John Boyko

Doctoral Dissertations

"A common use of terrestrial lidar is to conduct studies involving change detection of natural or engineered surfaces. Change detection involves many technical steps beyond the initial data acquisition: data structuring, registration, and elimination of data artifacts such as parallax errors, near-field obstructions, and vegetation. Of these, vegetation detection and elimination with terrestrial lidar scanning (TLS) presents a completely different set of issues when compared to vegetation elimination from aerial lidar scanning (ALS). With ALS, the ground footprint of the lidar laser beam is very large, and the data acquisition hardware supports multi-return waveforms. Also, the underlying surface topography is …

Chemically-Bonded Enamel-Coated Steel Pipelines For Corrosion Protection And Flow Efficiency, Liang Fan

Doctoral Dissertations

"This study is to explore and develop chemically-bonded enamel coating (200-300 um) on steel pipes, when subjected to soil and thermal environments, in order to improve the corrosion protection and safety of hazardous liquid and natural gas pipelines while reducing pressure loss. Out of five types of enamels and their various mixtures, Tomatec slurry and GP2118 powder were selected for steel pipeline applications. They were applied at approximately 810 °C to the inside surface of steel pipes in wet and electrostatic processes, respectively. The thickness and surface roughness of the enamel coating were measured using a gauge and an optical …

Development Of Lidar Assisted Terrestrial Radar Interferometry For Rock Deformation Monitoring, Ricardo Javier Romero Ramirez

Doctoral Dissertations

"Rock and soil slope movements cost millions of dollars annually. During the past few decades, engineers have relied on traditional methods to detect slope movements. These tools are valuable for small spatial areas but, may not be adequate or cost effective for large spatial areas. Remote sensing methods such as terrestrial laser scanning (TLS) and terrestrial radar interferometry (TRI) provide excellent spatial coverage, and with adequate post-data-processing software, sub-millimetric scale deformation sensitivity can be achieved.

This work will present a comparative experimental study between TLS and TRI. The comparative experimental study will allow us to achieve the two main objectives …

Dynamic Impact Induced By Tornadoes Through Simulations Based On Two-Way Wind-Structure Interactions, Tiantian Li

Doctoral Dissertations

"Tornadoes have become a significant cause of property damage, injuries and life losses. Investigations of tornadoes indicate that most fatalities were caused by building failure. For example, in the Joplin, MO tornado of 22 May 2011, 161 people were killed, and 84% fatalities were related to building failure. Therefore, it is imperative to develop science-based tornado-resistant building codes, in order to provide a better level of occupant protection from tornadoes and to minimize the tornado-induced damage. This requires in-depth understanding of the wind characteristics of tornadoes and their wind effects on civil structures, based on which design tornadic wind loading …