Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 9 of 9
Full-Text Articles in Engineering
Smart Rocks For Bridge Scour Monitoring -- Design And Localization Using Electromagnetic Techniques And Embedded Orientation Sensors, Andro Radchenko
Smart Rocks For Bridge Scour Monitoring -- Design And Localization Using Electromagnetic Techniques And Embedded Orientation Sensors, Andro Radchenko
Doctoral Dissertations
"River bridge scour is an erosion process in which flowing water removes sediment materials (such as sand, rocks) from a bridge foundation, river beds and banks. As a result, the level of the river bed near a bridge pier is lowering such that the bridge foundation stability can be compromised, and the bridge can collapse. The scour is a dynamic process, which can accelerate rapidly during a flood event. Thus, regular monitoring of the scour progress is necessary to be performed at most river bridges. Present techniques are usually expensive, require large man/hour efforts, and often lack the real-time monitoring …
Remote Sensing And Localization Of Smart Rocks With Orientation-Controlled Magnets For Real-Time Monitoring Of Bridge Scour And Riprap Effectiveness, Yan Tang
Doctoral Dissertations
"This study aims to develop and implement a novel smart rock technology for real-time monitoring of the maximum scour depth and the effectiveness of riprap mitigation measures. A smart rock is one or more stacked magnets encased in concrete that can automatically roll to the deepest point of a scour hole around a bridge pier and provide its location through remote measurement over time. Once integrated into a riprap measure, the smart rock moves together with natural rocks and is thus a potential indicator of the effectiveness of the riprap measure. Therefore, the localization and movement of smart rocks were …
Novel Applications Of Pulse Pre-Pump Brillouin Optical Time Domain Analysis For Behavior Evaluation Of Structures Under Thermal And Mechanical Loading, Yi Bao
Doctoral Dissertations
"This study aims to: (1) develop an analytical model for the strain transfer effect of distributed fiber optic sensors in a uniform or non-uniform stress field; (2) develop a measurement approach to monitor strains in concrete and detect damage (e.g. crack and delamination) in bonded and unbonded concrete overlays; (3) characterize the strain and temperature sensitivities of distributed fiber optic sensors at elevated temperatures; (4) develop a thermal annealing approach to enhance the thermal stability and temperature sensitivity of the distributed sensors; and (5) apply the distributed sensors to assess structural behaviors of concrete and steel structures exposed to fire. …
Design And Performance Of Cost-Effective Ultra-High Performance Concrete For Prefabricated Elements, Weina Meng
Design And Performance Of Cost-Effective Ultra-High Performance Concrete For Prefabricated Elements, Weina Meng
Doctoral Dissertations
"This study presented in this thesis aims to: (1) develop a mixture design methodology for cost-effective ultra-high-performance concrete (UHPC) incorporating high volume of supplementary cementitious materials and conventional concrete and masonry sands; (2) developed UHPC with adapted rheology incorporating lightweight sand, hybrid fibers, and nanomaterials with improved properties; (3) design prefabricated UHPC panels with fiber-reinforced polymers (FRP) for enhanced flexural properties of stay-in-place panels made with optimized UHPC; and (4) explore potential applications of such UHPC elements. The proposed design methodology produced UHPC mixtures with 28-days compressive strengths higher than 125 and 168 MPa under standard water curing and 1-d …
High-Volume Recycled Materials For Sustainable Transportation Infrastructure, Seyedhamed Sadati
High-Volume Recycled Materials For Sustainable Transportation Infrastructure, Seyedhamed Sadati
Doctoral Dissertations
"The objective of this study is to investigate the feasibility of using high performance concrete made with high-volume of recycled materials in transportation infrastructure. The main focus was to develop mixtures for rigid pavement construction. A variety of fine and coarse recycled concrete aggregates (RCA) were investigated. The feasibility of replacing 50% of Portland cement with industrial by-products and supplementary cementitious materials (SCMs) was also evaluated. Experimental program was conducted to quantify the effect of concrete mixture design and RCA characteristics on mechanical properties, drying shrinkage, cracking potential, and durability of concrete. The development of a database and analysis using …
Durability Behavior Of Fiber Reinforced Polymer And Steel Reinforced Polymer For Infrastructure Applications, Wei Wang
Doctoral Dissertations
"Crack development in reinforced concrete (RC) structures is common in elements such as bridge decks. However, these cracks can impose significant problems over time, because they allow chlorides from deicing chemicals to infiltrate concrete which will then corrode steel bars as RC structures are exposed to harsh weather. In the last decade, composite reinforcement systems are internally or externally applied to concrete structures instead of traditional steel reinforcing bars, or to strengthen concrete elements in flexure and shear. However, studies regarding the long-term durability performance of composite reinforcement systems is limited. Therefore, in order to popularize the application of these …
Design And Performance Of Cost-Effective Ultra High Performance Concrete For Bridge Deck Overlays, Mahdi Valipour
Design And Performance Of Cost-Effective Ultra High Performance Concrete For Bridge Deck Overlays, Mahdi Valipour
Doctoral Dissertations
"The main objective of this research is to develop a cost-effective ultra-high performance concrete (UHPC) for bonded bridge deck overlays. The high durability and mechanical properties of such repair material can offer shorter traffic closures and prolong the service life of the pavement. The UHPC was optimized using supplementary cementitious materials (SCMs), proper combinations of sands, and adequate selection of fiber types and contents. Packing density studies included paste, sand, and fiber combinations. The robustness of optimized UHPC mixtures to variations of mixing and curing temperatures was examined. The efficiency of various shrinkage mitigation approaches in reducing autogenous and drying …
Characterization And Performance Of Eco And Crack-Free High-Performance Concrete For Sustainable Infrastructure, Iman Mehdipour
Characterization And Performance Of Eco And Crack-Free High-Performance Concrete For Sustainable Infrastructure, Iman Mehdipour
Doctoral Dissertations
"The main objective of this study is to develop, characterize, and validate the performance of a new class of environmentally friendly, economical, and crack-free high-performance concrete referred to as Eco and crack-free HPC that is proportioned with high content of recycle materials. Two classes of Eco-HPC are designed for: (I) pavement (Eco-Pave-Crete); and (II) bridge infrastructure (Eco-Bridge-Crete). Eco-HPC mixtures were designed to have relatively low binder content up to 350 kg/m3 and develop high resistance to shrinkage and superior durability. A stepwise mixture design methodology was proposed to: (i) optimize binder system and aggregate skeleton to optimize packing density …
Long-Period Fiber Grating Corrosion Sensors For Life-Cycle Monitoring And Assessment Of Reinforced Concrete Structures, Yizheng Chen
Long-Period Fiber Grating Corrosion Sensors For Life-Cycle Monitoring And Assessment Of Reinforced Concrete Structures, Yizheng Chen
Doctoral Dissertations
"This study aims to: (1) explore, develop, calibrate and validate Fe-C coated, long period fiber grating (LPFG) sensors for short-term mass loss measurement of the Fe-C coating; (2) develop, calibrate, and validate steel tube-encapsulated, fiber optic probes and LPFG sensors for long-term mass loss detection of the steel tube; (3) correlate the corrosion process of packaging metal materials with that of steel bars in direct contact with the packaged probe or sensor except for a thin insulation tape; and (4) apply both types of corrosion sensors into reinforced concrete (RC) structures for reinforcing bar corrosion monitoring and structural condition assessment. …