Engineering Commons^™

A Threshold To Utilize Guayule Resin As A New Binder In Flexible Pavement Industry, Ahmed Hemida, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study denotes a threshold to utilize Guayule Resin as a new bio-based binder or asphalt cement (AC) proportion, both with/out crumb rubber modifier (CRM), regarding solutions for environment, cost, and sustainability aspects. Via this research, 15 designated binders will be presented, all of them were tested as unaged and RTFO, whereas eight binders proceeded with PAV. Superpave was utilized to study their physical properties. Viscosity was examined upon some guayule-based binders with/out CRM, getting 114cP (at 135℃) for BGR, increased to about 3 times with 10%CRM (by weight of liquid binder) and about 7-8 times with 20%CRM. Comparisons among …

Column-Footing Connection Evaluation Of Hollow-Core Composite Bridge Columns, Mohanad M. Abdulazeez, Mohamed Elgawady

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper presents the seismic behavior of two large-scale hollow-core fiber-reinforced polymer-concrete-steel (HC-FCS) precast columns having two different footing connections. The precast HC-FCS column consists of a concrete shell sandwiched between an outer fiber-reinforced polymer (FRP) tube and an inner steel tube. The steel tube was embedded 635 mm (25 inches) into a reinforced concrete footing, while the outer FRP tube confined the concrete shell only i.e. it was truncated at the top surface of the footing. One connection included embedding the steel tube into the footing. The other one included using a corrugated steel pipe (CSP) embedded into the …

Feasibility Of Distributed Fiber Optic Sensor For Corrosion Monitoring Of Steel Bars In Reinforced Concrete, Liang Fan, Yi Bao, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study investigates the feasibility of distributed fiber optic sensor for corrosion monitoring of steel bars embedded in concrete. Two sensor installation methods are compared: (1) attaching the sensor along the bar and (2) winding the sensor on the bar. For the second method, optical fibers were winded spirally on steel bars with different spacings: 0 mm, 2 mm, 5 mm, and 10 mm. Steel bar pull-out testing was conducted to evaluate the effect of presence of distributed sensor on the bond strength of steel—concrete interface. Electrochemical testing was carried out to assess the influence of the installation methods on …

Sensor-Enhanced Analysis And Behavior Of Steel Beams In Fire, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Traditionally, strain data are difficult, if not impossible, to obtain from steel structures in fire due to their harsh environment and temperature measurements are limited to the locations of thermocouples. This paper presents high-temperature measurements using a Brillouin scattering based (distributed) fiber optic sensor and the application of the measured temperatures and material parameters recommended in building codes into the enhanced thermo-mechanical analysis of simply-supported steel beams subjected to combined thermal and loading effects. The distributed temperature sensor captures detailed, non-uniform temperature distributions that are compared locally with thermocouple measurements by less than 5% at a 95% confidence level. The …

Seismic Performance And Retrofit Evaluation Of Hollow-Core Composite Bridge Columns, Mohanad M. Abdulazeez, Ahmed Gheni, Nicholas Colbert, Mohamed Elgawady

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper presents the seismic behavior of large-scale hollow-core fiber-reinforced polymerconcrete-steel (HC-FCS) bridge column. The HC-FCS column consists of a concrete wall sandwiched between an outer fiber-reinforced polymer (FRP) tube and an inner thin-walled steel tube. The width-to-diameter ratio for the steel tube was 147. The column had an outer diameter of 24 inches and a height-to-diameter ratio of 4.0. The steel tube was embedded into reinforced concrete footing with an embedded length of 1.25 times the steel tube diameter, while the FRP tube only confined the concrete wall thickness and curtail at the top of the footing level. The …

Identification Of Transportation Infrastructure At Risk Due To Sea Level Rise And Subsidence Of Land In Coastal Louisiana, Sanjay Tewari, Wesley Palmer

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The coast of Louisiana is under threat because of sea level rise and land subsidence. Sea water is encroaching deeper inland and as a result Louisiana is losing at an alarming rate. The combined effect of sea level rise and land subsidence is variable spatially. This paper focuses on this combined effect in identifying the transportation infrastructure that is at risk of getting affected by the sea-water inundation of the land.

This paper is an attempt of taking account of land elevation data monitored continuously at various locations along the coast of Louisiana and combining it with local sea level …

A Nonlinear Crack Model For Concrete Structure Based On An Extended Scaled Boundary Finite Element Method, Jian-Bo Li, Xin Gao, Xing-An Fu, Chenglin Wu, Gao Lin

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Fracture mechanics is one of the most important approaches to structural safety analysis. Modeling the fracture process zone (FPZ) is critical to understand the nonlinear cracking behavior of heterogeneous quasi-brittle materials such as concrete. In this work, a nonlinear extended scaled boundary finite element method (X-SBFEM) was developed incorporating the cohesive fracture behavior of concrete. This newly developed model consists of an iterative procedure to accurately model the traction distribution within the FPZ accounting for the cohesive interactions between crack surfaces. Numerical validations were conducted on both of the concrete beam and dam structures with various loading conditions. The results …

Inelastic Response Evaluation Of Precast Composite Columns Under Seismic Loads, Mohanad M. Abdulazeez, Mohamed Elgawady

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper presents a non-linear finite element analysis of large-scale hollow-core fiber-reinforced polymer-concrete-thin walled steel (HC-FCS) precast columns under reversed cyclic loading. The HC-FCS columns provide an economical and efficient alternative to conventional concrete bridge columns. The precast HC-FCS column consists of a concrete shell sandwiched between an outer fiber-reinforced polymer (FRP) tube and an inner thin-walled steel tube. The steel tube diameter-to thickness (D_i/t_s) ratio was 254. The proposed FEA model was developed using LS_DYNA multipurpose software and was verified by experimental results performed in this study. The FE model was used to investigate some …

Flexural Rigidity Evaluation Of Seismic Performance Of Hollow-Core Composite Bridge Columns, Mohanad M. Abdulazeez, Mohamed Elgawady

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper investigates experimentally the seismic behavior of two hollow-core fiber-reinforced polymer-concrete-steel HC-FCS columns under cyclic loading as a cantilever. The typical precast HC-FCS member consists of a concrete wall sandwiched between an outer fiber-reinforced polymer (FRP) tube and an inner steel tube. The FRP tube provides continuous confinement for the concrete wall along the height of the column. Five large-scale HC-FCS columns were investigated during this study to estimate the effective flexural (which is an important factor to define the buckling capacity and deflection of such columns) and the effective structural stiffness of the composite columns. These columns have …

Seismic Performance Of Hollow-Core Hc-Fcs Columns Having Inner Steel Tube With High Diameter To Thickness Ratio, Mohanad M. Abdulazeez, Mohamed Elgawady

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper experimentally investigates the seismic behavior of a large-scale hollow-core fiber-reinforced polymer-concrete-steel HC-FCS column under seismic cyclic loading. The HC-FCS column consisted of a concrete shell sandwiched between an outer fiber-reinforced polymer (FRP) tube and an inner steel tube. The FRP tube provides continuous confinement for the concrete shell along the height of the column while the steel tube provides the required flexural strength. The tested column has an inner steel tube that had a diameter-to-thickness ratio (D_i/t) (of 254. The seismic performance of the precast HC-FCS column was compared to that of HC-FCS column having(D_{i …}

Behavior Of Eb Frp Masonry Bond Under Service Temperature, Zuhair Al-Aljaberi, John J. Myers, K. Chandrashekhara

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The interest in advanced composites in repairing and strengthening infrastructure systems has considerably increased, especially as the application externally bonded (EB) fiber reinforced polymer (FRP) has become more well established. Previous research on bond behavior has focused on impact of durability by considering exposure to harsh environmental conditions and testing the specimens after exposure, rather than testing bond performance during exposure. The influence of directly applying temperature on bond behavior represents an open topic that needs to be investigated in more detail. This study is one of the first studies to investigate the bond behavior when the composite is subjected …