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Civil Engineering

Missouri University of Science and Technology

Series

2013

Articles 1 - 9 of 9

Full-Text Articles in Engineering

Mechanism Of Crumb Rubber Modifier Dissolution Into Asphalt Matrix And Its Effect On Final Physical Properties Of Crumb Rubber-Modified Binder, Amir Ghavibazoo, Magdy Abdelrahman, Mohyeldin Ragab Dec 2013

Mechanism Of Crumb Rubber Modifier Dissolution Into Asphalt Matrix And Its Effect On Final Physical Properties Of Crumb Rubber-Modified Binder, Amir Ghavibazoo, Magdy Abdelrahman, Mohyeldin Ragab

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Modification of asphalt by crumb rubber modifier (CRM) is mostly done through exchange of components between asphalt and CRM. At 160⁰ C and 10 Hz, CRM absorbs aromatics of asphalt and swells; however, at 220⁰ C and 50 Hz, CRM dissolves into the asphalt; this process leads to the release of different components of CRM including carbon black, fillers, and polymeric and oily components. Depending on interaction conditions, CRM dissolution is performed differently, and therefore the state and role of the released components can be different. In this research different mechanisms of dissolution of one size of CRM in asphalt …

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Dynamics And Dislodgment From Pore Constrictions Of A Trapped Nonwetting Droplet Stimulated By Seismic Waves, Wen Deng, M. Bayani Cardenas Jul 2013

Dynamics And Dislodgment From Pore Constrictions Of A Trapped Nonwetting Droplet Stimulated By Seismic Waves, Wen Deng, M. Bayani Cardenas

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Seismic waves affect fluid flow and transport processes in porous media. Therefore, quantitative understanding of the role of seismic waves in subsurface hydrodynamics is important for the development of practical applications and prediction of natural phenomena. We present a theoretical fluid dynamics model to describe how low-frequency elastic waves mobilize isolated droplets trapped in pores by capillary resistance. The ability of the theoretical model to predict the critical mobilization amplitudes (Ac) and the displacement dynamics of the nonwetting droplet are validated against computational fluid dynamics (CFD) simulations. Our theory has the advantage of rapid calculation of Ac …

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Real Time Bridge Scour Monitoring With Magneto-Inductive Field Coupling, Andriy V. Radchenko, David Pommerenke, Genda Chen, Pratik Maheshwari, Satyajeet R. Shinde, Viswa Pilla, Y. Rosa Zheng Mar 2013

Real Time Bridge Scour Monitoring With Magneto-Inductive Field Coupling, Andriy V. Radchenko, David Pommerenke, Genda Chen, Pratik Maheshwari, Satyajeet R. Shinde, Viswa Pilla, Y. Rosa Zheng

Electrical and Computer Engineering Faculty Research & Creative Works

Scour was responsible for most of the U.S. bridges that collapsed during the past 40 years. The maximum scour depth is the most critical parameter in bridge design and maintenance. Due to scouring and refilling of river-bed deposits, existing technologies face a challenge in measuring the maximum scour depth during a strong flood. In this study, a new methodology is proposed for real time scour monitoring of bridges. Smart Rocks with embedded electronics are deployed around the foundation of a bridge as field agents. With wireless communications, these sensors can send their position change information to a nearby mobile station. …

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Pore Geometry Effects On Intrapore Viscous To Inertial Flows And On Effective Hydraulic Parameters, Kuldeep Chaudhary, M. Bayani Cardenas, Wen Deng, Philip C. Bennett Feb 2013

Pore Geometry Effects On Intrapore Viscous To Inertial Flows And On Effective Hydraulic Parameters, Kuldeep Chaudhary, M. Bayani Cardenas, Wen Deng, Philip C. Bennett

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this article, the effects of different diverging-converging pore geometries were investigated, and the microscale fluid flow and effective hydraulic properties from these pores were compared with that of a pipe from viscous to inertial laminar flow regimes. The flow fields are obtained using computational fluid dynamics, and the comparative analysis is based on a new dimensionless hydraulic shape factor β, which is the "specific surface" scaled by the length of pores. Results from all diverging-converging pores show an inverse pattern in velocity and vorticity distributions relative to the pipe flow. The hydraulic conductivity K of all pores is …

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Cardinal Raúl Silva Henríquez Bridge During The 2010 Chile Earthquake, Zuocai Wang, Genda Chen, W. Phillip Yen, Ian G. Buckle Jan 2013

Cardinal Raúl Silva Henríquez Bridge During The 2010 Chile Earthquake, Zuocai Wang, Genda Chen, W. Phillip Yen, Ian G. Buckle

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper presents a case study of the Cardinal Raúl Silva Henríquez Bridge, which experienced significant damage during an earthquake that occurred in Chile on February 27, 2010. Supported by reinforced concrete and steel columns of varying heights, the superstructure of the bridge consisted of 22 steel-girder spans, with one intermediate expansion joint located at the middle of the bridge. At each end of the bridge, the bottom flanges of the girders were welded to their bearing steel plates, which were embedded and anchored into the bridge abutment. Two, three-dimensional, finite element models (global versus local) with beam and solid …

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Performance Enhancement Of Crumb Rubber-Modified Asphalts Through Control Of The Developed Internal Network Structure, Mohyeldin Ragab, Magdy Abdelrahman, Amir Ghavibzaoo Jan 2013

Performance Enhancement Of Crumb Rubber-Modified Asphalts Through Control Of The Developed Internal Network Structure, Mohyeldin Ragab, Magdy Abdelrahman, Amir Ghavibzaoo

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Control of the internal network structure of crumb rubber-modified asphalt (CRMA) was investigated for its effect on property development in the study presented in this paper. The investigation included evaluation by rheological and interrupted shear tests. Rheological testing involved the monitoring of the changes of the produced complex modulus (G*) and phase angle (δ) for CRMA. In the interrupted shear tests, the shear stress profile for the produced CRMA was investigated. It was found that triggering the critical conditions of the combined interaction of speed, temperature, and time was essential to inducing the formation of the three-dimensional network …

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The Guayule Plant: A Renewable, Domestic Source Of Binder Materials For Flexible Pavement Mixtures, David Newton Richardson, Steven Michael Lusher Jan 2013

The Guayule Plant: A Renewable, Domestic Source Of Binder Materials For Flexible Pavement Mixtures, David Newton Richardson, Steven Michael Lusher

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Due to the rising price of crude oil, flexible pavement costs have increased significantly. This price pressure has resulted in the increased use of reclaimed asphalt pavement (RAP) and/or reclaimed asphalt roofing shingles (RAS) because of the binder (asphalt cement) they contain. This has increased demand for recycling (rejuvenating) agents which return the RAP/RAS binders to their original state by 1) restoring maltenes (petroleum oils and resins) that have been depleted due to age-hardening/oxidation, and 2) reducing their viscosity. The project concept was to design a flexible pavement mixture (FPM) produced with little-to-no virgin petroleumbased binder which implied the use …

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Effect Of Crumb Rubber Modifier Dissolution On Storage Stability Of Crumb Rubber-Modified Asphalt, Amir Ghavibazoo, Magdy Abdelrahman, Mohyeldin Ragab Jan 2013

Effect Of Crumb Rubber Modifier Dissolution On Storage Stability Of Crumb Rubber-Modified Asphalt, Amir Ghavibazoo, Magdy Abdelrahman, Mohyeldin Ragab

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Crumb rubber-modified asphalt (CRMA) extensively suffers from high-temperature storage instability. Because of the higher density of the crumb rubber modifier (CRM) particles, they settle down to the bottom of storage tanks and cause variation between physical properties of the top and bottom samples. The storage stability of the CRMA changes under different interaction parameters and consequently different mechanisms of interaction. In this research the mechanism of separation under different levels of CRM dissolution was investigated by using Stokes' law. The extent and mechanism of CRM dissolution in asphalt was controlled through regulating interaction temperature and interaction mixing speed. A standard …

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Modeling Of The Resilient Modulus For Recycled Asphalt Pavement Applications In Base Course Layers, Ehab Noureldin, Magdy Abdelrahman Jan 2013

Modeling Of The Resilient Modulus For Recycled Asphalt Pavement Applications In Base Course Layers, Ehab Noureldin, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The resilient modulus (MR) is an important parameter for the base course layer in the pavement design process. Use of recycled asphalt pavement (RAP) for this layer must take into consideration the effect of various factors that may occur in the field on the MR. Previous numerical models used for the granular base layer could be used for the RAP. The study reported here examined the suitability of RAP procedures under the effect of different factors (e.g., water content, dry density, freeze-thaw cycles). Various percentages of the RAP (50%, 75%, and 100% by weight) were employed …

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