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Civil Engineering

Missouri University of Science and Technology

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Series

Rubber

Publication Year

Articles 1 - 7 of 7

Full-Text Articles in Engineering

Evaluation Of Oxidization Of Crumb Rubber-Modified Asphalt During Short-Term Aging, Amir Ghavibazoo, Magdy Abdelrahman, Mohyeldin Ragab Jan 2015

Evaluation Of Oxidization Of Crumb Rubber-Modified Asphalt During Short-Term Aging, Amir Ghavibazoo, Magdy Abdelrahman, Mohyeldin Ragab

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Asphalt binder is subjected to aging during the construction process and service life of pavement. Aging substantially changes the chemical composition and physical properties of asphalt and leads to premature distresses on pavement. It is speculated that crumb rubber modifier (CRM) reduces the susceptibility of asphalt to aging, but its mechanism is not fully understood. Also, the impact of interaction parameters and exchange of components on the aging behavior of a crumb rubber-modified binder is not fully understood. In this study, the effect of CRM on the short-term aging of asphalt was investigated through an analysis of the distinctions between …


Effect Of Crumb Rubber Dissolution On Low-Temperature Performance And Aging Of Asphalt-Rubber Binder, Amir Ghavibazoo, Magdy Abdelrahman Jan 2014

Effect Of Crumb Rubber Dissolution On Low-Temperature Performance And Aging Of Asphalt-Rubber Binder, Amir Ghavibazoo, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Asphalt binder plays a critical role in defining the low-temperature performance of asphalt pavement, and, therefore, enhancing its mechanical behavior at low service temperatures through modification always has been of great interest. Crumb rubber modification of asphalt is one of the common practices in the industry. However, the effect of a crumb rubber modifier (CRM) on low-temperature performance of the binder is not well understood. A CRM swells by absorbing the aromat-ics and light molecular components of asphalt at low interaction temperatures (i.e., 160°C) and dissolves at higher interaction temperatures (i.e., 190°C, 220°C). Each of those activities affects the performance …


Effects Of Interaction Conditions On Internal Network Structure Of Crumb Rubber-Modified Asphalts, Mohyeldin Ragab, Magdy Abdelrahman Jan 2014

Effects Of Interaction Conditions On Internal Network Structure Of Crumb Rubber-Modified Asphalts, Mohyeldin Ragab, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Investigation of the effect of interaction conditions on the development of the internal network structure of crumb rubber-modified asphalt (CRMA) was carried out. Enhancements in the CRMA physical properties, such as stiffness, expressed in the complex modulus (G*), and elasticity, expressed in the phase angle (δ), as a result of the development of three-dimensional (3-D) entangled network structure were achieved. These results came from controlling the interaction conditions of CRMA synthesis to regulate the crumb rubber-modified (CRM) components that were responsible for the formation of the 3-1) entangled network structure. Dissolution tests and thermogravimetric analysis (TGA) were performed on the …


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 …


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 …


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 …


Controlling Performance Of Crumb Rubber-Modified Binders Through Addition Of Polymer Modifiers, Magdy Abdelrahman Jan 2006

Controlling Performance Of Crumb Rubber-Modified Binders Through Addition Of Polymer Modifiers, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The use of tire rubber as a modifier to enhance the properties of asphalt mixes through the wet process has proved to be a successful procedure, but full control of the properties of crumb rubber-modified binders has been a challenge. The literature indicates a wide variation on adding rubber to asphalt and that the degree of success of rubber modification in AC mixes depends on several factors, the majority of which relate to the method of mixing, storing, and transporting and to construction technologies. Understanding the nature of the interaction process between asphalt cement and crumb rubber-modifier (CRM) helps explain …