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Tehrān, Iran

Hajikarimi P.,Amirkabir University of Technology | Rahi M.,Pasargad Oil Company | Moghadas Nejad F.,Amirkabir University of Technology
Road Materials and Pavement Design | Year: 2015

In this research, three different methods of rutting resistance evaluation of asphalt binders were compared using high temperature characteristics of rubber-modified binders. For this purpose, implementing dynamic shear rheometer, frequency sweep test and repeated creep and recovery test were conducted on neat and modified samples at 60°C. Rutting resistance of asphalt binders were determined by three approaches: the Superpave specification parameter, G*/sin δ, the cross model for calculating zero shear viscosity, and the Burgers model to determine viscous component of creep stiffness. Utilising these three approaches, rutting resistance of modified asphalt binders were determined and then normalised to rutting resistance of the neat asphalt binder in order to calculate rutting resistance improvement ratio. Results showed that ranking of modified asphalt binders according to three approaches is the same while the quantity of improvement was significantly different. Also, based on these methods, it was observed that crumb rubber has better anti-rutting properties than reclaimed rubber. © 2015 Taylor & Francis Source


Darbandi M.,Sharif University of Technology | Abrar B.,Sharif University of Technology | Yazdi M.K.,University of Tehran | Zeinali M.,Pasargad Oil Company | Schneider G.E.,University of Waterloo
American Society of Mechanical Engineers, Fluids Engineering Division (Publication) FEDSM | Year: 2014

In this paper, we investigate the CO emission from an oil refinery gas incinerator both theoretically and experimentally. At the beginning of this research, our collected data from this incinerator showed that the CO contamination would be far exceeding the permissible environmental standards at the stack exhaust. Therefore, we decided to perform a combined theoretical-experimental study to find a reasonable solution to reduce the CO pollution suitably. Our theoretical study showed that a reliable solution would be to increase the incinerator operating temperature. However, we needed to collect some data from this incinerator to examine if our achieved analytical solution would work correctly. In data collection procedure, we were faced with one major difficulty due to the limits of automatic system of incinerator control, which did not let us increase the incinerator temperature readily in real work conditions. As a general remedy, our suggestion was to interfere in this automatic control system and to increase its maximum possible limit of temperature. Evidently, this needed a number of considerations, which could not be performed in a short length period. As a short length remedy, we designed a number of manual control procedures, which let us examine different temporary working conditions for the incinerator. Trying different operating condition, we eventually found a suitable one with minimum CO emission from the incinerator. Although this choice resulted in an increase in the incinerator temperature and a remedy to reduce the high CO emission, it was inversely increased the incinerator fuel consumption, which is rather a negative point. Our further data collection indicated that the excess air of primary incinerator was relatively high. Therefore, we designed an automatic system of inlet air damper to adjust the inlet air, which resulted in avoiding high excess air and consequently suitable saving in the fuel consumption. The details are provided in the rest of paper. Copyright © 2014 by ASME. Source


Kazemi Esfeh H.,Islamic Azad University at Mahshahr | Ghanavati B.,Islamic Azad University at Mahshahr | Shojaei Arani R.,Pasargad Oil Company
ICCCE 2010 - 2010 International Conference on Chemistry and Chemical Engineering, Proceedings | Year: 2010

Need to proper roads and highways will increase with increasing automotive industry and development of cities and countries. Among petroleum products used in road construction and asphalt application for soil stability and adhesion between layers of asphalt are bitumen soluble and Bitumen Emulsions. Bitumen Emulsions are subset of water emulsion that in this type of emulsion dispersed phase is lipophilic and continuous phase is hydrophilic, for mixing these two phases used surface activating agents called emulsifier. Bitumen Emulsions are under other similar emulsion laws hence; basically Bitumen Emulsions from Thermodynamic point of view are unstable fluid and disperse. Considering the importance and benefits of using Bitumen Emulsions, this paper tries to show influence of various factors such as emulsion source, type and amount of emulsifier, particles size of emulsion and other properties of the emulsions are determined. © 2010 IEEE. Source


Kebritchi A.,Isfahan University of Technology | Firoozifar H.,Pasargad Oil Company | Shams K.,Isfahan University of Technology | Jalali-Arani A.,Amirkabir University of Technology
Fuel | Year: 2013

The effect of pre-devulcanization and temperature in waste tire pyrolysis are investigated on pyrolysis time, yield and properties of residual Heavy Fraction Pyrolytic Oil (HFPO). A comparative pyrolysis of usual Ground Tire Rubber (GTR) and a commercial devulcanized ground tire rubber, (known as Reclaim Rubber-RR) is performed in a static-bed batch reactor at 400-600 C and the oil is distillated to light and heavy fractions. Chemical composition studies show higher amounts of aromatics in HFPO than light fraction. As a novel approach, a relationship between isotherm at max temperature and pyrolysis temperature is presented in this work. Pyrolysis time for RR is approximately half of GTR at same temperatures due to RR devulcanized nature. The solid yield is larger for GTR than RR and decreases by temperature. The liquid yield for RR is larger than GTR. Pyrolysis time and liquid yields of GTR and RR approach to each other at higher temperatures. Kinematic viscosity and flash point are larger for GTR oils in comparison with RR. FTIR shows by increasing temperature the ratio of alkanes/aromatic (I2952/I1456) decreased for HR and increased for HG. So it can be said that both oil contain similar functional groups at different concentrations depending on temperature. 1H NMR and 13C NMR spectra shows oils are a mixture of aromatics, alkanes, alkenes, alkynes and ethers or alcohols, which exist in different concentrations. Gel Permeation Chromatography (GPC) shows that pyrolysis of GTR produces oil which is heavier and broader in Mw distribution in comparison with pre-devulcanized sample (RR). Elemental analysis shows similar elemental composition of HFPOs. © 2013 Elsevier Ltd. All rights reserved. Source


Moghadas Nejad F.,Amirkabir University of Technology | Gholami M.,Islamic Azad University at Tehran | Naderi K.,Amirkabir University of Technology | Rahi M.,Pasargad Oil Company
Materials and Structures/Materiaux et Constructions | Year: 2015

Rutting in asphalt pavements may reduce service life and endanger the safety of highway users. In this regard, high density polyethylene (HDPE) is one of the plastomers which can be used to modify asphalt binders and to reduce permanent deformation. However storage stability is a major problem for polyethylene-modified asphalt binders. The objective of this research is to measure the rutting potential of bitumen modified with HDPE while addressing the storage stability issue by using HDPE with low molecular weight. Superpave’s rutting criteria (G*/sin δ), Shenoy’s proposed rutting parameter (G*/(1 –(1/(tg sin δ)))), zero shear viscosity, non-recoverable compliance (Jnr) and recovery parameter(R) are used to characterize the complex rutting behavior of HDPE-modified binders. The results of the storage stability test showed that melt flow index has a significant impact on the increase of the solubility of HDPE which may contribute to a better storage stability of HDPE-modified binders. The results from different rutting parameters indicate that the addition of a 7 % HDPE (by weight) to neat binder, increases the complex modulus significantly and decreases the non-recoverable compliance which results in more rutting resistance. © 2014, RILEM. Source

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