danial moazami

Zeta potential is known as the electrical potential at the shear plane and is one of the important electro-osmotic properties of clay minerals. For many applications, the sign and the magnitude of the zeta potential is necessary to be known. For clay soils, it is usually negative. In present study, zeta potential of kaolinite clay immersed in various electrolytes namely; CaCl2, Al2(SO4)3, H3PO4, Na2Sio3, and Na2Co3 at different electrolyte concentration is investigated. As a result, the pH strongly altered the zeta potential of kaolinite. Also, zeta potential and specific conductivity have ranged from-86 to +204mV and 1450 to 15900µs/cm, respectively, at pH 2 to 9.3. In addition, pure kaolinite yields in an isoelectric point (IEP) at pH ~ 3.15.Although, there was no IEP for particles suspended in CaCl 2 solution, a shift in IEP towards alkaline part observed when kaolinite particles immersed in Al2(SO4)3 as well as H3PO4 solution.

The necessity of incorporating realistic non-uniform measured contact stresses, tire footprint area, as well as other non-linear and viscoelastic behaviour within tire-pavement interaction have been suggested by many researchers in order to obtain more reliable pavement responses. However, modeling 3D contact stresses with distribution and other non-linear properties in common pavement design procedure seems difficult and impractical because of the complexity usually involved in this process. Therefore, layered linear elastic theory and average circular contact pressure have been widely used in most common pavement design procedures. In this paper, a simple but acceptable method for predicting pavement responses, in the existing layered linear elastic program (KENPAVE) was utilised. This modified method is based on incorporating tire imprint instead of load over inflation pressure ratio and utilizing a more realistic representative value rather than tire inflation pressure for unifo...

Decision makers often perform pavements repairs without considering the maintenance priority and without utilizing a systematic procedure. These kinds of arbitrary decisions do not usually guarantee the effectiveness of budget allocation.Rating approach in Analytical Hierarchy Process (AHP) is one of the most effective techniques in decision making process which was used to facilitate the prioritization of alternatives on the basis of important parameters like pavement condition index, traffic volume and road type. In this study, relative weights of criteria, sub-criteria and inconsistency rate in each pairwise comparison matrix were calculated with the help of MATLAB software, coded M-Files as well as Expert Choice software. Finally, with Ideal-Mode synthesizing in Expert Choice software, final weights for all criteria and sub-criteria were obtained. As a case study, a number of streets in district number 6 of Tehran municipality (Iran) were selected and the final rating model was ...

In the conventional pavement design procedure using multilayer elastic theory, tire loading equal to tire inflation pressure and traditional circular contact area are assumed. Therefore, the area of contact is extremely overestimated and the contact stress is significantly underestimated. Rotary Compactor and Wheel Tracker (RCWT) equipment was designed and fabricated with three different functionalities. The RCWT captures the realistic contact areas of pneumatic tires, simulates the field compaction process, and conducts simulative laboratory wheel tracking test. This study was conducted to determine relative damage of realistic tire-pavement contact area with respect to the traditional contact area. Based on the obtained footprint results, 63 percent difference exists between traditional and effective contact areas. Furthermore, it was found that based on the thickness of asphalt layer, vehicle tire was 2.5 to 1.5 times more damaging than full circular contact area. Moreover, reali...

W ith regard to limits in annual budget for maintenance, inevitably, one must choose prioritized projects to optimize the allocated budget in the network. This paper looks into prioritization based upon models including all effects of important factors such as pavement condition index, road type, traffic volume as well as rehabilitation and maintenance cost. Analytical hierarchy process and fuzzy logic modelling was used for prioritization. Finally, in order to prove the efficiency of the models, some streets located in district No. 6 of Tehran municipality were selected and the favourite mathematical models were executed on those streets. It was concluded that fuzzy logic modelling can be used to prioritize pavements maintenance more efficiently and precisely.

Decision makers often decide on maintenance and rehabilitation of pavements without any systematic procedure. These kinds of arbitrary decisions do not usually guarantee the effectiveness of budget allocation and cannot supply the maintenance needs of a network. A Pavement Management System is able to evaluate the existing condition of roads as well as predicting the future state. Therefore, choosing the most appropriate strategy of maintenance (the best choice with suitable time for execution) according to the available resources becomes possible. In this paper, MicroPAVER, which is one of the most comprehensive pavement management software was discussed. Implementation of different budget scenarios provided in this software such as: unlimited budget, annual budget, etc as well as practical methods of maintenance and other unique features help the decision makers to successfully manage the pavements on both network and project level by examining various trade-offs between allocated...

... References 1. YB Acar, RJ Gale, GA Putnam, J. Hamed, and RL Wong, J. Envir. Sci. Health. 6 (1990) 687-714. 2. SC Chien, CY Ou and YG Wang. ... John Wiley and Sons, New Jersey, (2005). 5. RJ Hunter, Zeta potential in colloid science. New York: Academic Press, (1981). ...

The necessity of incorporating realistic non-uniform measured contact stresses, tire footprint area, as well as other non-linear and viscoelastic behaviour within tire-pavement interaction have been suggested by many researchers in order to obtain more reliable pavement ...

Scientific Research and Essays Vol. 6(12), pp. 2447-2456, 18 June, 2011 Available online at http://www.academicjournals.org/SRE ISSN 1992-2248 ©2011 Academic Journals ... The use of analytical hierarchy process in priority ... Danial Moazami1*, Ratnasamy Muniandy2, ...

Abstract: With regard to limits in annual budget for maintenance, inevitably, one must choose prioritized projects to optimize the allocated budget in the network. This paper looks into prioritization based upon models including all effects of important factors such as pavement condition ...

... Zainuddin bin Md Yusoff Department of Civil Engineering, University Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia; e-mail: zmy@eng.upm.edu.my ABSTRACT ... (both direction), Mirzaye Shirazi st. (both direction), Karim Khane Zand st. ...

This paper looks into the fatigue evaluation of modified and unmodified asphalt binders in Stone Mastic Asphalt (SMA) mixtures using a Crack Meander (CM) technique. Specimens images were taken during the repeated load indirect tensile fatigue test (ITFT) and crack initiation, propagation and failure were analyzed using a developed “Measurement and Mapping of Crack Meander” (MMCM) Software. The results of crack analysis on every SMA specimens were compared with tensile strain plots obtained from the ITFT test. It was concluded that, in addition to strain or dynamic modulus plots, fatigue behavior can be determined using crack appearance as an alternative method.