Mohammad Mehdi Khabiri - Academia.edu (original) (raw)

Papers by Mohammad Mehdi Khabiri

Communications - Scientific letters of the University of Zilina

This research was conducted to investigate the current state of transportation, as well as the tr... more This research was conducted to investigate the current state of transportation, as well as the transportation costs of the residents of towns with affordable residential houses, by preparing and presenting a questionnaire to these residents. In this questionnaire, things like housing costs, the amount of travel to the city center, satisfaction with public transportation services and its variety, easy access to public transportation and required places, the amount of use of public transportation and private vehicles were examined and solutions to reduce transportation costs were presented. Although the price of housing in the towns is lower than in the city center; the costs of transporting the residents of these towns are significant. In addition, the state of public transportation and access to needed places is unfavorable, so that about 60 % of the interviewees were dissatisfied with public transportation services.

Journal of Science and Technology

Mathematical optimization, also called mathematical programming, is the process by which the best... more Mathematical optimization, also called mathematical programming, is the process by which the best answer (according to a set of criteria) is selected from a set of possible answers to a particular problem. Today, optimization problems are used in all quantitative fields such as computer science, engineering, operations research, economics, and more; one of the engineering disciplines in which optimization is very important is road and transportation engineering. Road repair is one of the most important componentsof pavement management that requires regular road inspection by road specialists. One of the most important measures to prevent failure is maintenance inspection; Assessment of the condition of road surfaces to ensure their performance, while the road still provides maximum safety for existing traffic, should be done to ensure timely and effective repair and reconstruction operations. But exactly when these inspections should take place and when they are effective is an issu...

International Journal of Sustainable Construction Engineering and Technology

The existing quicksands in the desert are among the problematic soils whose stabilization has bee... more The existing quicksands in the desert are among the problematic soils whose stabilization has been considered by experts. Emulsion bitumen is one of the environmentally friendly stabilizers of these sands. Also, the method of reinforcement with (fibers) has many advantages due to the increase in soilstrength in the same way and the formation of thickness in the soil mass. The aim of this study was to investigate the effect of polypropylene fibers and emulsion bitumen on improving sandy soil properties and the effect of freeze-thaw cycles on the behavior of soils stabilized by these two substances; For this purpose, samples of aeolian sand soil with 0%, 0.25%, 0.5%, 0.75% and 1% waste polypropylene fibers of 0, 5, 10, 15% bitumen emulsion were made and tested for California load-bearing capacity and uniaxial compressive strength. Also, to evaluate the effect of freeze-thaw cycle, the samples were subjected to uniaxial resistance test after enduring 3 and 7 freeze-thaw cycle. The resu...

Scientific Journal of Silesian University of Technology. Series Transport

Today, the increasing development of urbanization and climate change and its resulting issues, in... more Today, the increasing development of urbanization and climate change and its resulting issues, including the occurrence of urban floods, is one of the important issues facing city managers. One of these problems that seriously affect lives today is the occurrence of floods and the inundation of urban thoroughfares. Among the problems of floods in urban areas are the disruption of the urban transportation system, reduced transportation safety, inundation of thoroughfares, and consequently, the poor appearance of urban roads. One of the successful strategies in controlling urban runoff is the use of porous pavements in urban thoroughfares. The two capabilities of permeability and evaporation of a porous pavement lead to reduced runoff and a resultant lack of occurrence of inundation of thoroughfares; therefore, accurate measurement of these two parameters is of special importance. This study aims to introduce two devices for measuring the permeability and evaporation of porous asphalt...

Stavební obzor - Civil Engineering Journal, 2019

Some roads have a gravel layer and most asphaltic roads have gravel shoulder and part of that san... more Some roads have a gravel layer and most asphaltic roads have gravel shoulder and part of that sand is fine grained soil. Road dust increases in heavy traffic and affects safety, economy, quality and environment. Different stabilizers are used to control the dust in gravel topping roads. One of them is calcium chloride. One of its common uses is the dust control in gravel topping roads. In this research, in order to achieve the optimal mixture procedure after grading the gravel material of pavement surface layer, the effect of calcium chloride salt on the physical properties of the fine grained part was investigated in different percent of calcium chloride samples and different percent of moisture in two dry cases. Results show that increasing the calcium chloride percent in the dry case, the moisture absorption amount of the fine grained part of the gravel topping materials is increased, by contrast, uniaxial tensile and compressive strengths decrease with the increase of calcium ch...

Jordan Journal of Civil Engineering

The effectiveness of weight ratio of mineral filler to effective bitumen in the fatigue performan... more The effectiveness of weight ratio of mineral filler to effective bitumen in the fatigue performance of asphalt mixture with integral granules was investigated based on experiments on bitumen mastic (mixture of bitumen and mineral filler passed through sieve grade 200). The experiments included a dynamic shear rheometer, elastic recovery, linear amplitude sweep tests and other performance tests on asphalt mixture, such as fatigue of indirect tensile and resilient modulus test for assessing the medium temperature with various mineral fillerto- bitumen ratios of: 0.4, 0.6, 0.8, 1.0, 1.2, 1.4 and 1.6 for bitumen 70-16 PG. Based on this project, the weight ratio of mineral filler to effective bitumen according to Iran Management and Planning Organization (IMPO234) and SHRP-A407 standard and based on fatigue performance of asphalt mixture was separated and modified. So, to control and modify the medium temperature, the maximum weight ratio of filler to effective bitumen should be consider...

Frontiers in Built Environment

Today, with the expaansion of cities and the growth of urbanization, followed by climate change, ... more Today, with the expaansion of cities and the growth of urbanization, followed by climate change, it is crucial to prevent the occurrence of floods and control it in cities. Porous pavement, including porous asphalt, is known as one of the best methods for urban flood control due to its two properties of evaporation and permeability. The purpose of this study is to modify the gradation of porous asphalt in order to optimize its permeability and evaporation for low-traffic urban passages. For this purpose, permeability, evaporation, and Cantabro tests were performed on samples with different gradations and percentages of bitumen; then, using Design Expert software, the gradation and percentage of optimal bitumen were determined. Finally, the performance of the asphalt gradation and optimal bitumen percentage were evaluated by performing empty space percentage, modified Latman, Marshall, and psychological strength tests and Cantabro tests. The results show that with finer gradation, th...

Proceedings of the Institution of Civil Engineers - Waste and Resource Management

Disposing of cigarette butts in the environment is considered one of the environmental problems c... more Disposing of cigarette butts in the environment is considered one of the environmental problems caused by smoking, including cigarettes, which leads to soil pollution and adverse effects on the growth of plants, animals, and birds. This study has evaluated the use of cigarette filters as an additive in asphalt. To use the cigarette filter in asphalt, the surface of the filters was first well covered with bitumen to prevent the spread of contaminants in the filter and also the adsorption of bitumen by the filter, and then asphalt samples were prepared with different percentages of cigarette filter (10, 15 and 25 kg/m3). In this study, tests of moisture sensitivity, resilient modulus, heat capacity, ageing and lateral deformation were conducted to evaluate the performance of samples made with different percentages of cigarette filters. According to the results, as the percentage of cigarette filters increases, the resilient modulus and the rate of temperature absorption decrease, and ...

Journal of Applied Research of Chemical -Polymer Engineering, Dec 10, 2020

Solid waste materials can be left out of environment in different ways or can be used again. As a... more Solid waste materials can be left out of environment in different ways or can be used again. As an example of waste fiber materials is the fibers reselling from producing carpet which are made in Iran in largest quantity. These materials are added to soil and granular materials and ...

International Journal of Integrated Engineering, 2016

Performance failures in asphalt pavements, which are related to the use of traditional asphalt ma... more Performance failures in asphalt pavements, which are related to the use of traditional asphalt materials has made pavement scientists to adopt new strategies in utilizing new materials in pavement industry. Some of additive materials are like fiber or yarn including natural and synthetic fiber such as glass and carbon fiber. These materials reinforce the mix and cause increase in tensile strength. In this study, two yarn types were chosen to investigate on; namely, glass and carbon. The aim of this study was to investigate the properties of reinforced asphalt mixtures with carbon and glass fibers. To evaluate the effect of carbon and glass fibers on asphalt mixtures physical performance, Marshal Stability and indirect tensile tests were carried out according to international standards on the samples with and without fibers through the dry method. The results of study showed that fiber glass had greater effect on increasing rutting resistance and increase the percentage of glass fibe...

International Journal of Integrated Engineering, 2015

The slope and width of the road shoulder are important parameters in geometry of the road pavemen... more The slope and width of the road shoulder are important parameters in geometry of the road pavement. Therefore, it is important to comply with the requirements relating to the slope and width of the shoulders. So that by using the minimum width and slope of the shoulders according to regulations not only stresses and strains transferred to the lower layers will decrease, but also reduces damages in asphalt layers, base, and sub-base. Therefore, it is vital to conduct analyses which can bring good amount of accuracy in assessment of the stress and settlement due to shoulder width and slope. The aim of this study is to investigate the effect of geometry of the shoulder on the performance and behavior of weak or strong pavement. For this purpose, numerical two- dimensional modeling of the road pavement (asphalt base sub-base) on which the axel load is placed was done using finite element method, ABAQUS, and the effect of the shoulder width and slope on the stresses and settlements cause...

Reactions created in road construction and secondary distresses made in pavement are dependent on... more Reactions created in road construction and secondary distresses made in pavement are dependent on dimensions and geometry of cracks, resistance of subgrade and existing pavement layers. Thus, this essay assessed the effect of changes in crack’s geometry and also the amount of subgrade resistance on settlement in the cracking place. Since pavement layers thickness has a drastic effect on the resistance of the layers, cracks propagation and secondary distresses, in this essay, different types of strong, semi-strong, and weak pavements have been considered according to combination of different thicknesses for the pavement layers which are respectively wearing layer with the thickness of 5, 10, 20 centimeters, base course with thickness of 10, 20, 40 centimeters and sub base with thickness of 15, 30 and 60 centimeter. Also, as pavement can be constructed in grounds with different resistance and so subgrade resistance has an important role in pavement settlement and distresses, in this ...

Scientific Journal of Silesian University of Technology. Series Transport, 2021

Skip resistance of asphalt is an important parameter that can influence the safety of drivers on ... more Skip resistance of asphalt is an important parameter that can influence the safety of drivers on roads. Although there is a linear relationship between slipping on road surfaces and accidents, the impacts of pollutants for decreasing friction of roads is clear to researchers. Moisture and temperature influence friction and safety. In this research in SMA samples, three different gradations with the maximum nominal sizes of 19, 12.5 and 9.5, based on international standards were used. For polluting the surface, five materials that are found on roads were used, including fine-grained soil, sand, oil, soot and rubber powder. To measure the skip resistance, the British pendulum tester was used and for analysing macro-texture, the sand patch method was used. The results of this research showed that by increasing the maximum nominal size of aggregates, the depth of macro-texture in surfaces are grown and this is due to the decrease of fine aggregates in larger gradations. Because of the h...

Health in Emergencies & Disasters Quarterly, 2020

Background: The rescue operation is dangerous during floods when the street surface is wet and th... more Background: The rescue operation is dangerous during floods when the street surface is wet and the rescue vehicles moving fast. Rural roads are known with a high percentage of run-off-the-road crashes and accidents, mostly affected by the unsuitable and inappropriate speed of the car and failure to keep a safe side distance from the highway alignment. Determining the length of the vertical curve and the stopping distance depends on the speed parameter in the geometric design. This parameter depends on the traffic flow and the vehicle driver. Materials and Methods: The calculation of distance visibility, especially in the vertical and horizontal curves, has a significant role in the geometric design of roads and the safety of roads and drivers. This study investigates changes in two critical parameters of friction surface of pavement and vehicles’ speed on the probability of accidents. In the present study, by changing the speed parameter, namely, increasing speed and decreasing fric...

Communications - Scientific letters of the University of Zilina, 2021

Despite the very important role of primary arteries and transportation network in providing relie... more Despite the very important role of primary arteries and transportation network in providing relief for regions affected by an earthquake and black spots, they have received less attention. Therefore, in the current study, at first, the status quo of the traffic black spots and safe regions was identified to predict the movement direction, evacuation of residents from their habitat and temporary residence using the region zoning. The trips were assigned to the network based on the trip distribution matrix and their relevant travel times both related to the crisis state. The results indicated that out of 94 traffic regions, located in the area under investigation, 7 regions were put in the very low risk or safe regions group and 10 traffic regions were put in a very high-risk group. Additionally, the results indicated that out of 794 links, located in the area under investigation, about 32 links will have a very undesirable status following an earthquake.

Scientific Journal of Silesian University of Technology. Series Transport, 2020

Sidewalks play a very important role in the dynamism maintenance as well as the development of ci... more Sidewalks play a very important role in the dynamism maintenance as well as the development of cities especially historic cities. To ensure the maintaining service quality of sidewalks, the first step is to prevent distress occurrence, thereafter repair the distress that occurred in the sidewalks. In historic cities, the lack of suitable sidewalks for walking led to the gradual elimination of pedestrians. Yazd is a historic city recorded as a world heritage site by UNESCO, which attracts many tourists from all over the world every year. Therefore, preserving the quality of sidewalks in this city is of great importance. In this research, the SCI method was used to investigate the condition of the sidewalks in the studied area. This method is similar to the pavement condition index (PCI) method. The results showed that the condition of sidewalks in the studied area is in the range of 55-70, which is relative.

Journal of Applied Polymer Science, 2017

Presence of filler in an elastomeric composite can affect curing characteristics due to possible ... more Presence of filler in an elastomeric composite can affect curing characteristics due to possible interaction with curing agents. Alteration of the curing characteristics can change intrinsic properties of elastomer including its bulk density and swelling behavior. In this study, a series of acrylonitrile butadiene rubber (NBR) with various curing levels was prepared. From the experimental data the bulk density and network molecular weight (M c,sw) were specified and a relationship was established between these parameters. In order to determine the swelling characteristics of NBR in presence of filler, another series of NBR/silica nanocomposites was prepared with various nanosilica loadings under a constant content of curing agents and curing conditions. With the use of the swelling data and applying the obtained relationship, the M c,sw and bulk density of the filled NBR matrix were resolved. The M c,sw values obtained by considering the influence of nanosilica on curing characteristics of NBR were compared with those obtained simply based on bulk density of raw rubber. This comparison confirmed that there are considerable differences between these values. With increasing nanosilica contents, and hence, increasing the negative impact of the filler on reducing curing degree of NBR, the bulk density of filled NBR matrix was decreased.