فصلنامه جاده
سال بیست و نهم شماره 4 (پیاپی 109، زمستان 1400)

Reclaimed asphalt pavement (RAP) materials, which include aggregate and bitumen, can be used in recycled asphalt mixes and granular base layers. Recycling these materials helps conserve natural aggregates resources. It also reduces energy consumption and costs. However, due to the variety of sources as well as insufficient strength, RAP materials without stabilizing additive is not suitable as an alternative to virgin aggregates in granular base layers. Therefore, it is necessary to use a suitable chemical or mechanical stabilization method to use reclaimed asphalt pavement as a base material. In this paper, the properties of RAP materials and aggregates containing different percentages of RAP are reviewed. Then the results of recent studies on the mechanical properties of these materials are presented. The results of this paper show that with increasing the percentage of RAP (Reclaimed asphalt pavement) material in mixtures containing RAP, the resilient modulus and the accumulated permanent deformation increase.

movable bridge can temporarily stop one type of their performance and get out of their position. These bridges can be used as pedestrian bridges, road or water transportation. In this study, after introducing movable bridges, the types of these mechanisms are examined. The movement of movable bridges is done through six groups of rail, bascule, vertical, swing, tilting and folding mechanisms. The results of the evaluation of 50 samples made in the world show that among these mechanisms, bascule movement is the most common mechanism and rail movements cover the largest opening due to the lightness of the structure. In some mechanisms, such as swing and bascule mechanisms, it is possible to cover larger openings with the help of design in the form of two separate bridges with side supports. More than 90 Percentage of the movable bridges are made of steel and their deck support system is generally designed from trusses or plate girders. Today, with the advancement of technology, many of these bridges become a symbol for countries

Carpooling is a method in which people whose place of residence and work is located in the same area, find each other and arrange to travel in one personal vehicle. This is one of the methods of traffic demand management that is a helpful way for sustainable development. Therefore, it is important to expand the use of this method among the people in society by examining the factors affecting the tendency for carpooling. In this study, an attempt was made to examine different cities in order to have more validity. According to the parameters that could affect the use of carpooling, a number of them were selected and a questionnaire was designed according to the effective factors. In this study, using linear regression method, it was found that the parameters of private car ownership, difference in working hours, access to public transportation and being near to the city center affect the reception rate of carpooling. A linear model was obtained by which the number of carpooled trips can be estimated for different work places..

There are several methods for analyzing flexible pavements, where the most widely used of which are the multilayerd theory and finite element method (FEM). In this study, two sections of four-layered pavement with assuming two temperatures for surface layer (25 and 40 °C) were analysed and five responses at radial distances obtained from nonlinear analysis using two methods of multilayered theory and finite element method were compared. NonPAS program is employed for nonlinear analysis of these two sections based on the multilayered theory and MICHPAVE program is used for nonlinear analysis of these two sections based on the finite element method. Also, 7 different methods have been used to determine stress points and correct stresses in the multilayered theory method. The results of the analysis showed that only for the vertical stress response on the subgrade, the results of the two programs are very different and for other responses, the difference between the two programs is reasonable. It was also found that the responses obtained from the NonPAS program for a thicker section were in better agreement with the results obtained from the MICHPAVE program. Among the 7 methods considered for determining the stress points in the multilayered method, method 7, which is based on sublayering the nonlinear layer and considering the stress points in the central depth of the sublayers and modifying the radial stresses based on the maximum tensile strength of the materials according to Mohre's failure criterion showed best conformity with the results of MICHPAVE program.

The purpose of this study is to investigate the seismic design methods of the retaining walls. Seismic behavior of the retaining walls for dynamic loads, seismic design and stability of these structures during the earthquake were studied by studying retaining wall design methods. The overall lateral pressures during earthquake vibrations are the static pressures that occur before the earthquake and the dynamic pressures generated by the earthquake, and the wall response is affected by both pressures. The results of this study show that if there is a possibility of sliding, rotating, or deforming to a sufficient degree to be able to mobilize the active soil pressure, the dynamic wall pressures will be applied via static or semi-static Mononobe -Okabe methods. In case of impermeability of the retaining walls (fixed walls), elastic analysis is also performed, and the most common dynamic analysis methods include the Mononobe -Okabe semi-static method, the Steedman - Zeng method, the Wood method and the Westergaard method, which can be developed.

Noise pollution in urban transportation systems is one of the hazards that can always endanger the health of passengers and affect their use of public transportation.

Noise pollution was assessed on station platforms, passenger cars as well as train wagons. According to the sound level data of the stations and the collected data, the modeling was done using a regression linear model. Using correlation analysis, the effect of various factors on noise pollution index was investigated.

The equivalent noise level index in a certain period of time Leq in Nawab station is more than the other 3 stations that the initial assumption about the noise pollution rate is higher due to the large number of passengers. Also Sanat Square was the quietest station among the studied stations. The equivalent sound level was picked up at a certain point in Leq at Nawab Station 83 and Sanat Square 77, which is another initial assumption about the recorded environmental pollution and lack of close monitoring.

The permissible noise pollution limit (65 decibels) has been higher in most of the measured points, so that in Maidan Sanat station, which was the quietest station at the time of train arrival and departure, the equivalent sound level of 77 decibels was collected. Has been above the standard.

The recent increase in bitumen prices and environmental considerations has expanded the use of recycled asphalt mixtures. These mixtures are prepared with different percentages of recycled and new materials including bitumen and aggregate. Sometimes it is necessary to examine the effect of different laboratory parameters quickly and with a smaller number of samples. In this paper, the Taguchi method with 3 effective factors including the percentage of recycled materials (in three levels of 0, 25 and 50%), type of recycled materials (in two levels of two different sources) and the percentage of bitumen (in 3 levels of 4, 5 and 6%) was used to design experiments for rapid analysis of laboratory samples. The strength and volumetric characteristics of asphalt mixtures were determined and analyzed using Minitab software in L18 orthogonal array. The effect of each of the input parameters on the obtained results was determined by signal-to-noise ratio and analysis of variance. The results showed that the percentage of recycled materials significantly affects the strength and volumetric behavior of recycled mixtures. Contrary to expectations, the effect of the source of recycled materials is less than other input parameters.

The purpose of this study is to investigate the role of human capital and dynamic marketing capabilities on competitive advantage in in airlines active in the country's aviation industry. this research as an applied research in terms of research purpose and as a descriptive-survey research of correlational type and structural equations based on the method of data collection. The statistical population in this study is 400 managers, deputies and some administrative staff of airlines active in the country's aviation industry. The sample size in this study was 196 using Cochran's formula. The sampling method in this research is cluster sampling. The tool of this research is a questionnaire and for the validity of the research, the prepared questionnaire is provided to the subject experts, including respected professors and advisors, and after applying their opinions and their final approval in terms of appearance of the questionnaire, the final questionnaire was used as a basis. For reliability, Cronbach's alpha coefficient was used and also the total reliability of the questionnaire was "0.806", which indicates the high reliability of the research questionnaire. Data analysis Structural equation analysis and covariance, covariance were calculated to determine the difference and data analysis with structural equations and PLS Smart software. In this study, 7 hypotheses were analyzed and all hypotheses were confirmed.

In this study, the amount of pollution and impact of construction machinery was studied on air pollution in the project of construction of Shiraz Urban Train Station. Air pollution parameters were collected and extracted from the EPA station which is near the project implementation site, including PM10, PM2.5 , So2 , No2 , O3 , CO. Some pieces of information were collected from the Urban Train Organization. the type and number of machines involved in the project and their hours of operation from. the data collected from the Meteorological Office, the weather and the amount of dust were determined . Workshop equipment and fuel consumption were calculated based on daily workshop activities of each machine and amount of contamination was determined based on amount of fuel consumed. As well as analysis, review and percentage of air pollutants caused by construction project activity were specified. In compared to average of the pollutants, each of the pollutants caused by workshop activity with average pollutants measured by measurement station, the percentage of pollution caused by workshop activity is CO=46/56%, O3=46/48%, NO249/53%, SO2=60/68%, PM10=39/22, PM2.5=56/08. There was a direct relationship between the pollutants measured by the measuring station activity level of workshop, with highest activity index in the months when workshop showed highest number of pollutants, and at same time, air pollution monitoring station had higher numbers of pollutants in these months. it shows. Devices that have a higher workshop activity index have higher fuel consumption and a higher share of air pollution.

The high desire of Tehran citizens to use personal vehicles has made traffic one of the main challenges in Tehran. This imposes heavy environmental and economic costs on this city as the capital of the country. Tehran, as the most populous city in Iran, has always faced the problem of increasing urbanization, urban traffic and lack of public parking lots. This problem is exacerbated especially in the central areas of the city, which are politically, economically and socially centralized and increase the need to create public parking lots, especially multi-story car parks that have a higher capacity despite occupying less space. The present study aims to provide a hybrid model under a fuzzy environment for the location of multi-story car parks in District 12 of Tehran with an emphasis on urban sustainable development management to provide a solution to this problem. Therefore, in the first step, 3 criteria and 21 sub-criteria were identified with emphasis on the dimensions of sustainable development. Then, the selected criteria were weighed using the fuzzy SWARA method and the potential parking areas were identified using the fuzzy ARAS method. Finally, using GIS technique, 7 suitable spots in area 3 of district 12 were identified to create multi-story car parks. The one of the most important aspects of this research is the complete classification of urban sustainability dimensions for the selection of multi-story car parks. Also, in this research, a new combination of fuzzy SWARA, fuzzy ARAS and GIS has been used for optimal decision making.

Due to an increase in urbanization, many trips are made in cities for work-related as well as non-work-related purposes. This amount of trips will cause traffic jams, and not only pollutes the air, but also causes wasting of time. Some governments enforce congestion pricing to reduce the consequences of traffic. The main purpose of this study is to investigate the effect of trust in government, environmental concern and time saving value on perception of congestion pricing fair and investigate the moderating role of income and area of residence in the research model. Present study is a descriptive-survey research method, and in terms of purpose, is a developmental-applied research. The population of this research is people who live in Tehran. Available stratified sampling has been used for this research. Data were collected from 234 questionnaires were analyzed by SPSS and SmartPls3 software. The results of the research show that the variables of trust in government and time saving value from the perspective of people living in Tehran affect the perception of congestion pricing fair also, The moderating role of income variables in relation to trust in government and the perception of congestion pricing fair was confirmed. But, the moderating role of the area of residence variable has not been confirmed between the relationship trust in government and the perception of congestion pricing fair and, the results demonstration that the environmental concern variable does not affect perception of congestion pricing fair.

Massive amount of debris and trashes, one of the issues and problems of today's world is the especially asphalts debris resulting from the removal of worn-out pavements of urban roads. Recycled asphalt crumbs are waste materials that certainly have significant undesirable effects on the surrounding environment. Given the properties reported by these materials, there are various ways to reuse these materials. One of the applications that have been considered by researchers is the use of these materials in cement mixtures, including concrete production. This is while that a large amount of asphalt fragment is continuously produced in the repair and maintenance of roads. It is therefore desirable to be used in conventional mixtures used in Construction of roads pavement. In this regard, the present study investigates the performance Evaluation of Roller Compacted Concrete Pavement make by Recycled Asphalt using Micro Silica with the aim of reducing waste and its negative impacts on the environment. By examining the documentation and performing numerous experiments, it has been found that roller compact concrete made from recycled asphalt can be used as a suitable pavement for low traffic and rural roads, as well as for the final covering of a wide range of sidewalks. It is also suitable as CBT.

Satisfaction is an important concept that deserves further interest. From consumer research, satisfaction is known to be of great value in understanding customers’ perceptions and evaluations, repeatedly showing itself to be an important indicator of future customer behavior. Customer satisfaction, therefore, highlights and explains the link between what a company does and how its customers react. For public transport, this link is a key concern. In many countries, major investments are being made in public transport systems in order to make them more competitive with other means of transport, most notably private cars. New services are being developed and old ones are being improved. However, an increase in supply will not automatically lead to a corresponding increase in demand and satisfaction. To make sure that investment really attracts the existing and potential customers expected, knowledge of satisfaction should provide policymakers and operational managers in the public transport system with valuable information. In particular, satisfaction studies can provide decision-makers with information about what customers consider important, as well as information about how the existing public transport service is perceived as performing in these dimensions. In this study, the factors affecting people's satisfaction with public transportation in Tehran are investigated. Behavioral inclination theory has been used for this purpose. The results of the structural equation model payment using 257 collected data show a direct and significant effect of both variables in both metro and high-speed buses.