فهرست مطالب حامد خانی سانیج

In developing countries, the crash risk on mountainous rural highways is higher than on non-mountainous rural highways due to their complex geometric design. Thus, the consistency of geometric characteristics with drivers’ behavior plays a remarkable role in reducing crashes in these areas. In this study, two substandard mountainous rural highways of Iran were selected to measure local design consistency based on continuous speed data collected by smartphone technology. The idea of employing critical elements was introduced to evaluate local design consistency. The critical element is an individual element with a higher CCR (curvature change rate) value compared to the CCR values of their adjacent elements. An individual element was defined as a curve or a group of curves with similar CCR values, and short tangents between each two curves. The efficiency of this concept was evaluated base on statistical hypothesis test and determining spearman rank coefficient between a popular design consistency indictor and expected rural highway crashes. The null hypothesis was rejected for all of the critical elements and it was confirmed that drivers reduce their speed when they face the critical element. Finally, several concepts related to design consistency on mountainous rural highways were elaborated according to operating speed profiles.

This research evaluated the effect of epoxy resins on the moisture resistance of asphalt mixtures of each bitumen and aggregate (limestone and siliceous) combination by measuring their surface free energy characteristics. The laboratory method measured the contact angle of several probe liquids called the Sessile Drop method. Bitumen polarity, cohesion energy, adhesion energy, bonding energy, energy parameter related to adhesion performance and energy parameter related to wetting performance of aggregate surface by bitumen for each combination of bitumen and limestone and siliceous aggregates were investigated. The results show that epoxy resins increase the polarity of bitumen, but they do not have a positive effect on increasing the cohesion energy of bitumen. For all the studied bitumen-aggregate compounds containing epoxy resin, the adhesion and wetting performance has increased compared to the compounds containing base bitumen, which indicates the proper performance of this additive in improving the moisture resistance of asphalt mixtures.

Numerous people have died and economically damaged due to the road accidents. One of the efficient ways of reducing crashes is to predict them before happening. This paper investigated the power of artificial-neural network (ANN) model to predict crash frequencies of Naein-Ardakan road, located in Yazd, Iran. To date, there seems no research done to compare the effects of ANN training functions on prediction performance. This research aimed to determine the proper ANN training algorithm for crash frequency prediction. In this regard, four different training algorithms were investigated. The results demonstrated the outperformance of ‘trainlm’ algorithm. Additionally, it was found that the average daily traffic per lane and gap lengths is the most influential factors in crash occurrences, respectively. The present study can be applied to more precisely explain the effects of independent variables on crash outcomes. An in-depth explanation of the effectiveness of independent variables can assist road safety experts in making better decisions for reducing accidents.

One of the environmental problems caused by smoking, including cigarette filter, is the elimination the cigarette filter from the environment that cause soil pollution, and adverse effects on the growth of plants, animals and birds. On the other hand, due to the increasing economic costs and inaccessibility of natural materials, the reuse of nature's wastes in the construction of roads has expanded. Therefore, this study evaluated the use of cigarette filter as an additive in asphalt. Asphalt containing cigarette filter was used to prevent pollution of the filter as well as the bitumen absorption by the filter was first coated with bitumen on the surface of the filter, followed by asphalt samples with different percentages of cigarette filter. (10, 15 and 25 kg / m3) were made.In order to evaluate the performance of asphalt samples, Marshall Stability and indirect tensile tests were performed, and also. Optimum bitumen percentage and optimum filter percentage were obtained using Design Expert software.The results showed that adding 15 kg / m3 of cigarette filter increased marshal stability by 28% and marshal Quotient by 7%. The increase of 25 kg / m3 of cigarette filter to hot asphalt mixture resulted in a 22% decrease in indirect tensile strength. According to the results of the Design Expert software, the optimum filter amount was 15 kg / m3 and the optimum bitumen percentage was 5%.

Overburdens are stones that lack the required properties of minerals to be extracted and are piled adjacent to mine, while they may be used as aggregates in the asphalt mixture. Set-tlement is a cheap mineral composed of iron oxide, silicone and aluminum oxide, application of iron, silica and aluminum as aggregates in pavement industry has great effect on per-formance of asphalt mixtures. In this study, we investigated the effect of using Sillimanite aggregate material as an alter-native for Limestone aggregates on resilient modulus, Mar-shall Strength and skid resistance parameters at various tem-peratures. The modeling was carried out by using finite ele-ment software based on the elastic behavior of the layers to determine the effect of elasticity modulus variations due to the change in aggregate type on the pavement response. The re-sults indicated that the use of Sillimanite aggregates in the asphalt mixture led to a lower optimum bitumen percent than Limestone material; and also, in the asphalt mixture made of Sillimanite aggregates with optimum bitumen percent, Mar-shall Strength was increased by 15% and the resilient modulus by 25% compared to the mixture with Limestone material. Application of Sillimanite material in the asphalt mixture could enhance the friction resistance of the mixture against the abrasion resulting from traffic loading due to its higher hardness compared to Limestone material. The results of nu-merical analysis showed that the aggregate’s type had the lowest effect on the critical tensile strain at the bottom of the asphalt layer, then came the percentage of bitumen in the mix-ture and, finally, the bonding of the layers had the highest ef-fect.

In this paper the effect of Epoxy Resin polymer on moisture sensitivity of Asphalt mixtures containing Silica and limestone aggregates has been evaluated. Epoxy Resin without hardener and Epoxy Resin curing with hardener in 0, 1, 2, 3, 4, and 5 weight percentages for Asphalt Binder modification have been applied. The method used for evaluating moisture sensitivity of Asphalt mixtures is Surface Free Energy method. In this method, with Surface Free Energy measurements of Asphalt Binder using Sessile Drop method and by using of the extracted values of Surface Free Energy of aggregates of valid reports, the energy parameters related to moisture sensitivity of Asphalt mixtures containing Asphalt Binder and aggregates compound, have been calculated and analyzed. At the end, base and modified Asphalt Binders with Epoxy Resin curing with hardener have been examined with FTIR test. The results show that the Epoxy Resin curing with hardener decreases moisture sensitivity of Asphalt mixtures containing Silica and limestone aggregates. Epoxy Resin without hardener does not have important effect on Asphalt mixtures containing limestone aggregates, but decreases moisture sensitivity of Asphalt mixtures containing Silica aggregates.

The present study was a descriptive-analytic research that was conducted on the role of heavy vehicle's sleep quality and sleep quantity in Drowsiness accidents which occurred in the Mehriz-Anar rural highway in Yazd province. In this research, heavy vehicle driver's sleep quality in long distances was considered. The current study data and statistics have been collected through questionnaires completed by heavy vehicle drivers. This information was analyzed by using SPSS-24 software and effective strategies were proposed to improve the driver's sleep quality in order to reduce the incidences and the damages caused by drowsiness. In this study, the linear regression analysis of the sleep quality and the sleep duration was evaluated and the results were presented. The results of this study showed that although many of the authoritie's efforts to oppose driver's fatigue and sleep deprivation in accordance with sleep duration sleep quality has the more effective role in the driver's fatigue and their drowsiness crashes. And now it is considered as the most important factor affecting the safe operation of drivers.

Currently in Iran, the mixing design of stone matrix asphalt mixtures is carried out according to the Marshall method. In Marshall mixing design, the optimum bitumen percentage is determined based on the average amount ​​of the bitumen that leads to the highest Marshall Stability, the highest Specific gravity and the most suitable void percentage in asphalt mixtures with stone matrix asphalt. It doesn’t mean that this bitumen percentage is necessarily the optimum percentage. In this paper, a mathematical model has been developed to determine the optimum bitumen content in stone matrix asphalt by Marshall method, For this purpose, first equations of effective parameters changes in bitumen mix design SMA toward bitumen percent are determined by least squares method and approximating a quadratic polynomial and then relying on these equations and using a multi-purpose mathematical model, optimum bitumen percent is determined in a way that asphalt combination would have all conditions in the code and also would have maximum Marshal stability, the haighest specific gravity and the most appropriate void percentage. After obtaining optimum bitumen content, sensitivity analysis toward very low bitumen percentage on effective parameters (marshall stability, bulk specific gravity of mix asphalt, voids of mix asphalt and voids of aggregate) were done in mix design of stone matrix asphalt. The results of this study indicate that the method of mathematical modeling is more accurate than the traditional method, and sensitivity analysis also showed the effect of error rate on optimum bitumen determination.

One of the technical problems of hot mix asphalt (HMA) in Yazd province is skid resistance. The cause of this problem is the micro-texture (fine texture) of limestone aggregates. The Ghoghart iron mine of Bafgh (Yazd) has million tons of hard and qualified siliceous aggregates which are depot as waste and unusable materials. In this study, the skid resistance and the chemical and physical properties of aggregates have been evaluated. Also, the methods for modifying the moisture sensitivity problem of these types of aggregates have been expressed. The results of this study indicated that aggregates made from mine waste of Bafgh Ghoghart iron mine have better skid resistance compared to conventional limestone aggregates. Also, it was found that the problem of moisture sensitivity of these aggregates will be avoid by adding zycotherm and zycosoil. In addition to the technical advantages, the environmental benefits of using mines waste of Bafgh is considerable.

Researches show that the modification of bitumen with clay can enhance functional properties of asphalt mixtures, such as its resistance to heat, stability and flow. To use this characteristic of clay in cold recycled asphalt we can use clay modified bitumen emulsions. In these research two different types of bentonite is used to emulsify bitumen. Clay modified bitumen emulsion samples were made in laboratory and the agitation was provided by a high speed mixer. After quality control tests conducted, cold recycled asphalt samples were made with obtained emulsions. These samples were evaluated through functional tests such as Marshal Stability test, Indirect Tensile Strength and resilient modules in dry and saturated conditions. The results show that despite of improvements in resistance and strength characteristics of cold recycled asphalt with clay modified bitumen emulsions, they show weak performance in moisture conditions.

In this paper, stripping phenomenon in hot mix asphalt in Iran has been studied. For this purpose the effect of lime and three types of liquid anti stripping agents on two types of stone materials, sensitive against stripping phenomenon, has been investigated. The liquid antistripping agent in this research has been selected from one of the most credited producers in this field and the dampness sensitivity of materials has been measured through AASHTO T 283. The economic evaluation has been done according to cost-benefit method for application of antistripping agents. The results show that using lime and anti-stripping agents, it would be possible to modify two types of materials which are sensitive against stripping. But it is required to study each material separately for evaluation of the effect of anti-stripping agents. The economic analysis is descriptive of the fact that in some projects, the application of anti-stripping agents results reduced costs, in addition to technical upgrading of materials quality.

Stone matrix asphalt is one of the solutions for rutting used worldwide. By providing stone on stone contact, the coarse portion of this type of mixtures bear the loads of axles and transfer them to the lower layer. The mixture of fine aggregate, filler, bitumen and additive including fiber and polymers are to fill the air void of coarse aggregate. Bitumen must hold the coarse aggregates together. As the typical bitumen is not capable of doing so, the use of additive polymers seems essential. Additives consist of fiber and polymers. In order to prevent drain down while fabricating, cellulose fiber is used. The application of elastomer-thermoplastic polymers causes the improvement of rutting resistance in high temperature. Elastomeric properties make the deformations recoverable and thermoplastic properties broaden the performance grade of bitumen. Polyethylene and ethylene-vinyl-acetate copolymers are selected in dosage of 3, 5, 7 and 4, 8, 12 percent, respectively. These polymers could be directly added to the mixture which is a common method to use them in Iran. By applying 50℃ as the ambient temperature and 450KPa as the level of the stress for creep tests, while considering high temperature condition, the most severe condition of loading is simulated. Comparing the result of unconfined creep test which is performed on the modified and unmodified specimen, concluded that polyethylene and unmodified specimen has the same creep performance while 8 and 12 percent ethylene-vinyl-acetate has the same creep result as 4 and 6 styrene-butadiene-styrene specimens, respectively.

Using of Geotextiles is a solution to retard reflective cracking. In the recent decades, it has been concluded that by using of more resistant fibers such as glass fiber, it is possible to enhance the efficiency of Geotextiles. In this research, four points flexural beam test has been carried out to evaluate the effect of Geotextiles, which are reinforced by glass fibers, on fatigue life of asphalt specimens. There are three types of Geotextiles having the same type of fabric but different amount of glass fibers. It is shown that, in high strain cases, glass fibers are less efficient and therefore, it is much better using them at heavy traffic roads.

Growing urban development causes many problems in metropolitans such as increased traffic, air and noise pollution, congestion, lack of parking places for cars, especially in city centers, and this problem will affect most cities. Public parking lots are one of the major infrastructures of urban transportation system, which play a crucial role in reducing onstreet parking and traffic congestion. After selecting the study area, this study specified 20 effective criteria in positioning parking lots using experts’ opinions. A questionnaire was then prepared for the criteria effective in parking lots positioning. Finally, 11 criteria were applied to tackle the research. The AHP method was employed for weighting the selected criteria. To perform spatial analysis, the weights were applied to the layers made using the criteria on GIS. Quite suitable, suitable, unsuitable, and quite unsuitable places were specified for building parking lots within the study area using the overlay method. Statistical and library resources, detailed design drawings, and their statistics were used for data gathering. Research results showed that the parameters effective in parking lot positioning include three major criteria of anatomic-physical, socioeconomic, and access criteria and each consists of several sub-criteria. Land use criterion with the final weight of 0.24 and land area criterion with the final weight of 0.02 were recognized respectively as the major and minor criteria for positioning public parking lots. Finally, seven suitable places were determined after studying appropriate places in terms of mode of ownership. As the criteria effective in public parking lots positioning were determined with respect to different factors and the use of experts’ opinions and the criteria were analyzed using the conventional positioning method (the AHP method), this method could be recommended as an appropriate model for similar studies, especially on metropolises.

Nearly all the pavements in Iran are made of asphalt concrete. These pavements have short service life due to various reasons. One of the most specific destructions of asphalt pavements is the fatigue crack which occurs due to the numerous traffic loads on the roads. Geotextiles may act as reinforcing agents and increase the service life of asphalt pavements. In this research, three types of geotextiles are studied and their impact on the fatigue life of asphalt beams is investigated. The fatigue test has been implemented by 4 - point bending beam at constant strain condition with haversine wave, 10 Hz frequency. Results show that the fatigue life of all the specimens reinforced by Iranian and other geotextiles is increased, but this increase is higher for the foreign specimens compared to Iranian ones, and at various strain levels for any type of geotextile materials is different. The results also show that the average flexural stiffness of laboratory specimens may be increased or decreased by using geotextiles but totally geotextiles improve the quality of asphalt pavements.

During the last few decades, application of geotextile in asphalt concrete before laying it for the purpose of reducing the overlay thickness has drawn the attention of many researchers, therefore determination of its structural value is considered as an important issue.Falling Wight Deflectometer (FWD) is the most popular non - destructive test for thedetermination of asphalt overlay structural value. In this paper, to determine this value, twelve sections, 150 meters each, were studied on Tehran–Qom old road. Each section was tested twice (once before and once after the overlay implementation) and each time, at least 12 FWD tests were carried out. Overlay thickness was determined using the tests results. For the first time, a model has been developed to evaluate the asphalt overlay structural value using FWD test data of 5 sections with pure asphalt overlay (4 sections to develop the model and one to verify the output). The seven remaining sections were implemented using various popular, Iranian or foreign geotextiles as interlayers, and their structural values were determined by help of a developed model. Based on the outcome of the present research, the average structural value of overall geotextiles is equivalent to a 2.67 cm thick Hot Mix Asphalt (HMA) overlay while that of the Iranian ones equals 2.29 cm.