جستجوی مقالات مرتبط با کلیدواژه « بتن آسفالتی » در نشریات گروه « عمران »

In this research the effects of different aging conditions on the raveling and cracking resistance of asphalt concrete made by two types of aggregates, namely limestone and siliceous source have been investigated. Asphalt samples made by siliceous and limestone aggregates were made and were subjected to short-term and 5 and 7-day long-term aging conditions. After that, they were tested using Cantabro mass loss and semi-circular bending test at ambient temperature. Results reveal that the mixture made by limestone aggregates has more raveling and cracking resistance than the mixture made by siliceous aggregates. These results were found to be due to rougher texture and more angularity of limestone particles and also having more MgO and CaO content in their chemical compositions. Results also reveal that aging results in reduction of raveling resistance, fracture energy, fracture toughness, ductility and critical load sustained before fracture in semi-circular bending test. The effect of aging on these properties was found to be dependent on the type of aggregates and the considered property. In terms of raveling resistance, the aging is more effective on the mixture made by limestone aggregates; however, the fracture properties and cracking resistance of the mixture made by siliceous aggregates are more affected by aging than the mixture made by limestone aggregates.

In this study the effect of aggregate source on the ageing of asphalt binder ageing in asphalt mixtures has been investigated. Limestone and siliceous aggregates have been used for making specimens with the same binder and aggregate gradation. The mixtures were tested after subjecting to short and long term ageing, and the properties of the mixtures after each ageing condition have been evaluated and compared.  Marshall Stability, flow and Marshall Quotient (MQ), indirect tensile strength (ITS) and moisture susceptibility have been investigated. Results reveal that the mixture made by limestone aggregates has higher Marshall Stability, Marshall Quotient, and indirect tensile strength than the mixture made by siliceous aggregates, while the mixture made by siliceous aggregates has higher moisture susceptibility. The difference between the moisture susceptibility of the mixtures is more after ageing. Results also show that ageing results in increase of Marshall Stability, Marshall Quotient, the ITS in dry condition, and decrease of Marshall flow and tensile strength ratio.  It was found that long term ageing condition of 7 days at 85°C, results in 13 and 62% improvement in Marshall stability and ITS, respectively, in the mixture made by limestone aggregates, while these values for the siliceous aggregates are 17 and 32%. The effect of ageing on the Marshall Properties and moisture susceptibility for the mixture made by siliceous aggregates is higher than that for the mixtures made by limestone aggregates. However, the effect of ageing on the ITS in dry condition is higher for the mixture made by limestone aggregates.

This study aimed to investigate the properties of asphalt concrete containing reclaimed asphalt pavement (RAP) and waste polyethylene Teraphthalate (PET). Different dosages of PET including 0, 3, 6 and 9% (by the weight of total binder of control mix) were added to asphalt concrete containing 0, 10, 20 and 30% of RAP and the properties including Marshall stability and flow, indirect tensile strength (ITS), moisture damage resistance, dynamic creep and constant stress fatigue resistance have been evaluated. Results reveal that RAP inclusion improves Marshall Stability, resistance against permanent deformation, tensile strength and fatigue resistance. In addition, moisture sensitivity of asphalt mixture containing RAP is less than the control mix, and, for the mixtures containing the same PET content, inclusion of 20% RAP results in the highest tensile strength ratio (TSR). Results also show that PET results in decrease of Marshall Stability, permanent deformation and fatigue resistance. Moreover, in the mixtures containing the same RAP content, ITS and TSR of the mixtures containing 0 to 6% of PET are higher than those of the control mixture. From the results in this study it can be inferred that using RAP and PET simultaneously can result in better properties than the control mixture and using RAP allows using higher PET content without scarifying the properties.

this research aimed to investigate the effects of using waste polyethylene terephthalate (PET) on the resilient modulus of asphalt concrete. To this end, waste PET was added into asphalt concrete at different dosages of 0, 2, 4, 6 and 8% (by the weight of binder) and the resilient modulus of the mixtures was evaluated at different temperatures of 5, 25 and 45°C. Coarse and fine PET particles were added into asphalt concrete. Response surface methodology in Design Expert software was utilized for designing of experiments, developing a model for prediction of resilient modulus and evaluating the main and interaction effects of different factors on the resilient modulus of asphalt concrete. A polynomial model was well fitted to the test results relating temperature and PET content to the resilient modulus. Analysis of variance in Design Expert software implies that the model is highly capable for prediction of resilient modulus. Temperature, PET content and PET size are found to be effective on the resilient modulus. The resilient modulus of the mixtures was found to increase with increasing PET size and content, while it decreases with increasing temperature. However, the decrease of resilient modulus with PET size is not significant. It was found that there is no interaction between temperature and PET content with PET size, while interaction effect was found between temperature and PET content. Higher reduction of resilient modulus with increasing temperature was found to be in the mixtures containing higher PET content.

Flexible pavements is subjected to various combinations of repeated loading and varying environmental conditions that lead to their cracking. Induce healing technology of asphalt pavements under the electromagnetic radiation with electrically conductive particles is a novel method to heal the existing cracks of asphalt concrete materials. This research characterizes the mechanical and induced heating behavior of steel wool fiber (SWF) modified asphalt concrete considering induced healing technology. A microwave device was used to provide inductive heating in specimens. The electrical resistivity, Induce heating and healing and indirect tensile strength test were conducted on 0.2 and 1.5 (wt)% SWF modified asphalt concretes. The results indicated that SWF as a conductive component significantly decreased the electrical resistivity of asphalt concrete materials and is a potentially powerful additive for induction heating and healing purpose. Experimental tests demonstrated that not only the addition of 0.2 (wt)% SWF meets both the heating and healing requirements, but also it had considerably less negative effects on the mechanical performance of asphalt concrete comparing to the conventional 1.5% of SWF.

In this research, the effects of using different amounts of waste tire by dry and wet method, on the long term aging and moisture damage of a typical asphalt concrete have been investigated. Results show that in both methods of mixing, there is an optimum tire content by which the highest dry and conditioned indirect tensile strength is achieved. The optimum tire content for the dry and wet method was found to be 1 and 10%, respectively, by which, the indirect tensile strength in dry and wet method was found to be 20 and 18% higher than the control mixture. However, the conditioned indirect tensile strength of the mixtures containing the optimum rubber content in dry and wet method was found to be 0 and 17% higher than that of the control mixture. The experiments on the for both method mixing, the aged specimens  show that aging results in a slight increase in the indirect tensile strength of the control mixture and the mixtures containing different percentages of crumb rubber. Also the results show that long term ageing results in the increase of moisture susceptibility in the mixtures containing crumb rubber added by the wet method. However, the mixtures containing crumb rubber added by the dry method have a less susceptibility to moisture after long term ageing than that before long term ageing, for which a tensile strength ratio (TSR) of 0.98 was obtained.

Asphaltic concrete has been used as waterproofing core in embankment dams, since 1948. The large majority of embankment dams' central core is made of clay worldwide. However, as clay is increasingly difficult to find at new construction sites, asphalt concrete was used as a replacement core material. Cores made of clay has also some other disadvantages such as, low shear strength, compressibility, long construction time, requiring higher amount of material and accurate controls during construction, etc. These are in favor of using asphalt concrete, which has advantages such as less sensitivity to weather conditions, less width of core, healing behavior of bitumen, high shear strength etc. In this application, granular materials are used around the asphaltic concrete as filter, which makes a complicated behavior in the interface and needs to be researched by experiments and modeling. This paper describes experimental work and the results of investigating the mechanical behavior of the interface between aggregates and asphaltic concrete. Small scale shear strength test has been used in this study, in which the shear surface is considered as the interface. The effect of bitumen penetration grade, moisture, density and angularity of aggregates on the shear strength parameters at different levels of vertical stresses and a constant shear rate was studied.

In this research, in order to study the effect of using PET on the performance of asphalt concrete containing rubber modified and unmodified binder, PET particles were added into the mixtures in different dosages of 0, 2, 4, 6, 8 and 10% (by the weight of binder). After determination of the optimum binder content of the mixtures, the specimens were made and subjected to Marshall, indirect tensile and dynamic creep tests. The dynamic creep tests were performed using a universal testing machine (UTM-10) by applying a vertical stress of 300kPa at a temperature of 40°C, to investigate the resistance against permanent deformation. Results show that adding PET into the mixtures improves the Marshall stability and Marshall Quotient compared with those for the control mixture. However, the trend of variation with PET content is different for the unmodified and rubber modified mixtures. While the Marshall stability and Marshall quotient increase with increasing PET content in the rubber modified asphalt concrete, they reach to the highest value by adding 4% of PET into the unmodified mixture, and after that they decrease with increase of PET content. The indirect tensile test results show that the indirect tensile strength (ITS) of the mixtures made by rubber modified and unmodified binder and containing air voids content within 6.5 to 7.5%, reaches to its highest value by adding 2% of PET. However, for the mixtures containing air voids content within 3-5% ITS decreases with increasing PET content. Dynamic creep tests reveal that the resistance against permanent deformation decreases with increasing PET content in both mixtures, with a lower reduction in the mixtures made by rubber modified binder. Comparing the results of Marshall Quotient and dynamic creep tests show that the deformation behavior of PET modified mixtures is different under static and dynamic loading. While, the mixtures resistance against deformation under static loading is improved, under dynamic loading they show less resistance than the control mixtures. Also, results of this research show that PET is less effective on the rubber modified mixtures than the unmodified mixtures.  

Stripping and permanent deformation are two major modes of distress in asphaltic pavements. One of the measures to control these distresses is using additives, and, a variety of additives has been studied. In this research, the effect of two types of fiber on the moisture damage and permanent deformation properties of asphaltic concrete has been investigated. 38 mm long Polyester and 120 mm long polyacrylic fibers in different contents have been added to a typical asphaltic concrete and the permanent deformation behavior has been investigated by creep tests, and the moisture damage has been investigated by indirect tensile test in dry and saturated conditions. The results show that the fibers improve the permanent deformation behavior of asphalt concrete. However, while the polyester fibers improve the moisture damage property of the mixture, the polyacrylic fibers decreases the ratio of the saturated to dry indirect tensile strength of the mixture.

Buckling and geometric variation of railway track are the phenomena that threaten railway stability. The lateral resistance is the factor that maintains stability of railway track against them. In ballasted tracks، there are some regions that lateral forces increase، for example، in areas with high differences in temperature or in curves with low radii. In these places، the train speed will be restricted for keeping lateral stability. This approach will decrease the capacity of passengers and freight train transition. A lot of investigations by different researchers were carried out by using beam model or Euler theory Such as Kerr 1999 and Kish et al [1]. Other experimental and field studies have been done by Plasser and Theurer studies، Le pen and some Msc Dissertations in School of Railway engineering (SRE) of Iran University of Science and Technology (IUST). In this school a lot of bachelor and master thesis with this base defined and carried out. In related with numerical study of lateral resistance، there are limited studies like an article with subject “A numerical study of the lateral ballast resistance in railway tracks” presented by Kabo [2]. The technical investigation showed that different parameters affect the lateral resistance such as type and weight of sleeper (winged sleeper، frictional sleeper etc.)، ballast density، fouling، extent and material of ballast layer. This paper presents an innovative approach with using concrete asphalt in ballast shoulder that will increase lateral stability of railway. In this approach ballast material in shoulder substitutes with concrete asphalt and performance of shoulder will be evaluated.

Asphalt cracking is one of the major distress and deterioration modes of pavements of roads especially in the cold regions. Different types of cracks such as top-down، reflecting and alligator cracks are usually observed in the asphalt pavements. These cracks may be initiated due to improper construction and implementation of paving process، daily or seasonal cyclic thermal loads and mechanical traffic loading induced by moving vehicles. Consequently، the investigation of crack growth behavior in the asphalt overlays is an important issue for design، construction and maintenance of roads and highways. Due to the applied thermal and mechanical stresses، the cracks initiated in the asphalt layers may often experience different deformations including mode I (tensile or opening)، mode II (shear or sliding) and any combinations of opening-shearing deformations (i. e. mixed mode I/II). Fracture toughness is a key fundamental parameter for investigating the crack growth behavior of cracked bodies. From the other hand، since asphalt mixtures are composite materials composed of aggregate، binder and air void، their fracture behavior might be affected by the asphalt characteristics specifications. Hence in this research the influences of asphalt characteristic specifications (including the type and size of aggregates، bitumen type، air void content and the mixture composition) is investigated experimentally on the mixed mode fracture toughness of different asphalt mixtures. For conducting the fracture toughness experiments، semi circular bend (SCB) specimens containing a vertical edge crack and subjected to asymmetric three-point bend loading was used. In order to study the influence of mixture characteristic specifications on the value of fracture toughness، two aggregate types (i. e. limestone and siliceous)، two aggregate sizes (with nominal maximum aggregate sizes 19 mm and 4. 75 mm)، two binders (60/70 and 85/100) and two air void percentages (i. e. 4% and 6%) were considered for manufacturing asphalt mixtures. The SCB specimens were then tested under two different loading mode mixities (i. e. Me = 0. 8 (mixed mode condition with dominantly tensile deformation) and Me = 0. 38 (mixed mode condition with dominantly shear deformation) at -15oC. The load-displacement curves for the whole samples were linear which revealed the linear and elastic behavior of asphalt mixtures at the tested low temperature. Thus، the corresponding values of fracture toughness (KI، KII and Keff) were determined using the obtained fracture loads and the available formula. The experimental result showed that the mixed mode cracking resistance of asphalt mixtures is significantly affected by their properties. Analysis of results indicated that the specimens containing 4% air void (i. e. with the more compacted mixtures) show greater resistant against cracking than the asphalt specimens containing 6% air void. Meanwhile by increasing the maximum aggregate size the fracture toughness is also increased. Mixtures made of limestone aggregates and softer binders had more fracture toughness. Analysis of results also showed that when the contribution of mode II deformation is increased، the influence of air void and aggregate size on the fracture toughness of tested asphalt mixtures becomes negligible.

The main objective of this research is to analyze the fatigue life and resistance against fatigue cracks of asphalt mixtures modified by nanosilica at intermediate temperatures. In this research،4 % and 6 % nanosilica (by weight of base binder) was added to binder. We made use of resilient modulus، indirect tensile strength and 4-point bending beam fatigue experiments to evaluate the modified asphalt mixture resistance and fatigue life. The results showed that the nanosilica modified asphalt binder significantly improved the fatigues life and the resistance of the asphalt mixture against fatigue cracks at intermediate temperatures. Adding nanosilica led to a significant increase in the indirect tensile strength and resilient modulus. The results of the 4-point bending beam fatigue test showed that the addition of nanosilica increased the fatigue life of the asphalt mixture. Therefore، it can be safely stated that adding nano-silica reduces fatigue cracks، and increases fatigue life and resistance of asphalt mixtures at intermediate temperatures.

A‌s‌p‌h‌a‌l‌t‌i‌c c‌o‌n‌c‌r‌e‌t‌e h‌a‌s b‌e‌e‌n u‌s‌e‌d a‌s a w‌a‌t‌e‌r‌p‌r‌o‌o‌f‌i‌n‌g c‌o‌r‌e f‌o‌r e‌m‌b‌a‌n‌k‌m‌e‌n‌t d‌a‌m‌s s‌i‌n‌c‌e 1948. W‌o‌r‌l‌d‌w‌i‌d‌e, t‌h‌e l‌a‌r‌g‌e m‌a‌j‌o‌r‌i‌t‌y o‌f t‌h‌e e‌m‌b‌a‌n‌k‌m‌e‌n‌t d‌a‌m c‌e‌n‌t‌r‌a‌l c‌o‌r‌e i‌s m‌a‌d‌e o‌f c‌l‌a‌y. H‌o‌w‌e‌v‌e‌r, a‌s c‌l‌a‌y i‌s i‌n‌c‌r‌e‌a‌s‌i‌n‌g‌l‌y d‌i‌f‌f‌i‌c‌u‌l‌t t‌o f‌i‌n‌d a‌t n‌e‌w c‌o‌n‌s‌t‌r‌u‌c‌t‌i‌o‌n s‌i‌t‌e‌s, a‌s‌p‌h‌a‌l‌t c‌o‌n‌c‌r‌e‌t‌e h‌a‌s b‌e‌e‌n u‌s‌e‌d a‌s a r‌e‌p‌l‌a‌c‌e‌m‌e‌n‌t c‌o‌r‌e m‌a‌t‌e‌r‌i‌a‌l. C‌o‌r‌e m‌a‌d‌e o‌f c‌l‌a‌y h‌a‌s s‌o‌m‌e f‌u‌r‌t‌h‌e‌r d‌i‌s‌a‌d‌v‌a‌n‌t‌a‌g‌e‌s, s‌u‌c‌h a‌s; l‌o‌w s‌h‌e‌a‌r s‌t‌r‌e‌n‌g‌t‌h, c‌o‌m‌p‌r‌e‌s‌s‌i‌b‌i‌l‌i‌t‌y, l‌o‌n‌g c‌o‌n‌s‌t‌r‌u‌c‌t‌i‌o‌n t‌i‌m‌e, r‌e‌q‌u‌i‌r‌i‌n‌g h‌i‌g‌h‌e‌r a‌m‌o‌u‌n‌t‌s o‌f m‌a‌t‌e‌r‌i‌a‌l, a‌n‌d a‌c‌c‌u‌r‌a‌t‌e c‌o‌n‌t‌r‌o‌l‌s d‌u‌r‌i‌n‌g c‌o‌n‌s‌t‌r‌u‌c‌t‌i‌o‌n, e‌t‌c. T‌h‌e a‌d‌v‌a‌n‌t‌a‌g‌e‌s o‌f u‌s‌i‌n‌g a‌s‌p‌h‌a‌l‌t c‌o‌n‌c‌r‌e‌t‌e a‌r‌e; l‌e‌s‌s s‌e‌n‌s‌i‌t‌i‌v‌i‌t‌y t‌o w‌e‌a‌t‌h‌e‌r c‌o‌n‌d‌i‌t‌i‌o‌n‌s, l‌e‌s‌s w‌i‌d‌t‌h o‌f c‌o‌r‌e, t‌h‌e h‌e‌a‌l‌i‌n‌g b‌e‌h‌a‌v‌i‌o‌r o‌f b‌i‌t‌u‌m‌e‌n a‌n‌d h‌i‌g‌h s‌h‌e‌a‌r s‌t‌r‌e‌n‌g‌t‌h e‌t‌c. I‌n t‌h‌i‌s a‌p‌p‌l‌i‌c‌a‌t‌i‌o‌n, g‌r‌a‌n‌u‌l‌a‌r m‌a‌t‌e‌r‌i‌a‌l‌s a‌r‌e u‌s‌e‌d a‌r‌o‌u‌n‌d t‌h‌e a‌s‌p‌h‌a‌l‌t‌i‌c c‌o‌n‌c‌r‌e‌t‌e a‌s a f‌i‌l‌t‌e‌r, w‌h‌i‌c‌h c‌r‌e‌a‌t‌e‌s c‌o‌m‌p‌l‌i‌c‌a‌t‌e‌d b‌e‌h‌a‌v‌i‌o‌r a‌t t‌h‌e i‌n‌t‌e‌r‌f‌a‌c‌e a‌n‌d w‌h‌i‌c‌h n‌e‌e‌d‌s t‌o b‌e r‌e‌s‌e‌a‌r‌c‌h‌e‌d b‌y e‌x‌p‌e‌r‌i‌m‌e‌n‌t a‌n‌d m‌o‌d‌e‌l‌i‌n‌g. T‌h‌i‌s p‌a‌p‌e‌r d‌e‌s‌c‌r‌i‌b‌e‌s t‌h‌e e‌x‌p‌e‌r‌i‌m‌e‌n‌t‌a‌l w‌o‌r‌k a‌n‌d t‌h‌e r‌e‌s‌u‌l‌t‌s o‌f i‌n‌v‌e‌s‌t‌i‌g‌a‌t‌i‌n‌g t‌h‌e m‌e‌c‌h‌a‌n‌i‌c‌a‌l b‌e‌h‌a‌v‌i‌o‌r o‌f t‌h‌e i‌n‌t‌e‌r‌f‌a‌c‌e b‌e‌t‌w‌e‌e‌n a‌g‌g‌r‌e‌g‌a‌t‌e‌s a‌n‌d a‌s‌p‌h‌a‌l‌t‌i‌c c‌o‌n‌c‌r‌e‌t‌e. A s‌m‌a‌l‌l s‌c‌a‌l‌e s‌h‌e‌a‌r s‌t‌r‌e‌n‌g‌t‌h t‌e‌s‌t h‌a‌s b‌e‌e‌n u‌s‌e‌d i‌n t‌h‌i‌s s‌t‌u‌d‌y, i‌n w‌h‌i‌c‌h t‌h‌e ‌h‌e‌a‌r ‌u‌r‌f‌a‌c‌e ‌s ‌o‌n‌s‌i‌d‌e‌r‌e‌d a‌s t‌h‌e i‌n‌t‌e‌r‌f‌a‌c‌e. T‌h‌e e‌f‌f‌e‌c‌t o‌f b‌i‌t‌u‌m‌e‌n p‌e‌n‌e‌t‌r‌a‌t‌i‌o‌n g‌r‌a‌d‌e, m‌o‌i‌s‌t‌u‌r‌e, d‌e‌n‌s‌i‌t‌y a‌n‌d a‌n‌g‌u‌l‌a‌r‌i‌t‌y o‌f a‌g‌g‌r‌e‌g‌a‌t‌e‌s o‌n t‌h‌e s‌h‌e‌a‌r s‌t‌r‌e‌n‌g‌t‌h p‌a‌r‌a‌m‌e‌t‌e‌r‌s a‌t d‌i‌f‌f‌e‌r‌e‌n‌t l‌e‌v‌e‌l‌s o‌f v‌e‌r‌t‌i‌c‌a‌l s‌t‌r‌e‌s‌s‌e‌s a‌n‌d c‌o‌n‌s‌t‌a‌n‌t s‌h‌e‌a‌r r‌a‌t‌e w‌a‌s s‌t‌u‌d‌i‌e‌d. A‌s‌p‌h‌a‌l‌t c‌o‌n‌c‌r‌e‌t‌e s‌p‌e‌c‌i‌m‌e‌n‌s w‌e‌r‌e c‌u‌t i‌n s‌q‌u‌a‌r‌e s‌h‌a‌p‌e‌s (10ش10ش2. 5c‌m) f‌r‌o‌m c‌y‌l‌i‌n‌d‌r‌i‌c‌a‌l s‌p‌e‌c‌i‌m‌e‌n c‌o‌m‌p‌a‌c‌t‌e‌d b‌y a m‌o‌d‌i‌f‌i‌e‌d m‌a‌r‌s‌h‌a‌l c‌o‌m‌p‌a‌c‌t‌i‌o‌n m‌e‌t‌h‌o‌d. T‌h‌e r‌e‌s‌u‌l‌t‌s s‌h‌o‌w t‌h‌a‌t t‌h‌e s‌h‌e‌a‌r s‌t‌r‌e‌n‌g‌t‌h p‌a‌r‌a‌m‌e‌t‌e‌r‌s i‌n‌c‌r‌e‌a‌s‌e w‌i‌t‌h i‌n‌c‌r‌e‌a‌s‌i‌n‌g t‌h‌e d‌e‌n‌s‌i‌t‌y a‌n‌d v‌e‌r‌t‌i‌c‌a‌l s‌t‌r‌e‌s‌s l‌e‌v‌e‌l. I‌t i‌s a‌l‌s‌o s‌h‌o‌w‌n t‌h‌a‌t t‌h‌e s‌h‌e‌a‌r p‌a‌r‌a‌m‌e‌t‌e‌r‌s d‌e‌c‌r‌e‌a‌s‌e w‌i‌t‌h i‌n‌c‌r‌e‌a‌s‌i‌n‌g m‌o‌i‌s‌t‌u‌r‌e c‌o‌n‌t‌e‌n‌t i‌n t‌h‌e i‌n‌t‌e‌r‌f‌a‌c‌e. T‌h‌e p‌e‌n‌e‌t‌r‌a‌t‌i‌o‌n g‌r‌a‌d‌e o‌f b‌i‌t‌u‌m‌e‌n d‌o‌e‌s n‌o‌t h‌a‌v‌e a s‌i‌g‌n‌i‌f‌i‌c‌a‌n‌t e‌f‌f‌e‌c‌t o‌n t‌h‌e p‌a‌r‌a‌m‌e‌t‌e‌r‌s. I‌t i‌s a‌l‌s‌o d‌e‌m‌o‌n‌s‌t‌r‌a‌t‌e‌d t‌h‌a‌t t‌h‌e r‌a‌t‌i‌o o‌f i‌n‌t‌e‌r‌a‌c‌t‌i‌o‌n b‌e‌t‌w‌e‌e‌n t‌h‌e a‌g‌g‌r‌e‌g‌a‌t‌e a‌n‌d a‌s‌p‌h‌a‌l‌t c‌o‌n‌c‌r‌e‌t‌e d‌e‌c‌r‌e‌a‌s‌e‌s i‌n a c‌e‌r‌t‌a‌i‌n r‌a‌n‌g‌e o‌f v‌a‌r‌i‌a‌t‌i‌o‌n.

In the present article, static and dynamic behavior of asphalt concrete materials serve as an element in Bbnd Sngryz·hyy earth dams have been studied. Bdynmnzvr large number of experiments and Dvrhyy Mvnvtvnyk using the MTS Dynamic Research Institute in Norway was NGI. Experiments in temperature, stresses comprehensive, dissonance, and various loadings is done quickly. Determination of dynamic parameters and type of asphalt concrete Rftarmsalh Dvrhyy loads applied at the time and the impact of different parameters such as temperature, tension, dissonance and the speed of loading of the goals of this study is. To study the behavior of these materials, several experiments Dvrhyy Mvnvtvnyk immediately after testing conducted on some samples and samples treated curves before and after loading are compared. Results of tests conducted indicate the appropriate behavior of asphalt concrete materials against dynamic loads and even after the period of loading thousands significant reduction in the resistance of this material is not observed.

The vehicle load repetition on the pavements leads to further deflections due to the material softening and the reduction of pavement stiffness. In this research, the stiffness reduction studied using a back analysis of surface bowls under wheel load. In this back analysis the visco-elastoplastic model and the finite element method used. There seems to be no evidence of evaluating the stiffness reduction of pavements using visco-elastoplastic modeling of asphalt concrete behavior. The results indicated that this modeling approach provides a more accurate predication of performance and useful cycle life of asphalt mixtures when compared to the visco-elastic models.