فهرست مطالب علیرضا عاملی

The objective of this study is to investigate the effect of using Pozzolan as an asphalt binder modifier and assess its potential physical and rheological improvements. This research also intends to initiate a comprehensive research on the effect of Pozzolan on the rheological characteristics of asphalt binder since only limited studies have used Pozzolan as an asphalt binder modifier. Pozzolan was added to a (60/70) penetration grade asphalt binder at six different percentages in addition to the control asphalt binder. Both traditional and rheological tests on modified and control asphalt binders were performed. The traditional tests included penetration, softening point, ash and re points, and ductility. The rheological tests, on the other hand, included rotational viscometer (RV) and Dynamic Shear Rheometer (DSR) tests. The outcomes proved that adding Pozzolan to asphalt binder enhanced high-temperature performance. 15% Pozzolan content was found to be the optimum content at which most rheological characteristics of the asphalt binder were enhanced. The experimental outcomes were contrasted and analyzed statistically by the analysis of variance (ANOVA) to discover any significant difference between the influence of Pozzolan and test temperature. The outcomes of one-way ANOVA pointed out that Pozzolan had a significant influence on the rotational viscosity and physical characteristics. Also, the change in Pozzolan content and temperature together showed a significant effect on the rutting parameter according to the two-way ANOVA outcomes.

In order to investigate the effect of the percentage of nanoparticles, storage time and storage temperature on the storage stability of bitumen modified by nanoparticles, storage tests, softening point tests and dynamic shear rheometer 1 (DSR) tests were used to evaluate the characteristics of two types of bitumen modified with nanotitanium dioxide (TiO2). Became The results showed that the softening point, fracture temperature, dynamic shear viscosity and |𝐺∗|/sin(𝛿) of bitumen’s increase with the percentage of nanoparticles. The storage stability of bitumens decreased with the percentage of nanoparticles. The effect of storage time on the storage stability of bitumen’s was significant when the storage time was more than 48 hours. In addition, the storage stability of bitumen’s at low temperatures was better than at high temperatures. The reduction of nanoparticle size due to nanoparticle aggregation could not effectively increase the storage stability of nanoparticle-modified bitumen.

Modification plays an important role in asphalt deterioration. Failure occurs when bitumen separates from aggregate particles due to reduced adhesion between asphalt and aggregate compared to adhesion between water and aggregate. In recent years, the use of nanomaterials can be used to improve various asphalt properties. In this study, three types of nanoclay were used to modify styrene-butadiene-styrene modified bitumen (SBS1-). The resistance to failure of modified bitumen was evaluated using surface free energy (SFE2). The results showed that the SFE decreased and the energy ratio (ER3) increased by modifying bitumen with nanoclays, indicating that nanoclays can improve the resistance of these aggregate cohesive systems. After immersion, due to the interaction between water and bitumen, the subsequent degradation rate was observed in both SBS and nanoclay modified asphalt. However, the residual amount of 3D structures in nanoclay modified asphalt was higher than that of SBS modified asphalt, indicating that nanoclay makes the surface morphology more resistant to water damage. Finally, freezing and melting tests were used for the results obtained through SFE tests.

Recycled asphalt pavement (RAP) has become a common practice in most countries. Hence, the use of rejuvenators along with RAP has become popular with asphalt producers, mainly due to rising raw material costs. In this study, crumb rubber (CR) 2 and waste frying oil (WFO) 3 were used to restore the properties and increase the rutting resistance of RAP. Several physical and rheological properties of bitumen were tested. The results showed that the RAP bitumen samples containing WFO and CR reduce the softening point and increase the degree of penetration. This is related to increasing penetration index. In addition, the viscosity of WFO/CR composite recycled bitumen showed better workability and hardness, as well as low storage stability temperature (less than 2.2 °C) with an acceptable decrease during heating. The rheological properties of WFO/CR with regenerated bitumen were comparable to the control sample. The incorporation of CR with WFO as a hybrid rejuvenator increased the rutting resistance. Therefore, the presence of WFO/CR has a significant effect on the properties of RAP bitumen, while creating a better environment and reducing environmental pollution by reusing waste materials.

In order to improve the quality of road performance and solve the problem of deterioration in normal asphalt pavement during service, in this research, a 5.3% aluminate agent was used to modify the surface of nano zinc oxide and prepare composite modified asphalt with nano oxide and basalt fiber 1 (BF). It was used as a modifier. First, the initial performance of the different types was examined. Then, a dynamic shear rheology test was conducted to analyze the high temperature rutting performance of composite modified asphalt at different temperatures and frequencies. Then, using the flexural creep hardness test, the low temperature properties of asphalt modified with composite were investigated. The results show that the aging performance of asphalt modified with ZnO/BF nanocomposite is significantly improved after adding fibers to the modified asphalt. The average mass loss ratio is only 0.192%. At 46°C, the rutting coefficient of composite-modified asphalt increased by 62.3%. The main frequency curve is always at the highest position and continues to increase, indicating a significant improvement in the high-temperature rutting performance of the composite-modified asphalt. At 24°C, the S value of the creep modulus of asphalt modified with composite increased by 24.9%. In addition, there is no obvious effect of low temperature improvement, but the range of variation of creep tangent slope m of modified asphalt is reduced after aging, which further indicates that the addition of a modifier can reduce the effect of aging on asphalt.

In this paper, to prepare modified bitumen, bitumen was mixed with 0%, 4%, 6% and 8% amorphous poly alpha olefin (APAO). Based on the tests of penetration degree, flexibility, softening point and dynamic shear rheometer test (DSR), the amount of 6% APAO was determined as the optimal percentage in terms of bitumen performance. Continuously graded stone materials were mixed with APAO in order to prepare mixtures modified with APAO. The volumetric parameters of asphalt mixture with bitumen modified with APAO were tested. Standard Marshall Strength test, saturated Marshall Test, post-frost cracking test and Marshall Strength test of asphalt mixtures after aging were performed on asphalt mixtures with bitumen modified with APAO. Based on the Marshall Strength test, saturated Marshall Test and post-frost cracking test, the asphalt mixture with 6% APAO had better performance at high temperatures, more resistance to moisture damage and reduced minimum tensile strength after frost conditions. Tensile strength decreased after adding APAO. The difference in tensile strength between asphalt mixture with 4% APAO and 6% APAO was only negligible. Based on the Marshall Strength and Marshall Strength ratio (RMSR) 3 of the asphalt mixtures after aging, the optimal amount of APAO was 6%. Therefore, 6% APAO was determined as the optimum amount for both modified bitumen and asphalt mixture with APAO.

Due to the problems of high cost, difficult processing and unfavorable storage stability of bitumen modified with 1SBS, a lot of research has been done on composite bitumen to achieve superior pavement performance. In this study, the asphalt mixture was modified by nanosilica, gilsonite and SBS. Asphalt binder main performance tests, rutting tests, low temperature bending tests, moisture sensitivity tests, fatigue tests, and durability tests of asphalt mixture modified with SBS, gilsonite, nanosilica/rock asphalt, and nanosilica/ gilsonite/SBS were conducted to determine the performance Their structure should be evaluated. By comparing the results of the tests with the properties of the unmodified asphalt mixture, nano-silica and stone asphalt led to the improvement of the structure performance. The modified asphalt mixture with nanosilica/gilsonite/SBS had higher stability temperature, low temperature cracking resistance, lower moisture sensitivity, and longer durability than asphalt binder modified with 5% SBS, except for similar fatigue life.

The goal of the current investigation was to determine how nanosilica particles affected the performance parameters of asphalt binders treated with polymers. In this investigation, nanosilica particles and polypropylene polymer were added at concentrations ranging from 0% to 4% to regulate 80/100 binder. By weight, polypropylene polymer and nanosilica particles were added to the total bitumen content. To assess the impact of nanosilica particles, asphalt performance tests such as the flexural four point beam fatigue test, indirect tensile strength, indirect tensile stiffness modulus, and draindown tests are carried out. The study's findings demonstrate that adding nanosilica particles to a modified polypropylene polymer binder increases its resistance to fatigue. This suggests that the performance characteristics of binders modified with polymers are significantly improved by nanosilica particles. The outcome also shows that bitumen modifiers made of thermoplastic polymer polypropylene and nanosilica particles enhance the functionality and longevity of asphalt mixes.

The current study examined the properties of warm mixture asphalt (WMA), which contains nano- and polypropylene polymer (PP) polymers. Unmodified WMA and modified WMA both include 3% PP and NS (2–5%) by weight of asphalt respectively. The tests used to assess performance include the tests for fatigue resistance, rutting resistance, and moisture resistance. The results show that adding Nano-silica and Polypropylene enhances WMA performance. The results also show that adding polypropylene and nano-silica to asphalt as modifiers increases the asphalt's performance and durability.

Ever-growing concern to protect the environment concentrated the attention of the society on the possible re-use of different agricultural and industrial wastes in road construction. This research study depicts the effect of using wastes like rice husk ash (RHA) and fly ash (FA) as a replacement of conventionally used hydrated lime (HL) as fillers in hot-mix asphalt (HMA). Primarily, the dense graded bituminous macadam (DBM) mix specimens were made in the laboratory with varying proportions ranging from 2% to 8% of HL, RHA and FA by following design mixes according to the Marshall method and compared the results with control mix as prepared by utilizing 2% HL. The performances of the said mixes were studied through the Marshall Quotient, indirect tensile strength and tensile strength ratio. Results of investigation show better performance of HMA with the addition of RHA and FA and also proved to be economical as the optimum bitumen content is reduced by 7.5% from that of control mix when added at 4% filler ratio. Further, RHA shows a greater affinity to the bitumen attributing the highest stiffening effect of the bituminous mastic droplets compared to that of other used fillers with good compatibility at the micro level by satisfying the essential criterion.

Nanomaterials have indicated a hopeful capacity in improving the behavior of pavement. As hot mix asphalt is a viscoelastic material, several distresses were occurred during their life time. Furthermore, steel slag was used to enhance the properties of mixture because of its outstanding physical properties. This research evaluated the effect of nanoclay and Styrene Butadiene Rubber (SBR) on performance behavior of bitumen and high and intermediate temperature performance of SMA mixtures containing steel slag aggregate. Through this paper, the AC-60/70 and AC-85/100 penetration grade bitumen’s were used as base bitumen. Moreover, SBR (0%, 2%, 4%, 6%, 8% and 10% by weight of binder), and nanoclay (0%, 1%, 2%, 3%, 4%, and 5% by weight of binder) were used as a mixture modifier. For evaluating the performance behavior of bitumen, the rotational viscosity, Dynamic Shear Rheometer (DSR), and Bending Beam Rheometer (BBR), Multiple Stress Creep Recovery (MSCR), and linear Amplitude Sweep (LAS) tests were implemented. Moreover, Resilient Modulus (Mr), Indirect Tensile Strength (ITS), dynamic creep, wheel track, and Four Point Beam Fatigue (FPBF) tests were performed to investigate the performance of mixture samples. To analyze the data statistically, two-factor analysis of variance (ANOVA) is evaluated. The rheological behavior test outcomes showed that the utilization of NC/SBR additive results in an enhancement in the rutting and fatigue resistance of binders. The utilization of NC decreases the low-temperature resistance of binders, while SBR improves the bitumen’s low-temperature resistance. Storage stability test outcomes reveal that utilization of NC enhances the storage stability of binders. Also, the application of SBR leads to enhance phase separation. The MSCR test results demonstrate an enhancement in the high-performance temperature of the virgin binder at different stress levels by the addition of NC/SBR. Moreover, the utilization of NS improves the rutting strength of samples. Based on the LAS test outcomes, the utilization of NC/SBR additives improves the fatigue properties of the asphalt binder. The mixture test results reveal that using NC/SBR increases the permanent deformation resistance, MR, ITS, fracture energy, and intermediate temperature properties of specimens.

In this paper, using rice husk ash (RHA) in hot mix asphalt (HMA) as filler was evaluated. The main aim of replacing mineral filler is enhancing the performance of asphalt mixes and producing an economical asphalt mix. For this purpose, five different mixes were prepared; the first was a control mix (traditional mix) containing 100% Lime Stone Dust (LSD) as filler and 0% RHA. While, the other mixes contain 25%, 50%, 75% and 100% of RHA as a percentage of the filler weight. Optimum bitumen content (OBC) was determined using Marshall test, also all Marshall parameters (Stability, Air Voids, Voids in Mineral Aggregate, Unit Weight and Flow) were examined. Indirect Tensile Strength Test (ITST) and Wheel Tracking Test (WTT) were conducted and their results were analyzed. Dynamic modulus (│E*│) is considered an important parameter used in mechanistic-empirical pavement design. The │E*|is measured at different temperature/frequency combinations. Dynamic modulus (│E*│) and phase angle (δ) are used for the visco- elastic characterization of HMA. Thus, these properties were measured for mixes with and without RHA. The results indicate that RHA has the potential to be used as partial substitution of mineral filler LSD in pavement construction. Adding RHA enhances Marshall stiffness, reduces rut depth and increases indirect tensile strength values. Further, a significant change has been occurred in OBC for all mixes and the optimum replacement ratio is recorded as 50% RHA: 50% LSD. Finally, mixes containing RHA show higher dynamic modulus values and flow number.

Composite modification is increasingly used to alleviate the detrimental problems associated with asphalt modifiers and meet the massive demand for asphalt pavement. In this study, nano-Al2O3 composite modifications at three concentrations of 1%, 2%, and 3% by weight of asphalt binder were implemented in neat and modified asphalt binders to improve their performance at high and intermediate temperatures. These binders were evaluated in terms of their physical, rheological, and high-temperature storage stability properties. In addition, nano-Al2O3 composite modified binders were utilized in asphalt concrete and investigated for their resistance to cracking, permanent deformation, and moisture damage. The nano-Al2O3 composite modifications were made using neat, polymer-modified, and crumb-rubber (CR) modified asphalt binders. Adding nano-Al2O3 to the asphalt binders was found to improve stiffness, high-temperature storage stability, permanent deformation resistance, and cracking tolerance. Moreover, the composites of nano-Al2O3 with neat and modified asphalt binders were found to provide improved resistance to permanent deformation, cracking, and moisture damage in hot mix asphalt concrete. The composite of 2% nano-Al2O3 showed the best performance in terms of resistance to permanent deformation, the composite of 3% nano-Al2O3 showed the best performance in terms of resistance to moisture damage, the composites of 2% nano-Al2O3 with polymer and CR-modified asphalt binders both showed the best performance in terms of resistance to cracking, and the composite of 3% nano-Al2O3 with AC20 showed improved resistance to cracking.

Asphalt pavements are one of the most widely constituents utilized to pave highway pavement which experience various failures during their lifetime, such as rutting, fatigue and thermal cracking. Therefore it should be used to improve the bitumen performance by addition of modifiers such as polymers and Nano Clays (NC). Among the various additives used to improve the bitumen performance, Ethylene Vinyl Acetate (EVA) is one of the most useful and effective materials for paving. In this study, the rheological behavior of bitumen and rutting and fatigue behavior of mixture containing EVA/Nanoclay and EVA latex were evaluated. EVA/NC and EVA latex were made and mixed with bitumen. Results of storage stability test shown that EVA/NC-modified bitumen is steadier than EVA-latex-modified bitumen. The results of the fatigue test of the mixtures showed that the asphalt mixtures made of bitumen modified with nanocomposite are more resistant to fatigue than bitumen modified with EVA polymer. The results showed that the addition of 6% EVA/NC and 6% EVA increased the fatigue life by 43% and 20%, respectively. The results of the rutting resistance tests showed that the rutting resistance of the samples increased with the increase of EVA polymer. Also, the addition of montmorillonite increased the resistance of polymer mixtures against rutting.

In this study, an attempt has been made to investigate how the rheological behaviors of bitumen are affected by the use of lignin and soybean oil. In the current research, lignin (3%, 5%, 7% by weight of bitumen) and soybean oil (5% by weight of bitumen) were added to modify two main types of bitumen (AC 60-70 and AC 85/100). The performance evaluation of different bitumen was evaluated by examining their physical and rheological behavior by penetration tests, ductility, linear range sweep, multiple stress creep recovery, dynamic shear remoter, rotational viscosity and softening point tests. The results of rheological behaviors showed that the use of lignin additive increases the softening point and decreases the degree of penetration. The use of lignin reduces the low-temperature strength of the bitumen, while oil improves the low-temperature strength of the bitumen. The results of the multiple stress creep recovery (MSCR) test with the addition of lignin showed an increase in the high yield temperature of virgin bitumen at different stress levels. While the use of oil reduces the creasing strength of the sample. According to the results of the linear range sweep (LAS) test, the use of lignin additive reduces the fatigue properties of bitumen. While soybean oil strengthened it.

The performance properties of bitumen and asphalt mixtures can be improved by using several modifiers, including: poly phosphoric acid (PPA1), semi-hot asphalt mixture modifiers (WMA2) and styrene butadiene rubber (SBR3). The present study evaluated the effect of PPA and WMA contents on the functional properties of SMA4 mixture. The modified SBR / PPA and SBR / PPA / WMA mixtures were subjected to indirect tensile strength tests (ITS5), dynamic creep, elastic modulus (Mr6), wheel path and four-point beam fatigue (FPB7). Two-factor analysis of variance (ANOVA8) was used to analyze the data. According to the results, the use of SBR and PPA increases the properties of Mr, grooved, ITS, FE and fatigue behavior of the samples. As the percentage of PPA increases, caries and fatigue behavior increase. While reducing Mr and IT’S of modified mixtures. Among hot additives, Sasobit has a better effect on increasing the performance of bitumen and mixtures.

Warm-mix asphalt (WMA), which reduces the production temperatures (mixing and compaction), while maintaining the advantages of hot-mix asphalt (HMA), is becoming an attractive paving material. In this study, rheological properties of two commonly used performance grade (PG) binders (PG 64-22 and PG 70-28) were evaluated, with and without Sasobit and Aspha-Min additives. For PG 64-22, 2%, 3%, and 4% Sasobit additive reduced the mixing temperature of the pure binder from 163°C to 147°C (i.e., by 16°C). In case of the PG 70-28, the reductions are 10°C, 12°C and 13°C, respectively, for 2%, 3%, and 4% Sasobit additive. No significant decrease in mixing temperature by the Aspha-Min additive was observed in using the rotational viscometer. Evaluation of the binders on the basis of G*/sin () demonstrates no negative effect on high-temperature grading due to high-temperature viscosity reduction. With the addition of 4% Sasobit additive, the high-temperature binder grading of PG 64 (actually PG 65) increases to PG 69, while 4% Sasobit additive improves the PG 70 (actually PG 75) to PG 80. No significant changes in grading were observed with the addition of the Aspha-Min additive. In fact, reduction in binder viscosity and improvement in binder grading with- out increasing the viscosity indicate two-way reductions (both direct and indirect) in production temperatures by the Sasobit additive. Finally, the Sasobit additive is found to decrease the asphalt pavement analyzer rut depths significantly, and these rut depths correlate well with the rutting factor G*/sin(). It was also observed that rutting potential decreases with decreasing mixing and compaction temperatures. Comparatively, a smaller reduction in rut depths was observed by adding the Aspha-Min additive.

The performance properties of bitumen can be improved by using several modifiers, including: polyphosphoric acid (PPA), semi-hot asphalt mixers (WMA) and styrene butadiene rubber (SBR). The present study evaluated the effect of PPA and WMA additives on the rheological behavior of SBR modified bitumen. Modified SBR / PPA and SBR / PPA / WMA bitumen were subjected to rotational viscosity, dynamic shear rheometer, multiple stress and creep recovery (MSCR) and linear slope sweep (LAS) tests. Based on the results of MSCR test at both stress levels, modification of the base bitumen by SBR, PPA and WMA additives improves the permanent deformation performance of the main bitumen. The results of LAS test showed that the use of SBR and WMA additives improves the fatigue life of bitumen. Also, by adding PPA, the fatigue life of SBR modified bitumen is increased. While the fatigue life is longer than the original bitumen. Among warm additives, Sasobit has a better effect on increasing the performance of bitumen.

A critical research area overlooked in previous studies on nano-silica material is the understanding of how its physical characteristics influence its final behavior as a composite when added to the asphalt binder. This study aimed to understand the feasibility of modifying the nanosilica with asphalt binder based on the asphalt binder characteristics. 60/70 penetration grade asphalt cement was prepared by adding (2%, 4% and 6%) of nanosilica by weight of asphalt. Properties of nanosilica material and asphalt cement were first examined. To prepare the modified asphalt binder was heated at 140C, blended by mechanical mixer at a speed of 2000 rpm for different mixing durations (30 to 60) minute. The modified asphalt binder was examined for rheological properties including penetration grade, softening point temperature, penetration index, Brookfield rotational viscosity and ductility test. Results shows that the modified asphalt binder stiffness increases based on rheological properties and sensitivity of temperature decreases with increasing nanosilica percentage. A 4 % nano silica by asphalt weight enhanced the conventional properties of the modified asphalt binder and became proper in hot weather conditions. While ductility of modified asphalt decreases with increasing nano silica percentage, due to stiffness and agglomeration increased. Finally, longer mixing time to more than 60 min had an adverse effect on the ductility property and lead to agglomeration of nanosilica modified asphalt binder.

Rutting is identified and used as the first failure mechanism in most important design conditions of flex- ible pavements. Bitumen can play a decisive role as one of the main materials used in asphalt mixtures, and modifying the properties of bitumen can greatly delay these failures and minimizing them in some cases. In this study, the PG 64-22 bitumen was modified using 2, 4 and 6% weight percentage of nano- silica and the effect of this modifier on reducing rutting failure was evaluated compared to the control sample. The rutting parameters including non-recoverable creep compliance (Jnr ) and the recovered creep (R%) were also evaluated, and then the effect of nano-silica on the improvement of these parameters at high temperatures was evaluated by simulating dynamic loading using Dynamic Shear Rheometer (DSR) and performing the MSCR test at 3 temperatures of 58, 64 and 70 C. After investigating the bitumen behavior in the non-linear viscoelastic state, a significant effect was observed in the rutting parameters. So that, as a result of nano-silica addition, the cumulative strain decreased compared to the control sam- ple and this decrease became more by increasing the modifier percentage, resulting from increasing the creep recovery at the end of each creep cycle. It was also concluded that, the increase in temperature in high and low stresses, has a negative effect on decreasing deformation recovery percent (R%) and the non- recoverable creep compliance (Jnr), both in unmodified and modified bitumen samples, but importantly, the amount of nano-silica effect on the improvement of these parameters was negative, which was dis- cussed in detail in this study. Also, at a certain temperature, increasing the percentage of nano-silica modifier significantly increased R%, and also significantly decreased the Jnr. In the following, the differ- ence of creep recovery in high and low stresses of Rdiff and the difference of the non-recoverable creep compliance in high and low stresses of Jnr diff significantly improved, indicating a reduction in the sensi- tivity of asphalt samples to the applied stress and also a significant increase in resistance of the samples against rutting.

This research aimed to investigate the mechanical and physical properties of Roller Compacted Concrete (RCC) used with Recycled Concrete Aggregate (RCA) as a replacement for natural coarse aggregate. The maximum dry density method was adopted to prepare RCC mixtures with 200 kg/m³ of cement content and coarse natural aggregates in the concrete mixture. Four RCC mixtures were produced from different RCA incorporation ratios (0%, 5%, 15%, and 30%). The compaction test, compressive strength, splitting tensile strength, flexural tensile strength, and modulus of elasticity, porosity, density, and water absorption tests were performed to analyze the mechanical and physical properties of the mixtures. One-way Analysis of Variance (ANOVA) was used to identify the influences of RCA on RCC’s mechanical properties. As RCA increased in mixtures, some mechanical properties were observed to decrease, such as modulus of elasticity, but the same was not observed in the splitting tensile strength. All RCCs displayed compressive strength greater than 15.0 MPa at 28 days, splitting tensile strength above 1.9 MPa, flexural tensile strength above 2.9 MPa, and modulus of elasticity above 19.0 GPa. According to Brazilian standards, the RCA added to RCC could be used for base layers.

In recent years, the use of metal melting slag, one of the waste and unused the metal melting plants, has been considered as an alternative to parts or all rock materials in different layers of metal. The aim of this study was to investigate the use of different percentages of steel slag as a percentage of its coarse rock material in mixing (0 %, 50 % and 100 % of slag in replacement of coarse aggregate material). Also, in order to investigate the effect of polypropylene fiber on roller containing slag, different percentages were used 1 / 0 and 0.3 % respectively. To achieve this goal, 12 mix design schemes were designed for 7 and 28 days of design and for testing each roller - roller plot (6 samples for compressive strength of 7 and 28 days, 3 samples were made for 28 - day compressive strength and 3 samples for special weight and 28 - day water absorption. the results of the experiment show that the pressure resistance of the roller - roller in 28 days by replacing the slag in coarse aggregate was decreased by 50 and 100 per cent, respectively, by about 9 and 21 %, respectively. the addition of fibers by 0.2 % in the compressive strength of specimens, followed by adding 3 / 3 per cent of the compressive strength fibers. also, tensile strength of samples at the age of 28 decreased by replacing the aggregates of convertor slag by 50 and 100 per cent, respectively, by % and 3 % respectively. the addition of fibers by 0.2 % % increased the tensile strength of specimens, and decreased tensile strength by adding 3.5 % of the tensile strength fibers. in the case, the weight of the specimens was increased by 50 % and 11 % by replacing the slag by 50 % and 100 %. while the addition of fibers leads to weight loss of specimens. The results of water absorption showed that all roller - roller samples at 28 days had much water absorption compared to the sample. The absorption of the specimens increases with the increase in the amount of slag convertor substituted by natural materials. For samples with higher values of convertor slag, an increasing trend is found to be found. Mix design specimens containing 100 % of the slag and 0 / 3 % of fibers in 28 days with water absorption of 48.7 % have the highest water absorption of in comparison to control mixture.

In this study, in order to evaluate the performance of neural network, two models of MLP neural network and RBF neural network were used to predict flexural, tensile and compressive strengths. The data used are taken from the results of models fitted to the results of tests performed on roller concrete samples containing different amounts of recycled crumb rubber, fly ash and nanosilica based on compressive, flexural and tensile strength tests. Different types of artificial neural networks have been used to predict the types of concrete strength. In each section, the structure of the neural network used is given along with the table of input information and output results of that network. In each type of neural network, the number of layers and the number of different neurons have been used for modeling. In the tables, the green rows represent the best structure that has been able to predict the strength of concrete well. Also, the best result (lowest error and highest correlation coefficient) has been selected by considering the network performance in simultaneous prediction of resistance types. The results of compressive and tensile strengths are in the same direction and generally in the same direction, but flexural strength usually shows different results.

The aim of designing the roads and airports is to provide a structural composition on the path of motion to transport traffic in a safe, uniform and efficient way and as a result of increasing the traffic load and increasing the load on the axles and procedures, the necessity of design and implementation of stronger asphalt layers is critical to the various failures including moisture sensitivity and rutting phenomenon (as a common phenomenon in the rutting layer failure). In this study, the additives effect of SBS (% 3 and 5 %) and Lucobite (3 % and 5 %)on the performance of the asphalt mixed with the skelton of aggregates (SMA)was investigated. Marshall " s resistance tests, indirect tensile strength, resilient modulus, moisture susceptibility test (using an indirect tensile test and resilient modulus in two dry and wet conditions and Texas boiling test)were conducted to investigate the dynamic and temporal creep of the Hamburg wheel to investigate the behavior of SMA mixtures. The results showed that with the increase of polymeric additives, decrease of penetration rate and softening point were increased. The study of the results of experiments and image processing of boiling water test photographs showed that polymer additives improved the mixed resistance to moisture. Results of dynamic creep test show that by increasing the polymer additives the resistance of specimens is increased. As such, the samples containing 5 % of the SBS had the highest resistance to rutting. Also, the results showed that by increasing the polymer additives the resistance of the samples is increased.

Asphalt pavement recycling has become a common practice across the globe and has been successfully employed in construction of new pavements. While several studies considered utilization of reclaimed asphalt pavement (RAP) aggregates for flexible and rigid pavements, very few attempted its possibility for roller compacted concrete pavements (RCCP). Additionally, studies on the possibility of enhancing the proportion of RAP for RCCP are very scanty. The present study is an attempt to increase the potential of RCCP mixes containing 50% RAP (dust contaminated & stiffened asphalt coated: 50RAP via including various industrial and agricultural wastes such as Silica Fume, Fly ash, and Sugarcane ash as partial replacement of conventional cement. It was observed that the inclusion of the stated admixtures had an insignificant effect on the density of the fresh RCCP mixes, however, increased the moisture demand considerably. In fact, the results firmly indicated the potential of silica fume for RAP-RCCP blends, as, it not only enhanced the physical and mechanical properties, but found to improve the durability of RCCP mixes considerably. Also, utilization of silica fume was found to be economical & environmentally friendly amongst all wastes: with reduced initial construction cost & CO2 emissions by up to 8.4% & 9.7%. As far as the other industrial wastes are concerned, 15% fly ash could also be utilized for producing sustainable RCCP mixes, whereas, higher dosage of fly ash (30%) and sugarcane ash (10 & 15%) may be employed as base layer material of conventional concrete pavements.