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Double bituminous surface treatment (DBST) has been a widely utilized pavement maintenance material due to its capability to restore the surface roughness of existing pavement and provide a layer of protection against weathering, aging, and moisture. However, DBST is highly prone to aggregate loss at an early stage, which is a very common problem experienced by surface treatment. Therefore, to lessen the aggregate loss and prolong the service life of DBST, fiber additive can be incorporated to strengthen the adhesion between the asphalt emulsion and aggregates. This study investigated the performance of glass fiber-reinforced polymer-modified DBST against aggregate loss by conducting laboratory tests using typical DBST as the benchmark of the test results. Four laboratory tests were chosen to represent different loading applications on the surface of the pavement: the bitumen bond strength (BBS) test, the sweep test, the Hamburg wheel-track test (HWT test), and a one-third-scale model mobile load simulator (MMLS3) model. Furthermore, the curing time of the asphalt emulsion was considered in the BBS test and sweep test. Based on all results from the conducted laboratory tests, polymer-modified DBST with glass fiber reinforcement presented an increased resistance to aggregate loss compared with typical DBST. Moreover, it was found that a longer curing time of the asphalt emulsion, whether it was typical or modified, strengthened the surface treatment's resistance to aggregate loss. [ABSTRACT FROM AUTHOR]

Different types of additives are used in asphalt modification to enhance several properties within the asphalt pavement. In various cases, modification is needed by using multiple additives, which is called composite modification. In this study, glass fibre and nano clay were used to modify the asphalt pavement. The amount of these two additives, together with the optimum bitumen content, was determined by the response surface methodology (RSM). Central composite method (CCD) was used for determining the optimum amount of independent variables (nano clay, glass fibre, bitumen content), by evaluating the dependent variables. Marshall mixture design criteria and minimum bitumen content, were the optimal conditions. As a result, the mixture containing 0.2% glass fibre, 3.693% nano clay and 4.096% bitumen content, was predicted to give the most desirable characteristics. Additionally, verification tests were conducted to evaluate the adequacy of the predicted model. The results were within the 95% confidence intervals for all response variables, which demonstrates the validity of the model obtained in the study. Consequently, CCD can be used to obtain design optimisation of asphalt modification with less mixture production for experimental stages. This is a substantial advantage, which supports human safety and environment- friendly practices. [ABSTRACT FROM AUTHOR]

Many researchers use fiber to improve the cracking resistance of asphalt mixtures, but research concerning the effects of fiber on fracture behavior is limited. The fracture behavior of asphalt mixtures with various fiber types (basalt fiber, glass fiber, and polyester fiber) and contents (0.1%, 0.2%, 0.3%, 0.4%, and 0.5%) has been studied using the indirect tensile asphalt cracking test (IDEAL-CT) in conjunction with digital image correlation (DIC) technology. The evaluation indexes used in the test included crack initiation energy (Gif), crack energy (Gf), splitting tensile strength (RT), cracking tolerance index (CTindex), and the real-time tensile strain (Exx) obtained using digital image correlation technology. The results showed that despite the fiber type, the increase of fiber content resulted in first, an increase, and then, a decrease of the cracking resistance of asphalt mixtures, indicating the presence of optimum fiber content—specifically, 0.4%, 0.3%, and 0.3% for basalt fiber, glass fiber, and polyester fiber, respectively. The development of real-time tensile strain, obtained based on digital image correlation technology, could be divided into two stages: slow-growth stage and rapid-expansion stage. In addition, asphalt mixture with basalt fiber presented the best cracking resistance at both the slow-growth and rapid-expansion stages. This research is helpful in understanding the effects of fiber type and content on the fracture behavior of asphalt mixtures and has certain reference significance for the application of fiber in asphalt mixtures. [ABSTRACT FROM AUTHOR]

Copyright of Fly Ash Comprehensive Utilization is the property of Hebei Fly Ash Comprehensive Utilization Magazine Co., Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Fly Ash Comprehensive Utilization is the property of Hebei Fly Ash Comprehensive Utilization Magazine Co., Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study performed an experimental investigation of asphalt concrete with and without fiberglass geogrid reinforcement, using specimens in the laboratory and in situ. A 100kN/m fiberglass geogrid was used. The results showed that with the fiberglass geogrid reinforcement, the flexural strength of the asphalt increased by 24.82%, deformation was significantly reduced, and the elastic modulus did not improve significantly. In addition, using the Hamburg Wheel Tracker test, the fiberglass geogrid reinforced asphalt samples had a 7.41%reduced rutting depth. Finally, two segments in situ were also tested showing that the flexural strength of asphalt concrete increased by 24.27% and the structural strength of the pavement increased by 25.24%. These results show that pavement structures are significantly improved when reinforced with fiberglass geogrid. [ABSTRACT FROM AUTHOR]

Copyright of China Sciencepaper is the property of China Sciencepaper and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Efficient disposal of composite materials recycled from wind turbine blades (WTB) at end-of-life needs to be solved urgently. To investigate the modification effects and mechanism on SBS-modified asphalt of the recycled glass fiber (GF) from WTB, GF-WTB/SBS composite-modified asphalt was prepared. Dynamic shear rheometer (DSR) and bending beam rheometer (BBR) were adopted to evaluate its performance. FTIR, SEM, EDS, and AFM methods were used to assess coupling agent pretreatment effects on GF-WTB and observe the modification mechanism. The macroscopic tests show that reasonable addition of GF-WTB effectively raises the high-temperature performance and low-temperature crack resistance evaluation index k-value of SBS-modified asphalt, and the optimal content is 2 wt% GF-WTB with 4 wt% SBS. FTIR, SEM, and EDS tests show GF-WTB can be successfully grafted by UP152 coupling agent and show that adhesion of the GF-WTB to the SBS-modified asphalt can be improved. AFM observation shows SBS and GF-WTB have good compatibility, improving the asphalt elasticity and toughness. This study provides a feasible solution for environmentally friendly regeneration of the composite materials from WTB and contributes to the development of the secondary modifier of SBS-modified asphalt. [ABSTRACT FROM AUTHOR]

Glass fiber reinforced polymer (GFRP) is the main composite material used in wind turbine blades. In recent years, zero-carbon energy sources such as wind power have been widely used to reduce carbon emissions, resulting in a large amount of waste GFRP, and causing serious environmental problems. To explore efficient ways to recycle waste GFRP, this study explores the impact of adding GFRP powder (nominal maximum particle size ≤ 0.075 mm) on the high and low temperature properties of asphalt mastic. Samples of GFRP asphalt mastics were prepared with filler-asphalt mass ratios of 0.01:1, 0.1:1, 0.8:1, and 1:1, as well as two control samples of limestone filler asphalt mastics with filler-asphalt mass ratios of 0.8:1 and 1:1. The study analyzed the effect of GFRP on the asphalt mastic's performance using temperature sweep, MSCR, and BBR tests. Results showed that the presence of GFRP improved the high-temperature resistance and recovery of asphalt mastic but led to decreased low-temperature crack resistance. The results suggest that GFRP has the potential to be used as a filler in asphalt mastic, with a recommended filler-asphalt mass ratio range of less than 0.8:1 for optimal low-temperature performance. However, further research is necessary to determine the optimal content of GFRP in asphalt mastic and to study its impact on other road performance metrics. [ABSTRACT FROM AUTHOR]

Environmentally friendly porous asphalt mixtures have poor tensile strength performance and durability due to their porous structure. This results in their service life typically being less than ten years. Reinforcement with fibers can be a possible solution to structural weaknesses in porous asphalt road surfaces. Fibers have been proven to be an effective additive in improving the mechanical performance of asphalt mixes, but little attention has been paid to porous asphalt mixes. This study investigates the effect of four different fibers; (a) polypropylene fiber, (b) glass fiber, (c) basalt fiber, and (d) crumb rubber, on the functional and mechanical performance of porous asphalt mixtures. Fibers were used in four different percentages (0.2, 0.4, 0.6 and 0.8%) according to the mix aggregate weight. The experimental test plan includes the characterization of air voids for permeability, Cantabro particle loss, indirect tensile strength, and moisture sensitivity. Type-3 gradation (in Turkish Highways Technical Specification) was chosen as the mixture gradation. Mixture specimens were prepared using a Marshall compactor in 6.0 and 6.5% polymer-modified bitumen. Test results show that void and permeability generally decrease with increasing fiber content, except for polypropylene fiber. Cantabro particle loss was significantly reduced for all fibers at 6.5% bitumen compared to 6.0%. Minimum wear loss value was obtained in 0.2% basalt fiber. Indirect Tensile Strength (ITS) improved significantly for all fibers. The ITS of 0.2% basalt fiber was enhanced by 124% compared to the control specimens. The optimum fiber contents were determined as 0.2% for basalt fiber and 0.4% for glass fiber. [ABSTRACT FROM AUTHOR]

Pavement design is a long-term structural analysis that is required to distribute traffic loads throughout all road levels. To construct roads for rising traffic volumes while preserving natural resources and materials, a better knowledge of road paving materials is required. The current study focused on the prediction of Marshall stability of asphalt mixes constituted of glass, carbon, and glass-carbon combination fibers to exploit the best potential of the hybrid asphalt mix by applying five machine learning models, i.e., artificial neural networks, Gaussian processes, M5P, random tree, and multiple linear regression model and further determined the optimum model suitable for prediction of the Marshall stability in hybrid asphalt mixes. It was equally important to determine the suitability of each mix for flexible pavements. Five types of asphalt mixes, i.e., glass fiber asphalt mix, carbon fiber asphalt mix, and three modified asphalt mixes of glass-carbon fiber combination in the proportions of 75:25, 50:50, and 25:75 were utilized in the investigation. To measure the efficiency of the applied models, five statistical indices, i.e., coefficient of correlation, mean absolute error, root mean square error, relative absolute error, and root relative squared error were used in machine learning models. The results indicated that the artificial neural network outperformed other models in predicting the Marshall stability of modified asphalt mix with a higher value of the coefficient of correlation (0.8392), R2 (0.7042), a lower mean absolute error value (1.4996), and root mean square error value (1.8315) in the testing stage with small error band and provided the best optimal fit. Results of the feature importance analysis showed that the first five input variables, i.e., carbon fiber diameter, bitumen content, hybrid asphalt mix of glass-carbon fiber at 75:25 percent, carbon fiber content, and hybrid asphalt mix of glass-carbon fiber at 50:50 percent, are highly sensitive parameters which influence the Marshall strength of the modified asphalt mixes to a greater extent. [ABSTRACT FROM AUTHOR]

The Stability of asphalt concrete is necessary in the design of flexible pavement. Many methods and additives are being successfully used to enhance the crack resistance of asphalt. Fiber reinforcement is a constructive approach to improve the performance of asphalt pavement. In this investigation, Marshall Stability of asphalt concrete reinforced with glass fiber is predicted using soft computing techniques such as Artificial Neural Network (ANN), Random Forest (RF), Random Tree (RT) and Adaptive Neuro-Fuzzy Inference System (ANFIS). For this, data set was collected from experiments and various creditable research papers. The performances of applied models were evaluated using five statistical indices such as coefficient of correlation (CC), Root Mean Square Error (RMSE), Willmott's index (WI), Nash-Sutcliffe coefficient (NSE) and Mean absolute error (MAE). Performance of Trapezoidal membership function-based ANFIS model is outperforming among all applied models with CC value as 0.8347, RMSE value as 2.7254, WI value as 0.7310, NSE value as 0.6951 and MAE value as 1.8756. The sensitivity analysis was also carried out using best performing model (Trapezoidal membership function- based ANFIS) with this data set, which suggest that Bitumen Grade (VG) has a major influence in predicting the Marshall Stability of asphalt concrete. This study suggests that the glass fiber (%) and Bitumen content (%) has also significant factor for the predicting the Marshall Stability of single-factor ANOVA outcomes suggest that there is no significant variation among actual and predicted values using various applied models. [ABSTRACT FROM AUTHOR]

Nowadays, due to the increase in the amount of traffic and the number of axles, the use of additives in asphalt concrete has become common. In recent decades, one of the goals of engineers in asphalt technology has been to increase the bearing capacity and improve the tensile strength of asphalt mixtures. One of these effective additives in this matter is fiber. Fibers mainly contribute to the reinforcement of asphalt mixtures. Accordingly, in this research, the properties of asphalt mixtures reinforced with 5-component fibers and glass fibers have been investigated. 5-component fibers are added in 0.05, 0.075, and 0.01% of the weight of stone materials, and glass fibers are added in 0.1, 0.2, and 0.3% of the weight of stone materials in asphalt mixtures and finally, based on performance characteristics including Marshall resistance, indirect tension, moisture sensitivity, dynamic creep, and resilient modulus are the most optimal among the above percentages. According to the results of this research, 5-component fibers have the best results in many of the mentioned characteristics at 0.075 percent and glass fibers at 0.2 percent. [ABSTRACT FROM AUTHOR]

In order to improve the quality of the porous asphalt pavement in seasonal freezing areas and reduce the freeze-thaw damage of the pavement, the modified porous asphalt mixture with glass fiber, diatomite and old asphalt pavement materials are employed to improve the performance. The changes in compressive strength, porosity, and strain of porous asphalt mixtures with different material contents after freeze-thaw cycles are analyzed by considering the influence of different materials and different material contents on the water stability of porous asphalt mixtures. Based on the theory of damage mechanics, the compressive strength is used as an index to represent damage variables, and the evolution of freeze-thaw damage of modified porous asphalt mixtures is also studied. Based on the CT non-destructive testing and digital image processing technology, the changes in the number of air voids and air void area of the glass fiber porous asphalt mixture before and after freezing-thawing are analyzed. The test results show that the compressive strength of the mixture decreases with the increase of the number of freeze-thaw cycles, and the void ratio and strain show an increasing trend. Four porous asphalt mixtures with 0.7% glass fiber content, 15% old asphalt pavement material content, 25% diatomite content and 15% old asphalt pavement material and 20% diatomite content present the best water stability. The modification effect of glass fiber is the best. Mixing glass fiber, 15% diatomite and 15% old asphalt pavement material may reduce the freeze-thaw damage of porous asphalt mixtures. However the recycled porous asphalt mixtures containing diatomite have more serious damage and have higher strength in the early stage of damage, which are more suitable for short-term frozen soil areas. Compared with recycled porous asphalt mixtures containing diatomite, the porous asphalt mixture containing glass fiber, recycled porous asphalt mixture and porous asphalt mixture containing di-atomite have a longer rapid damage period, a shorter damage stability period and a shorter damage evolving period. The number of air voids in the sample increases and the average single air void area decreases with a lower glass fiber content, while the sample with a higher glass fiber content has the opposite effect. [ABSTRACT FROM AUTHOR]

Due to environmental issues and rising costs of construction materials, there is an increasing desire to use reclaimed asphalt pavement (RAP) material in road construction. However, using too much of this material may lead to impairment of fundamental properties of asphalt mix. Glass fibre material is a well-known modifier and could be used to compensate possible downgrade of properties. Research articles and theoretical material have shown that adding too much fibre glass reinforcement could cause damage to asphalt mixture. Therefore, in this research, reference mixture has been compared to three projected AC 11 surface mixtures with different amount of fibre glass. The same has been done to HMAC mixtures, but in this case, there is crumb rubber used as mixture modifier. Experimental part has shown that using fibre glass in asphalt mixtures for both construction layers may have positive influence on fundamental parameters of HMAC and AC asphalt mixes, which can be a good solvation for using waste glass fibre in road construction. [ABSTRACT FROM AUTHOR]

Using high contents of the RAP material in newly produced asphalt mixtures leads to a reduction in the crack resistance of the mixtures. This shortcoming can be compensated using some methods such as polymer modification, rejuvenation, fibre-reinforcement, etc. In this paper, the effect of Cyclogen as a rejuvenator and glass fibre was investigated on the cracking behaviour of recycled asphalt mixtures. For this aim, the fracture energy and critical value of J integral (Jc)of semi-circular bending (SCB) asphalt specimens in terms of RAP content, Fibre content and testing temperature were investigated in this study and the results were used to develop an experimental model to predict the crack resistance of asphalt mixtures in terms of temperature and fibre and RAP content using the artificial neural network (ANN) and the multiple regression methods. The results indicated that the fracture energy and Jc valueof asphalt mixtures declined by increasing the RAP contentat intermediate temperatures. However, the reduction in fracture energy and Jc valuecould be compensated using the fibres. Both investigated models were appropriate for predicting the cracking behaviour of fibre-reinforced recycled asphalt mixtures. Nevertheless, the level of correlation was much higher for the ANN approach than the multiple regression model. [ABSTRACT FROM AUTHOR]

To delay the expansion of reflective cracks on semi-rigid base asphalt pavements and strengthen the cracking resistance of asphalt rubber stress-absorbing membrane interlayers, the bonding and fracture performances as well as cracking resistance of a fiber-reinforced asphalt rubber stress-absorbing membrane interlayer (FAR-SAMI), rubber asphalt stress-absorbing membrane interlayer (AR-SAMI), and SBS-modified asphalt stress-absorbing membrane interlayer (AS-SAMI) were studied. In addition, the resistance to reflective cracking for FAR-SAMI was evaluated by finite element (FE) analysis. The results show that FAR-SAMI exhibits appropriate bonding performance at 15 and 40 ° C. The addition of glass fiber increases the toughness of the composite specimens and the fracture energy of FAR-SAMI increases by 23% compared with AR-SAMI. Furthermore, FAR-SAMI is effective in restraining the development of reflection cracks and prolonging the fatigue life. FE analysis also shows that FAR-SAMI can significantly reduce the stress concentration phenomenon in the crack. Therefore, fiber-reinforced asphalt rubber was found to be suitable as a SAMI to prevent and control reflective cracking. [ABSTRACT FROM AUTHOR]

Asphalt concrete is the prevailing material used for road surface construction. Its adequate characteristics in providing stability, durability and driving safety are controlled by complex interactions between its components. Thus, it is important to estimate the sensitivity of asphalt concrete mechanical properties as a function of its volumetrics. For this study, different combinations between asphalt content (3.5, 5 and 7.5%) and porosity values (above 4%) were used in order to disassociate these properties. The influence of mixing in fiberglass (0.5%) was also analyzed. It was found that porosity is significantly more relevant than the asphalt content in the prediction of tensile strength and resilient modulus of fiber-free asphalt concretes. In fiber-reinforced mixtures, the mechanical properties are improved by increasing the asphalt content, which suggests a better bonding between fibers and aggregates. For both cases, decreasing porosity is beneficial. By grouping both sets of results, it was possible to create a unique theoretical curve for both the tensile strength (q t) and the resilient modulus (RM). The RM/q t ratio was 5800 for the fiber-free group, and 3900 for the fiber-reinforced group - suggesting a better fatigue life indicator for asphalt concretes when fibers are added. • Assessing the effect of porosities and amounts of asphalt on fiberglass-reinforced asphalt concrete's mechanical properties. • The mechanical response of the materials was correlated to the porosity/asphalt cement index through power functions. • Fiberglass additions to asphalt concrete were shown to affect tensile strength more so than the resilient modulus. [ABSTRACT FROM AUTHOR]

Micromechanical behavior of the interface between fiber and asphalt is a crucial factor in the performance of fiber reinforced asphalt concrete, and a thorough understanding of this behavior is essential for the design and optimization of these materials. To evaluate the micromechanical behavior of the interface, an innovative single fiber pullout test platform was designed, and the experimental parameter conditions were systematically studied. Three types of fibers including basalt fiber (BF), glass fiber (GF) and polyester fiber (PF) were adopted, and the pullout test was performed at 60 ℃, 25 ℃ and −10 ℃, respectively, where the micromechanical behavior at the interface under different experimental conditions was obtained. The results showed that the recommended loading rate of the fiber pullout test is 1–3 mm/min, and the measurement of variability is satisfactory. The single fiber pullout behavior was observed and the load-displacement curve was recorded real-time. Three failure modes (fiber pullout, fiber fracture and matrix failure) at the interface between the single fiber and asphalt mastic were observed. Furthermore, a bond-slip model which can accurately characterize the bonding-debonding behavior of the interface between the single fiber and asphalt mastic was established. It was found from the study that micromechanical behavior of the interface between the single fiber and asphalt mastic is influenced by the type of fiber and temperature, the peak load and displacement are significantly different. These findings presented in this study can play a significant role in revealing the reinforcement mechanism of fiber and providing a guidance for the efficient application and development of fiber reinforced asphalt mixture. • An innovative single fiber pullout test platform was self-designed. • The micromechanical behavior of fiber- asphalt mastic interface was investigated. • Three failure modes of the interface including fiber pullout, fiber fracture and matrix failure were observed in real time. • Bond-slip model of the interface was established based on Popovics equation. • Micromechanical behavior of the interface was greatly affected by fiber type and experimental temperature. [ABSTRACT FROM AUTHOR]

This study is aimed at investigating short- and long-term aged properties of glass fibre (GF)-reinforced asphalt mixtures using indirect tensile strength (ITS) and associated fracture energy, moisture susceptibility, creep compliance, resilient modulus, and indirect tension continuous and discontinuous (IDT) fatigue tests. Also, to portray the influence of fibre reinforcement at micro level, a micromechanical finite element model (MFEM) was built utilising representative volume element (RVE) to consider the effect of fibre dose, length, and dispersion (fully aligned or random) on the mechanical characteristics (or stress-strain curve) of the composite under unidirectional strain perturbation. Based on the study results, for the same binder, compared to shorter fibre (i.e. 6-mm length), the application of 12-mm GF to the mixtures showed unnoticeable change in the short- and long-term properties of the reinforced mixtures. On the whole, the GF can impart positive characteristics to the asphalt mixture such as increase strength, resistance to rutting, less susceptibility to moisture damage, retard fatigue cracking, enhance healing capability, and combat adverse aging changes. Unlike the effect of fibre length, the numerical model proved that the orientation and concentration of GF showed noticeable influence on the mechanical response of the composite. Overall, using the GF in asphalt mixtures can help produce durable bituminous pavements. Although the present study investigated the GF-reinforced bituminous materials from performance stand point, one can speculate that building GF-reinforced pavements is more costly initially compared to unreinforced pavements however the benefits may be received over time by extending service life and saving the maintenance cost of the bituminous pavement. [ABSTRACT FROM AUTHOR]

Moisture damage and low-temperature cracking are common distresses experienced by road pavement. Different types of modifiers, such as fibers, can be used to improve the quality of asphalt pavements. In this paper, lignin and glass fiber were selected as additives to enhance the water- and low-temperature stability of the asphalt mixtures. The main objective of this study was to evaluate the composite effects of adding lignin fiber and glass fiber to a bituminous mix using experimental methods. The Marshall immersion, freeze–thaw splitting, and three-point bending tests were applied to evaluate the efficiency of lignin fiber (and/or) glass fiber modified asphalt mixes with regard to moisture damage and low temperature. Four kinds of asphalt mixtures, namely, the control asphalt mix (C), lignin fiber modified asphalt mix (L), glass fiber modified asphalt mix (G), and a composite of lignin fiber and glass fiber modified asphalt mix (LG) were evaluated. The experimental results showed that with the addition of 0.30% lignin fiber and 0.30% glass fiber the water stability, low-temperature stability, and quality of bituminous mix were improved significantly. With lignin fiber, the asphalt mixtures showed better resistance to thermal cracking, while glass fiber resulted in greater moisture susceptibility. The composite admixture was more effective than either lignin or glass fiber in modifying the asphalt performance. This clarifies the great beneficial effect of using the composite mixture in the asphalt mixtures industry. [ABSTRACT FROM AUTHOR]

Copyright of China Sciencepaper is the property of China Sciencepaper and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Using of Reclaimed Asphalt Pavement (RAP) has been become indispensable in most of the world nations as for its many benefits as significant cost savings and provide environmental benefits. Many factors such as virgin materials, binder content, availability of RAP, viscosity of binder and extent of deterioration had important role in effecting on Optimum percentage of RAP. In this study, effect of using RAP on the asphalt mixture properties and the its optimum ratio was determined to achieve the objective of the study. The glass fiber (GS) was used as additives to improve the asphalt mixture. It has been observed from the previous researches that the optimum percentage of reclaimed asphalt use is not determiner and is disagreed from project to project. So, different percentages of RAP was (25%, 50%, 75%, 100%) by weight of aggregate were added as well as using the additive GS at optimum bitumen content. The study is revealed that untreated 100% RAP materials are not good as a bituminous mix. and was showed that mix prepared with 25% RAP gave nearly the same physical and strength parameters as virgin bituminous mix. From results of study, the use of RAP until (%50) as a maximum percentage in unmodified asphalt mixture course sustained good results. To achieve better performance, the percentage of 25% RAP was used with percentage of 0.26% GS. This mix achieved the specification requirements and ensured the degree of better performance for paving. The economical evaluation of using percentage of 25% RAP with percentage of 0.26% GS was also studied. The results indicated that, about 21% of the cost was saved. [ABSTRACT FROM AUTHOR]

Carbon-based supercapacitor textiles with superior electrochemical performance and mechanical flexibility have attracted considerable attention as an important category of smart wearable textiles. However, the time-consuming fabrication process and high production cost limit their practical application. Herein, inexpensive composite electrodes composed of commercial activated carbon (AC), carbonized asphalt (CA) derived from recycled asphalt pavement and fiberglass cloth (FGC) were prepared via a facile dip-coating method, followed by one-step carbonization process. The effects of carbonization temperature and the mass ratio of AC to asphalt on the structure and electrochemical performance of the AC/CA/FGC electrodes have been investigated. The AC/CA/FGC electrode prepared at optimum conditions has a high specific capacitance of 499.3 mF cm-2 at 1 mA cm-2. The asfabricated all-solid-state symmetric AC/CA/FGC supercapacitor exhibits excellent specific capacitance of 85.4 mF cm-2, power density of 1.23 mW cm-2, energy density of 7.60 µWh cm-2, 87% capacitance retention after 10000 charge/discharge cycles and outstanding mechanical flexibility. The desired overall performance, scalable manufacturing process and relatively low production cost demonstrate the potential of AC/CA/FGC supercapacitor textile for the application in high-performance energy storage textiles. [ABSTRACT FROM AUTHOR]

[Display omitted] • The current study evaluates the fracture energy of HMA when basalt and glass fibers are used. • The fracture energy of the mixtures was determined via the SCB test method. • The effect of the basalt and glass fibers on the fracture energy of HMA was compared. • The maximum fracture energy was attained from the groups with a 0.50% basalt fiber rate. This paper has focused on the effect of basalt and glass fibers in HMA in terms of crack formation and damage mechanisms. The experimental study was carried out under two stages; i) defining optimum fiber lengths and rates based on Marshall Stability performances using three different fiber lengths (4 mm, 12.5 mm, 22.5 mm) and three different fiber rates (0.75%, 1.00% and 1.5% by weight), ii) examining of fracture tests by using the optimum fiber values (4 mm fiber length and 0.50%, 0.75%, 1.00% fiber content by weight) obtained from the first stage. Fracture energy characteristics of HMA mixtures were examined via Semi-Circular Bending (SCB) test. A total of 24 SCB test specimens from 6 different series, B-0.50, B-0.75, B-1.00, G-0.50, G-0.75, and G-1.00, were used in the experiments. Experimental results were discussed based on some basic physical properties, fracture energy (Gf), dissipated energy (DE), flexibility index (FI), and crack resistance index (CRI) values of HMA mixtures. When 0.50% basalt fiber is utilized in asphalt mixtures, the maximum peak load and Gf value are achieved. Moreover, using 1.00% basalt and 0.75% glass fiber in asphalt mixtures yielded the highest values of FI and CRI, respectively. Nevertheless, when 1.00% glass and 0.75% basalt fiber were added to asphalt mixtures, the minimum values of FI and CRI were obtained, respectively. [ABSTRACT FROM AUTHOR]

Waste Fiber-Reinforced Polymer (FRP) composites have become an environmental issue in China, Europe, and the United States. However, recycling waste FRP composites poses sustainability challenges in the long term because their predominantly cross-linked structure (thermoset matrices coating) typically cannot be re-used or re-processed. Here, for the first time, we studied the merits of introducing recycled glass fibers (rGF) to bitumen to enhance bitumen's durability as measured by resistance to aging and resistance to moisture damage. We compared the reinforcement efficacy of recycled glass fibers (rGF) with recycled glass fibers after the polymer coating was removed (rGFWP) and with virgin glass fibers (vGF). After aging, compared to the bitumen with rGFWP, the bitumen containing rGF showed enhanced resistance to oxidative aging, as evidenced by lower values of two indexes of chemical aging (a 64.5% lower carbonyl index and a 94.5% lower sulfoxide index), a 47.10% lower increase in the ratio of large molecular size, and a 61.41% lower rheological aging index. Moreover, bitumen containing recycled glass fiber demonstrated noticeably improved resistance to moisture damage as compared to base bitumen, particularly for rGFWP, as demonstrated by energy ratio (ER) values that were 478% higher. The resistance to moisture damage of bitumen containing rGF was also significant improved, as evidenced by a 72.78% increase in surface energy, the better MISTI value (the least variation from a value of one), and a 213% higher ER value compared to base bitumen. This indicates that recycled glass fibers have positive effects on the durability of bitumen composites. The outstanding durability of bitumen with recycled glass fibers highlights the feasibility of adding recycled glass fibers to bitumen as a practical application that provides an economic and environmentally friendly solution for waste glass fibers. Use of recycled glass fiber in bitumen enhance its durability and delays aging. [Display omitted] [ABSTRACT FROM AUTHOR]

• The rutting performance and resilient modulus improved by increasing the amount polyolefin-glass fiber in HMA. • Polyolefin-glass fiber is beneficial for enhancing moisture resistance of HMA. • 12% of polyolefin-glass fiber is recommended to withstand fatigue and cracking of HMA. • 18% of polyolefin-glass fiber is recommended when rutting is the only issue. The synthetic compound fibers have been introduced as a modifier to improve rutting, fatigue and low-temperature behavior of asphalt mixtures. In this research, the combination of Polyolefin powders and glass fibers was used by different percentages as an additive in hot mix asphalt, and the performance properties of modified and unmodified asphalt mixtures were evaluated using resilient modulus, modified Lottman, water boiling, dynamic creep, indirect tensile fatigue and SCB fracture tests. The results indicated that using up to 0.12% of the synthetic fiber by weight of total mixture enhanced the performance of the mixture in all studied aspects as the Polyolefin component helped the elastic behavior and rutting resistance, and the high strength glass fibers improved the tensile strength, fatigue and crack resistance. However, increasing the amount of polyolefin-glass fiber to 0.18% had some adverse effect on resilient modulus, fatigue, fracture, and tensile resistance of the mixtures. [ABSTRACT FROM AUTHOR]

• The sample which has the largest permeability, had the minimum value of draindown. • The effect of glass fiber in reducing the permeability is far greater than that of the basalt. • The tensile strength of asphalt mixtures increases by adding fiber. • The effect of nano-silica in reducing abrasion and reduction of sensitivity to oxidation is considerable. Open-graded friction course (OGFC) is a mixture having gap graded aggregate which is used in pavement surfacing. Asphalt mixtures were modified by Nano silica, polymer, basalt fiber and glass fiber. A draindown test, Cantabro test, permeability test and an indirect tensile strength test and moisture susceptibility were used to evaluate the performance of OGFC mixtures. Test results revealed optimum compounds for 0.2% basalt fiber with 2% nano-silica and 4.5% Styrene-Butadiene Styrene (SBS) Polymer. The minimum air voids content of fiber-reinforced OGFC mixtures modified with nanomaterial should be 13% for 6% bitumen. The results showed the effect of nano-silica in reducing abrasion and reduction of sensitivity to oxidation is considerable and the effect of basalt fiber per 0.2% in the asphalt mixture to be greater than that of glass fiber in reducing the draindown phenomenon; and for controlling the level of draindown phenomenon, nano-silica compound should also be used with basalt fiber. It was also found that although the use of basalt fiber is more effective in decreasing draindown in comparison with glass fiber, the effect of glass fiber in reducing the permeability of the asphalt mixture is far greater than basalt fiber. [ABSTRACT FROM AUTHOR]

Highlights • We reviewed the asphalt mixes modified with lignin fiber and glass fiber. • Studied of rutting, water damage, thermal and fatigue cracking in asphalt mixes. • Lignin fiber improves the resistance to low temperature cracking in asphalt mixes. • Glass fiber improves the high temperature performance in asphalt mixes. • Both fibers improve fatigue performance and water stability in asphalt mixes. Abstract Low temperature thermal cracking, rutting, moisture damage and fatigue cracking are popular damages that appear in the asphalt mixture. These problems occur mainly because of the growth in the number of heavy load vehicles, design and construction errors and environmental condition that reduce the quality, performance and the service life of the pavement. Several previous studies showed that using additives like fibers to modify asphalt mixtures could enhance the efficiency and boost the quality and service life of the pavement. This paper presents a review of the role of lignin and glass fiber as a modifier in bituminous mixes. To evaluate some main mixture properties, some tests such as the low temperature bending, indirect tensile strength, the wheel loading tracking, Hamburg wheel tracking, Marshall immersion, freezing-thaw splitting, third-point bending fatigue and indirect tensile fatigue are applied to analyze rutting, low temperature cracking resistance, moisture damage resistance and fatigue resistance of asphalt mixture modified with lignin or glass fiber. Results denoted that the quality of asphalt mixture enhanced significantly by adding lignin fiber or glass fiber. Previous researches demonstrated an obvious improvement in low temperature performance in the pavement when adding 0.2–0.4% lignin fiber of asphalt mixtures, with a limited improvement of high temperature performance. On the contrary, the asphalt mixtures modified with 0.2–0.6% glass fiber of asphalt mixtures significantly improved the resistance of high temperature. So it is hard to improve all the performances of the mixture by using only a single admixture at the same time. Thus, a new way of modifying asphalt mixture that is called double-mixture technology or composite modification, which is able to enhance the overall properties of asphalt mixture. [ABSTRACT FROM AUTHOR]

The performance and the fundamental weaknesses of the asphalt mix have made the researchers think about modifying the technical properties of the asphalt mix by using the appropriate additives. The fiber spreads through the asphalt mix and prevents the development of the micro-cracks by producing a more coherent mix and increasing its durability. The present study, for the first time, has used two additives, lignin and glass fiber (6 and 12 mm in length), to improve the performance of asphalt mix. Mixing was done in a way that lignin and glass fiber were added to the bitumen and aggregates, respectively. According to the results, the length of the used glass fiber has a significant effect on the Marshall Resistance and asphalt mix performance so that glass fiber in 6 mm length has reduced the Marshall strength and glass fiber in 12 mm length has increased the Marshall strength. Moreover, the results of resilient modulus indicate that having a stable percentage of fiber and an increasing lignin percentage, it behaves differently at two temperatures of 15 and 25 ∘ C, confirming once again the fact that the length of fiber plays a decisive role on the result of resilient modulus. [ABSTRACT FROM AUTHOR]

Open-Graded Friction Course mixture (OGFC) has a gap-graded aggregate that results in highly air voids. This structure provides higher permeability by allowing water to flow through it. Although these mixtures have good drainage properties, they exhibit poor strength with a short life span. Because of their poor performance, there is a lack to be used in pavement application. Attempts had made to increase mixture performance; one of these methods is by using fibers or polymers. The objective of the current study is to determine if modified OGFC mixes with different polymers and fibers have comparable performance. Polymers and fibers were used in OGFC mixes to evaluate their performance. Steel fiber, glass fibers, Polyvinyl chloride (PVC) and Phenol resin were investigated in this study. The modified mixtures were tested by indirect tensile strength, Marshall and permanent deformation tests. Results showed that fibers decrease rutting by 19% and they have more effective than polymers that decrease rutting by 7%, and glass fiber was found to be more effective with a 24% reduction in permanent deformation than other additives to enhance performance. [ABSTRACT FROM AUTHOR]

Highlights • Evaluated impacts of geogrid on the HMA-overlays interlayer bond strength. • Unreinforced, polyester (FA) and fiberglass (FG) based interlayers were assessed. • The unreinforced HMA samples exhibited the highest bond strength followed by FA. • The HMA samples with FG based geogrids exhibited the least bond strength. • Geogrid type, size of mesh and strands both impacted the interlayer bond strength. Abstract With the increasing use of geogrid reinforcements to mitigate reflective cracking in hot-mix asphalt (HMA) overlays, interlayer (interface) bonding has become an even more critical aspect of HMA placement/construction to mitigate delamination and debonding of the HMA overlay. To comparatively evaluate the interlayer bond strength due to the effects of the geogrid reinforcements, the shear bond strength test was conducted in this laboratory study, using unreinforced control HMA samples as the reference datum. Cylindrical HMA samples (150 mm diameter) gyratory compacted in two 75-mm lift thicknesses, with the geogrid reinforcement in-between the two lifts, were used for testing at room temperature under a monotonically shear loading rate of 5 mm/min. Emulsified asphalt was used as the interlayer tack coat and six different geogrid materials, which are polyester-based (FA) and fiberglass-based (FG), were comparatively evaluated. As theoretically expected, the control (unreinforced) HMA samples exhibited superiority followed closely by samples reinforced with polyester-based geogrids. Although comparable to the values reported in the literature, HMA samples reinforced with fiberglass-based geogrids performed the poorest with the lowest interlayer bond strengths – that is the polyester-based outperformed the fiberglass-based geogrids. Overall, the interlayer bond strength exhibited a general decreasing trend with a decrease in the geogrid mesh size (open area), increase in the geogrid strand thickness, and material grade. Thus, in as much as reflective crack mitigation is structurally desired, due diligence must be cautiously exercised when selecting the geogrid type/grade for use in HMA reinforcement to ensure sufficient interlayer bonding and minimize any potential delamination/debonding problems in service. [ABSTRACT FROM AUTHOR]

• Effect of RAP and glass fiber on fracture behaviors of UTFC were investigated. • The size-independent fracture energy was obtained considering the tail part of the load–displacement curve. • Two new parameters, cracking resistance index and balanced cracking index, were adopted to characterize the fracture performance. Ultra-thin friction course (UTFC) presents excellent performance in preventative maintenance of asphalt pavement. UTFC could be also used as the wearing course of newly constructed pavements. This study investigated the effects of reclaimed asphalt pavement (RAP) and glass fiber on the fracture behaviors of UTFC at the low and intermediate temperatures. At the low temperature (-10℃), fracture energy, stress intensity factor and cracking resistance index (CRI) were obtained to present the fracture behaviors of three types of UTFC mixtures. At the intermediate temperature (25℃), the size-independent fracture energy considering the tail part of the load–displacement curves were obtained. Besides, J-integral, cracking resistance index (CRI) and balanced cracking index (BCI) were obtained to characterize the intermediate fracture performance. Results indicated that at −10 ℃, the incorporation of RAP weakened the fracture resistance of UTFC; while the addition of glass fiber could counteract the adverse effect of RAP. Besides, CRI value of UTFC with glass fiber was the largest, indicating the superior fracture resistance at the low temperature. At 25 ℃, UTFC presented the best cracking resistance in terms of fracture energy, J-integral, CRI values and BCI values, indicating the incorporation of RAP could deteriorate the fracture resistance at the intermediate temperature. When both RAP and glass fiber were added in UTFC, the fracture performance was deteriorated furtherly, which may be possibly caused by the non-uniform distribution of fiber. On the other hand, the bonding strength between fiber and asphalt could be mitigated when temperature increased from −10 ℃ to 25 ℃. The size-independent fracture energy of UTFC was the largest, indicating the superior fracture resistance, followed by UTFC-50% RAP-F and UTFC. It was also reported that the incorporation of fiber improved the ability to tolerate deformation. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to investigate the compound effects of diatomite and glass fiber on asphalt mixture. The diatomite and glass fiber compound modified asphalt mixture (DGFMAM) was prepared in laboratory. Performances of DGFMAM were investigated by experimental method. Wheel tracking test, low temperature indirect tensile test, indirect tensile fatigue test (ITFT) and indirect tensile stiffness modulus test (ITSM) were carried out. The statistical analysis of variance (ANOVA) method and statistical regression method were used to evaluate the effects of diatomite and glass fiber on properties of asphalt mixture. Results indicate that diatomite and glass fiber improve the rutting resistance and fatigue properties of control asphalt mixture. Diatomite has a significant effect on the stiffness modulus of asphalt mixture. Disadvantage of diatomite on low temperature deformation property of asphalt mixture is solved by glass fiber. DGFMAM has better travelling performances than the control mixture. It will provide a reference for the design of compound modified asphalt mixture. [ABSTRACT FROM AUTHOR]

This study presents an experimental overview of thermoplastic polymer-coated glass fibre and scrap-reinforced hot-mix asphalt (HMA) mixtures. The toughening effects of the reinforced HMA mixtures were characterised using indirect tensile and Hamburg wheel-tracking tests. The indirect tensile loading tests were used to calculate the relative indirect tensile strengths of samples and to compare their moisture susceptibilities. The fibre’s relative contributions to increasing the indirect tensile strength and the resistance to rutting are quantified by comparing the maximum indirect peak tensile stress and tensile strength ratio (TSR). The indirect tensile strength and TSR of the fibrous mixtures are nearly two times higher than those of the plain mixtures, demonstrating the lower moisture susceptibility and superior field performance of the fibrous asphalt mixture. Accelerated rutting tests using the Hamburg wheel test setup for the fibrous mixtures caused at least three times more loading passes to be required to reach the rut-depth criteria compared to the number of loading passes required for the plain mixtures. [ABSTRACT FROM AUTHOR]

Fiber Reinforced Polymer (FRP), especially glass fiber reinforced polymer (GFRP), has been widely used in construction, navigation, transportation, and chemical engineering due to its excellent physical and mechanical properties. As a result, a great amount of waste GFRP is produced which leads to serious environmental pollution, and an efficient treatment method of waste GFRP is urgently needed. In this research, the waste epoxy-based GFRP composite powder was recycled as an mineral filler alternative for the fabrication of asphalt mastics, and the properties of the GFRP powder asphalt mastics were investigated. The results show that the waste GFRP powder has a greater specific surface area and lower density than limestone fillers. The regular cylindrical particles in GFRP powder are found to show an anti-put-off effect which improves the medium and high-temperature performance, rutting resistance, and fatigue resistance of asphalt mastics. However, the lower density of waste GFRP powder, which takes up a higher volume ratio in asphalt mastics compared with limestone filler at the same mass ratio, has negative effects on the low-temperature performance of asphalt mastics. Waste GFRP powder can also improve the aging resistance and moisture resistance of asphalt mastics. This research provides a feasible solution for the recovery of GFRP waste with low energy consumption and pollution production. It also contributes to the sustainable development of pavement infrastructure construction. • The broken glass fiber show an anti-put off effect in asphalt mastics. • GFRP asphalt mastic has great high-temperature performance and fatigue resistance. • Waste GFRP powders can improve the aging and moisture resistance of asphalt mastics. • The positive effect of waste GFRP powder is due to its special microstructure and physical properties. [ABSTRACT FROM AUTHOR]

• AE could effectively classify the damage stages of asphalt mixture. • The main fracture of asphalt mixture was postponed after the fibers added. • Steel fiber showed superior cracking resistance of asphalt mixture. Fibers have been proven to enhance the stability and mechanical strength of asphalt mixture, but different fibers exhibited diverse characteristics of reinforcement effect. This study is set out to investigate the fiber reinforcement effect of asphalt mixture containing glass fiber reinforced asphalt mixture (GFRAM), basalt fiber reinforced asphalt mixture (BFRAM), and steel fiber reinforced asphalt mixture (SFRAM). The control asphalt mixture (CAM) was also fabricated for comparison. The fiber content was 0.5% by weight of the asphalt mixture and the specimens were manufactured following the Marshall compaction method. Indirect tensile test (IDT) and acoustic emission (AE) test at low temperature were conducted simultaneously to characterize the fracture resistance of different types of fiber reinforced asphalt mixture (FRAM). The amplitude, count, rise angle (RA), average frequency (AF), and b-value were obtained based on AE signal analysis to evaluate FRAM's reinforcement effect. The results revealed that the addition of fibers dramatically improved the strength of CAM, and the occurrence of the main fracture in FRAM emerged later than CAM. SFRAM exhibited more favorable anti-cracking performance than GFRAM and BFRAM based on the comprehensive AE signals analysis. [ABSTRACT FROM AUTHOR]

By interweaving direct rovings, 40-60 mm wide edges of the fabrics are being cut as waste. With the aim of reducing waste accumulation, several possibilities of recycling discontinuous E-glass fibres have been studied. The intention of the study was not to develop a particular product, but to test the possibilities of materials preparation when discontinuous glass fibres are added. The fibres are added to synthetic organic polymers, concrete, mortar and asphalt and their influence on materials properties was tested. [ABSTRACT FROM AUTHOR]

Lignin and glass fiber were used as additives to improve the quality of road pavements and minimize moisture damage and cracking at low temperatures on asphalt pavement, according to a previous laboratory study. The aim of this paper is to make a significant contribution to the environmental assessment of the construction of road pavements using four types of asphalt mixtures based on the life cycle assessment (LCA) methodology according to the requirements of ISO 14040, considering the impact of raw material extraction, asphalt mixture manufacturing, transportation, and wearing surface construction. The results of the environmental assessment showed that all studied asphalt mixtures do not offer any improvement in all impact categories, and three modified asphalt mixtures have a slight negative effect in all impact categories. The composite mixture has the highest negative effect of the studied three modified asphalt mixtures in all categories except in the marine aquatic ecotoxicity potential category and freshwater aquatic ecotoxicity potential category, where the lignin modified asphalt mixture has the highest negative effect in these two categories but has the best environmental impacts on most of other impact categories. Furthermore, the negative effect caused by composite asphalt mixtures is minimal and thus can be used to improve the overall performance of asphalt pavement. [ABSTRACT FROM AUTHOR]

This paper presents details of a large field trial and some observations conducted to evaluate the practical efficiencies of geosynthetically reinforced asphalt pavements in Shanxi Province, China. Three glass-fiber grids (LB2000 II, TGG-8080, GGA 2021), one plastic grid (Tensar AR1), two geotextiles (nonwoven needle-punched and nonwoven heat-bonded), and one geocomposite (Tensar AR-G) application were selected for evaluation. These geosynthetics were installed in the interface between new asphalt pavement layers (APL) and new cement-stabilized gravel–sand base courses coated by emulsified asphalt or within new APL in the reconstruction of asphalt pavement sections (Program I), or in the interface between old APL and new overlay layers in the asphalt overlay pavement sections (Program II). In each program, reinforced sections with different geosynthetics were compared with each other and with nonreinforced sections to determine relative performance. Inspections after construction showed that the integrated damage ratio and deflection in the pavement sections reinforced with glass–fiber grids were less than other pavement sections. Furthermore, after about 4 years of service, glass-fiber grids were dug out and no breaking and node movement were discovered. Nevertheless, observations indicated that geosynthetics may not be effective, if bearing capacity of the base course/subgrade is inadequate, or if the overlay thickness is too thin, or if preconstruction repair of distressed old pavement is incomplete. [ABSTRACT FROM AUTHOR]

• Aramid fiber, glass fibers, and cellulose fibers improve mechanical resistance of porous asphalt. • Even 0.05% content of aramid pulp reduced the particle loss by more than half. • Glass fiber did not influence moisture resistance, aramid fiber reduced the moisture resistance. • CRITIC-WASPAS methodology indicated aramid pulp were the best fibers. Aramid fibers and glass fibers are widely used in dense-graded asphalt mixtures to improve the mechanical characteristics. However, their effect on the characteristics of porous asphalt mixtures has not been widely explored. This study evaluated the influence of aramid fiber, aramid pulp, glass-hybrid fiber, and cellulose fiber to improve the abrasion resistance and strength of the porous asphalt mixtures while maintaining their functional characteristics. The performance of PA-16 mixtures incorporated with fibers was evaluated using the Cantabro test, permeability test, indirect tensile strength (ITS) test, and moisture susceptibility test. Finally, a multi-criteria decision method (MCDM), weighted aggregated sum product assessment (WASPAS) in combination with criteria importance through inter-criteria correlation (CRITIC) as a weighting method, is applied to make a multifaceted decision and select the best option among the variety of fibers included in the study. Results concluded aramid pulp remarkably enhanced the abrasion resistance while glass-hybrid fibers improved the ITS of the mixtures. Particularly, aramid pulp was selected as the best fiber to improve the mechanical resistance, according to the proposed methodology. [ABSTRACT FROM AUTHOR]

Nowadays, in order to improve asphalt pavement performance and durability and reduce environmental pollution caused by hydrocarbon materials, many researchers are studying different ways of modifying asphalt concrete (AC) and finding alternative paving materials to extend the service life of pavements. One of the successful materials used in the modification of AC is fibers. Different types of fibers have been reinforced in AC mixtures and improvements have been observed. This research studies the performance of glass wool fibers reinforced in a dense-graded asphalt mixture. Generally, glass fibers are known to have excellent mechanical properties such as high tensile modulus, 100% elastic recovery and a very high tolerance to heat. Glass wool fibers are commonly used as a thermal insulation material. In this research, to evaluate the performance of glass wool fibers in AC, laboratory tests, the Marshall mix design test, indirect tensile strength (IDT), tensile strength ratio (TSR) and the Kim test were conducted to determine a proper mix design, tensile properties, moisture susceptibility, rutting and fatigue behaviors. Results show that the addition of glass wool fibers does affect the properties of AC mixtures. The use of glass wool fibers shows a positive consistence result, in which it improved the moisture susceptibility and rutting resistance of the AC. Additionally, results show that the addition of fiber increased tensile strength and toughness which indicates that fibers have a potential to resist distresses that occur on a surface of the road as a result of heavy traffic loading. The overall results show that the addition of glass wool fibers in AC mixtures is beneficial in improving properties of AC pavements. [ABSTRACT FROM AUTHOR]

• The indirect strength of fibrous mix is 39.4% higher than the plain mix. • The rut-depth of fibrous mixtures satisfied the 12.5 mm specification of TxDOT. • The glass fiber is utilized as a strengthening material for the 50% recycled asphalt mixture. This study presents strengthening effect on the reclaimed hot-mix asphalt concrete associated with the reinforcement of hybrid rod-shaped glass fibers and ball-shaped glass-fiber powder to the mix. The toughening effects of the reinforced mixtures were characterized using indirect tensile, dynamic modulus, and hamburg wheel-tracking tests. The rod-shaped hybrid fibers, coated by the polypropylene resin, consist of the macro dimension of rod-shape glass fiber in 10–15 mm of length and the relatively micro size of the fiber in 4–6 mm of length separately. The ball-shaped glass fiber powder, which was coated by the polyethylene resin, was mixed with the macro and micro rod-shape fibers and the reclaimed hot-mix asphalt concrete. The indirect tensile strength test of the fibrous mixtures resulted in about 1.4 times higher strength than those of the plain mixtures. Lower moisture susceptibility, better performance of dynamic modulus at low and high temperatures and superior rut resistance of the fibrous asphalt mixtures were also observed. [ABSTRACT FROM AUTHOR]

• The cracking resistance of asphalt mixtures declines by adding RAP at 0 °C and 15 °C. • Glass fibers are beneficial for enhancing the cracking resistance of asphalt mixtures. • The positive effect of glass fibers can compensate for the adverse impact of RAP material. • The use of RAP material improves cracking performance at −15 °C. Escalating the price of asphalt binder and environmental issues have led to an increasing desire to use high amounts of reclaimed asphalt pavement (RAP) material in asphalt mixtures. However, increasing the RAP content may have negative effects on some characteristics of asphalt mixtures, such as cracking resistance. Therefore, finding an approach to compensate for the negative impacts of RAP material may be considered as a solution to raise the RAP content in asphalt mixtures. Fibers are known as one of the modifiers that are added directly to the mixtures and enhance the cracking resistance of asphaltic materials. Therefore, in this study, the cracking behavior of asphalt mixtures containing different percentages of RAP material in combination with glass fibers was investigated using the semi-circular bending (SCB) fracture tests at temperatures of −15, 0 and 15 °C. The results showed that using up to 0.12% glass fiber leads to a significant enhancement in resistance of all mixtures against crack initiation and propagation. Moreover, it was found that the negative impact of RAP material on the crack resistance of asphalt mixtures is reversible to a great extent using 0.12% glass fiber, and 100% RAP mixtures are applicable without any significant reduction in crack resistance. [ABSTRACT FROM AUTHOR]