scholarly journals Effects of Carbon Fibre on Performance Properties of Asphalt Mixtures

2020 ◽  
Vol 15 (2) ◽  
pp. 49-65 ◽  
Author(s):  
Tacettin Geckil ◽  
Perviz Ahmedzade
Keyword(s):  
Carbon Fibre ◽  
Permanent Deformation ◽  
Asphalt Mixtures ◽  
Asphalt Pavements ◽  
Positive Contribution ◽  
Stiffness Modulus ◽  
Performance Properties ◽  
Creep Stiffness ◽  
Indirect Tensile ◽  
Marshall Stability

In this study, the effects of carbon fibre on improving the performance characteristics of asphalt mixtures were investigated. To this end, four percentages of carbon fibre (0%, 0.3%, 0.5%, and 0.7% by weight of bitumen) were used as an additive in asphalt mixtures. The mechanical properties of prepared mixture specimens were investigated using tests such as Marshall Stability and flow, Indirect Tensile Stiffness Modulus, Creep Stiffness, Indirect Tensile Strength, and moisture resistance. The results of tests applied to asphalt mixtures showed that the carbon fibre additive increased the resistance to shear stress by 25%, the fatigue life by 51% at 40 °C and the permanent deformation resistance by 2.25 times at 60 °C. It also improved the resistance of mixtures to moisture damage by increasing the durability and cohesion of asphalt mixtures. Experimental results indicated that the carbon fibre provided a positive contribution to the performance properties of asphalt pavements.

scholarly journals Asphalt concrete mixtures with addition of reclaimed asphalt pavements

2021 ◽  
Author(s):  
Piotr Zieliński
Keyword(s):  
Tensile Strength ◽  
Asphalt Concrete ◽  
Asphalt Mixtures ◽  
Indirect Tensile Strength ◽  
Asphalt Pavements ◽  
Stiffness Modulus ◽  
Reclaimed Asphalt ◽  
Concrete Mixtures ◽  
Indirect Tensile ◽  
Reclaimed Asphalt Pavements

The effect of using reclaimed asphalt pavements (RAP) to asphalt concrete mixtures besides their utilization is to reduce the amount of the new bituminous binder and aggregate added to hot mix asphalt. This publication presents studies on asphalt mixtures with an increased up to 40% amount of RAP additive with the simultaneous use of 2 types of added bitumen, i.e. 35/50 and PMB 25/55-60. The aim of the paper is the evaluation of the basic mixture properties in a wide range of operating temperatures, as a part of the AC testing at high temperatures, the resistance to rutting at 60° C and indirect tensile strength at 40° C. The assessment of properties at intermediate operating temperatures is based on indirect tensile tests, including: elastic stiffness modulus at 5° C, 15° C and 30° C and static strength at 25° C. The low temperature properties have been tested in water and frost resistance tests by indirect tensile strength ratio. The results of the study were subjected to the analysis of the statistical significance of differences, which showed an improvement in the resistance of AC with the addition of RAP to the formation of permanent deformations and an increase in the stiffness modulus as well as indirect tensile strength. There was no adverse effect of the RAP additive on asphalt mixtures resistance to water and frost action.

Mechanical Properties of Asphalt Mixture Reinforced with Cellulose-Polyester Hybrid Fibers

2012 ◽  
Vol 509 ◽  
pp. 142-148 ◽  
Author(s):  
Zheng Chen ◽  
Deng Cheng Ma
Keyword(s):  
Permanent Deformation ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Hybrid Fibers ◽  
Moisture Sensitivity ◽  
Moisture Susceptibility ◽  
Polyester Fibers ◽  
Pet Fibers ◽  
Indirect Tensile ◽  
Marshall Stability

With regards of discussing cellulose and polyester fibers reinforced asphalt mixtures, the contribution of cellulose (CEL) and polyester (PET) fibers had therefore been experimented. And on the basis of different reinforcement mechanisms, this research focused on the cellulose (CEL) - polyester (PET) hybrid fibers reinforced system, consequently determined the feasibility of utilizing CEL-PET hybrid fibers in asphalt mixture. Asphalt mixtures had been prepared, according to the specifications, following both the SHRP procedure and the traditional one. Mechanical characteristics of the mixtures were evaluated with Marshall stability (MS), indirect tensile strength (ITS), moisture sensitivity, high temperature rutting test and fatigue test. This study compared the performance of mixtures containing hybrid fibers with mixes made with and without commonly used cellulose and polyester fibers produced specifically for use in hot mix asphalt (HMA). The research results showed that no significant differences in MS, ITS or moisture susceptibility were found in mixtures containing hybrid fibers compared to cellulose or polyester. Also, the hybrid fibers significantly improved the permanent deformation resistance of the mixtures compared to cellulose fibers, say nothing of the control one without fibers.

scholarly journals Laboratory Evaluation of the Use of Florida Washed Shell in Open-Graded Asphalt Mixtures

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7060
Author(s):  
Mohammad Alharthai ◽  
Qing Lu ◽  
Ahmed Elnihum ◽  
Asad Elmagarhe
Keyword(s):  
Tensile Strength ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Indirect Tensile Strength ◽  
Laboratory Evaluation ◽  
Void Content ◽  
Coarse Aggregates ◽  
Significant Difference ◽  
Indirect Tensile ◽  
Marshall Stability

This study investigates the substitution of conventional aggregate with a Florida washed shell in open-graded asphalt mixtures and evaluates the optimal substitution percentage in aggregate gradations of various nominal maximum aggregate sizes (NMASs) (i.e., 4.75, 9.5, and 12.5 mm). Laboratory experiments were performed on open-graded asphalt mixture specimens with the coarse aggregate of sizes between 2.36 and 12.5 mm being replaced by the Florida washed shell at various percentages (0, 15, 30, 45, and 100%). Specimen properties relevant to the performance of open-graded asphalt mixtures in the field were tested, evaluated, and compared. Specifically, a Marshall stability test, Cantabro test, indirect tensile strength test, air void content test, and permeability test were conducted to evaluate the strength, resistance to raveling, cracking resistance, void content, and permeability of open-graded asphalt mixtures. The results show that there is no significant difference in the Marshall stability and indirect tensile strength when the coarse aggregates are replaced with Florida washed shell. This study also found that the optimum percentages of Florida washed shell in open-graded asphalt mixture were 15, 30, and 45% for 12.5, 9.5, and 4.75 mm NMAS gradations, respectively.

scholarly journals Effect of Hydrated Lime on Indirect Tensile Stiffness Modulus of Asphalt Concrete Produced in Half-Warm Mix Technology

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4731
Author(s):  
Mateusz M. Iwański
Keyword(s):  
Asphalt Concrete ◽  
Permanent Deformation ◽  
Active Agent ◽  
Hydrated Lime ◽  
Partial Replacement ◽  
Stiffness Modulus ◽  
Limestone Filler ◽  
Tensile Stiffness ◽  
Lime Content ◽  
Indirect Tensile

Half-warm mix asphalt (HWMA) mixtures can be produced at temperatures ranging from 100 °C to 130 °C, depending on the production methods used. The lowest mixing temperature can be achieved by using water-foamed bitumen. The mixture should be characterized by a long service life, defined by the resistance to permanent deformation and high stiffness modulus at temperatures above zero. It is therefore important to ensure the adequately high quality of the bitumen binder. Bitumen 50/70 was provided with appropriate quality foaming characteristics (expansion ratio, ER, half-life, t1/2) by adding a surface-active agent (SAA) at 0.6 wt % before foaming. Then asphalt concrete (AC) 8 S was designed and produced with the recommended water-foamed binder. Hydrated lime, an additive substantially affecting asphalt concrete mechanical parameters, was used at 0, 15, 30, and 45 wt % as a partial replacement for the limestone filler. The influence of the amount of hydrated lime on the content of voids, indirect tensile stiffness modulus at −10 °C, 0 °C, +10 °C, +20 °C, and +30 °C, and the resistance to permanent deformation was investigated. Statistical analysis of the test results showed the quantity of 30% to be the optimum hydrated lime content. The AC 8 S resistance to permanent deformation was determined at the optimum hydrated lime content. The comprehensive evaluation revealed a synergistic effect between bitumen 50/70, modified before foaming with 0.6 wt % SAA and 30 wt % hydrated lime as the limestone filler replacement, and the half warm mixture AC 8 S, in terms of the standard requirements and durability of the HWMA concrete in pavement applications.

scholarly journals An investigation on the effects of flaky particles on the properties of asphaltic mixtures

2015 ◽  
Vol 42 (11) ◽  
pp. 865-871 ◽  
Author(s):  
Babak Kazemi Darabadi ◽  
Hasan Taherkhani
Keyword(s):  
Creep Behaviour ◽  
Permanent Deformation ◽  
Asphaltic Concrete ◽  
Test Results ◽  
Creep Tests ◽  
Air Voids ◽  
Static Creep ◽  
Different Types ◽  
Creep Stiffness ◽  
Marshall Stability

Flaky particles, because of their shape, are considered as inferior aggregates in asphaltic mixtures, and specifications usually set limits on the amount of flaky particles in asphaltic mixtures. In this study, the effects of flaky particles content on the volumetric properties, Marshall Stability and creep behaviour of hot mixed asphaltic concrete have been investigated. Specimens with two different types of gradation and specified amounts of flaky particles were made and used for Marshall Stability and static creep tests. Test results show that the Marshall Stability decreases and the air voids content of asphaltic mixture and the voids in mineral aggregate increase as the flaky particles content increases. It is also found that flaky particles cause increase in permanent deformation and decrease in creep stiffness. The creep tests also show that the recoverable deformation of the mixtures decreases as the flaky particles content increases.

scholarly journals Influence of Natural Fibers on the Performance of Hot Mix Asphalt for the Wearing Course of Pavement

2020 ◽  
Vol 8 (2) ◽  
pp. 57-63
Author(s):  
Omar T. Mahmood ◽  
Sheelan A. Ahmed
Keyword(s):  
Tensile Strength ◽  
Hot Mix Asphalt ◽  
Natural Fiber ◽  
Natural Fibers ◽  
Flexible Pavement ◽  
Asphalt Mixtures ◽  
Palm Fiber ◽  
Marshall Test ◽  
Indirect Tensile ◽  
Marshall Stability

Cracking in the flexible pavement is a serious problem that reduces the service life of the roads pavement unless they are treated with great care. Since flexible pavement is very weaker in tension than in compression, it is usually necessary to consider the tensile stresses and some type of additives to improve asphaltpavement performance, and one of the most effective ways of improving asphalt pavement performance is to reinforce asphalt mixtures by incorporating natural fibers. The main objective of this study is to use palm fiber, which is locally available, in hot mix asphalt mixtures. To achieve this objective, the Marshall test and indirect tensile strength test were conducted on four asphalt mixtures with different types of natural fibers (Coconut, Corn, Palm, and Sisal), added in varying percentages 0.1, 0.2, 0.3, 0.4, and 0.5% and different lengths of fiber 0.5, 1, 1.5, and 2 cm. Based on the analyzed results, it can be concluded that the use of palm fiber increased the Marshall stability by 20% as compared with the conventional mixture and raised up the retained tensile strength ratio up to 92%. Finally, the use of 0.2% content of natural fiber at 1.5 cm length gave a better performance for the mixtures.

scholarly journals Further Investigation on Damage Model of Eco-Friendly Basalt Fiber Modified Asphalt Mixture under Freeze-Thaw Cycles

2018 ◽  
Vol 9 (1) ◽  
pp. 60 ◽  
Author(s):  
Wensheng Wang ◽  
Yongchun Cheng ◽  
Guirong Ma ◽  
Guojin Tan ◽  
Xun Sun ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Asphalt Mixture ◽  
Basalt Fiber ◽  
Asphalt Mixtures ◽  
Splitting Tensile Strength ◽  
Stiffness Modulus ◽  
Freeze Thaw ◽  
Damage Characteristics ◽  
Indirect Tensile

The main distresses of asphalt pavements in seasonally frozen regions are due to the effects of water action, freeze-thaw cycles, and so on. Basalt fiber, as an eco-friendly mineral fiber with high mechanical performance, has been adopted to reinforce asphalt mixture in order to improve its mechanical properties. This study investigated the freeze-thaw damage characteristics of asphalt mixtures reinforced with eco-friendly basalt fiber by volume and mechanical properties—air voids, splitting tensile strength, and indirect tensile stiffness modulus tests. Test results indicated that asphalt mixtures reinforced with eco-friendly basalt fiber had better mechanical properties (i.e., splitting tensile strength and indirect tensile stiffness modulus) before and after freeze-thaw cycles. Furthermore, this study developed logistic damage models of asphalt mixtures in terms of the damage characteristics, and found that adding basalt fiber could significantly reduce the damage degree by about 25%, and slow down the damage grow rate by about 45% compared with control group without basalt fiber. Moreover, multi-variable grey models (GM) (1,N) were established for modelling the damage characteristics of asphalt mixtures under the effect of freeze-thaw cycles. GM (1,3) was proven as an effective prediction model to perform better in prediction accuracy compared to GM (1,2).

Study on Strength Characteristics Improvement of Polyethylene Modified Bituminous Concrete Mixes

2019 ◽  
Vol 803 ◽  
pp. 216-221
Author(s):  
Khwairakpam Lakshman Singh ◽  
Debjani Panda
Keyword(s):  
Tensile Strength ◽  
Permanent Deformation ◽  
Indirect Tensile Strength ◽  
Strength Characteristics ◽  
Strength Ratio ◽  
Modified Binders ◽  
Indirect Tensile ◽  
Modified Binder ◽  
Marshall Stability ◽  
Bituminous Concrete

The present study shows an investigation on improvement of bituminous binder and its mixes using modified binders with different percentage (1% to 7%) of domestic waste polyethylene (PE).The temperature susceptibility and penetration index (PI) of the modified binders were calculated. It is observed that PI value of modified binder is found higher than unmodified binder. The strength characteristics in terms of Marshall Stability and moisture susceptibility expressed in terms of indirect tensile strength ratio (ITSR) of bituminous concrete were determined in the present study. Marshall stability of the bituminous mixture containing 3% PE increased by 34.2% as compare to mixture containing unmodified binder. The addition of 3% PE to neat bitumen, results in an increase of 20% in indirect tensile strength ratio. Using PE modified binder in bituminous concrete mixes increases stability, indirect tensile strength which turn in provide better resistance against permanent deformation.

Effect of Modified Asphalt Cement of the Performance of Stone Matrix Mixtures

2020 ◽  
Vol 38 (5A) ◽  
pp. 789-800
Author(s):  
Duaa A. Khalaf ◽  
Zaynab I. Qasim ◽  
Karim H. Al Helo
Keyword(s):  
Tensile Strength ◽  
Fracture Resistance ◽  
Laboratory Tests ◽  
Asphalt Binder ◽  
Asphalt Mixtures ◽  
Indirect Tensile Strength ◽  
Asphalt Cement ◽  
Indirect Tensile ◽  
Marshall Stability ◽  
Stone Matrix

This research investigates the behavior of Stone Matrix Asphalt mixtures (SMA) modified with styrene-butadiene-styrene (SBS) polymer at four percentages (1, 2, 3 and 4%) by weight of asphalt cement. The moisture susceptibility and rutting were taken into consideration in this study. To achieve the objective of this research the superpave system is conducted to design the asphalt mixtures. The physical properties of aggregate, bitumen and other mix materials were assessed and evaluated with the laboratory tests. The mixtures were prepared using penetration Graded (40-50) bitumen and a chemical named Polypropylene Fibers was used as a stabilizing additive. Fibers have been used in SMA mixtures for two main reasons: To increase the toughness and fracture resistance of hot mix asphalt (HMA) and to act as a stabilizer to prevent drain down of the asphalt binder. The laboratory tests include indirect tensile strength test, Marshall stability and retained Marshall Stability test (RMS). For rutting test the Roller wheel compactor is used for preparing the asphaltic samples and Wheel tracking device is used to evaluate the rutting of asphaltic slabs. The results showed that the SBS polymer asphalt mixture gave better moisture sensitivity and better fracture resistance according to the study.It is noted that indirect tensile strength ratio (TSR) increases by 93.1 % and the rut depth decreases by 32.5 % when adding 3% SBS polymer to SMA.

scholarly journals Preliminary Evaluation of Hot Mix Asphalt Containing Reclaimed Epoxy Asphalt Materials

2020 ◽  
Vol 12 (9) ◽  
pp. 3531
Author(s):  
Mohammed Alamri ◽  
Qing Lu ◽  
Chunfu Xin
Keyword(s):  
Hot Mix Asphalt ◽  
Asphalt Mixtures ◽  
Asphalt Pavements ◽  
Preliminary Evaluation ◽  
Reclaimed Asphalt ◽  
Coarse Aggregates ◽  
Epoxy Asphalt ◽  
Asphalt Materials ◽  
Long Life ◽  
Marshall Stability

Designing long-life pavements and pavement recycling with reclaimed asphalt pavement (RAP) are two important strategies for improving the sustainability of asphalt pavements. Epoxy asphalt, as a proven long-life pavement material, is attracting attention from the pavement community for its use in road pavements. The recyclability of epoxy asphalt mixtures, however, has never been studied and has now become one concern in promoting the use of epoxy asphalt in road pavements. This study attempts to explore the performance of hot mix asphalt (HMA) containing reclaimed epoxy asphalt materials. Reclaimed epoxy asphalt was fabricated in the laboratory and incorporated into regular asphalt mixtures at various contents. Specimens were prepared and tested for their performance in comparison with mixtures without RAP. It was found that replacing the coarse aggregates in HMA with epoxy RAP up to 80% did not negatively affect its Marshall stability, tensile strength, and moisture resistance. The plastic deformation at failure of HMA, however, may increase with the increase in epoxy RAP content. At the current stage, the results from this study do not provide evidence to invalidate the use of epoxy RAP in HMA, at least at a coarse aggregate replacement rate of less than 40%.

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