scholarly journals Effect of aging on the physical-mechanical characteristics of an asphalt mixture with rubber

2021 ◽  
Vol 2102 (1) ◽  
pp. 012020
Author(s):  
J G Bastidas-Martínez ◽  
J C Ruge ◽  
R A G Zuluaga ◽  
L Medina

Abstract This paper evaluated the physical-mechanical characteristics of two asphalt mixtures. One mix with conventional asphalt and the other with asphalt modified with recycled rubber grain. For this purpose, the asphalt mix designs were made by means of the Marshall methodology. Subsequently, asphalt mixtures were manufactured to analyze the action of monotonic loads (indirect tensile strength) and dynamic loads (resilient modulus). Previously, each type of asphalt mix was subjected to short- and long-term aging conditions, following Aastho guidelines. It is concluded that the incorporation of recycled rubber grain makes the changes in mechanical properties with aging not very noticeable in relation to mixtures without this material.

2019 ◽  
Vol 81 (6) ◽  
Author(s):  
Norfazira Mohd Azahar ◽  
Norhidayah Abdul Hassan ◽  
Ramadhansyah Putra Jaya ◽  
Hasanan Md. Nor ◽  
Mohd Khairul Idham Mohd Satar ◽  
...  

The use of cup lump rubber as an additive in asphalt binder has recently become the main interest of the paving industry. The innovation helps to increase the natural rubber consumption and stabilize the rubber price. This study evaluates the mechanical performance of cup lump rubber modified asphalt (CMA) mixture in terms of resilient modulus, dynamic creep and indirect tensile strength under aging conditions. The CMA mixture was prepared using dense-graded Marshall-designed mix and the observed behavior was compared with that of conventional mixture. From the results, both mixtures passed the volumetric properties as accordance to Malaysian Public Work Department (PWD) specification. The addition of cup lump rubber provides better resistance against permanent deformation through the enhanced properties of resilient modulus and dynamic creep. Furthermore, the resilient modulus of CMA mixture performed better under aging conditions.  


2019 ◽  
Vol 5 (2) ◽  
pp. 320
Author(s):  
Gholam Hossein Hamedi

Several parameters affect asphalt mix performance against loading and environmental conditions. Minor changes in the filler amount or type can cause obvious changes in the asphalt mixture properties. Accordingly, in this research attempts have been made to optimally make asphalt mixture strong against loading and environmental conditions by changing the type, size and percentage of filler used in asphalt mixture. In this line, the effect of two types of cement and nano-silica fillers in two different percentages was investigated and compared as an alternative for part of the main filler in asphalt mixture samples made by two types of limestone and granite aggregate. Cement filler by 2% and 4% of the aggregate mass as the alternative for part of the main filler is added to stone materials before mixing with binder, but nano-silica filler by 2% and4 % of weight of the binder as the alternative for part of the main filler is added to binder and a modified and homogeneous binder is produced using a high speed mixer. In the following, considering the optimum binder content for each mixture, resilient modulus tests were conducted to determine the strength performance against loading and indirect tensile strength ratio was used to determine moisture sensitivity of asphalt mixtures. Results obtained from resilient modulus tests show that the use of nano-silica and cement has been capable of favorably improving the resilient modulus of samples containing these two types of fillers. The improvement of the resilient modulus of samples containing nano-silica is very significant. Additionally, the studies conducted based on the indirect tensile strength ratio show that both types of alternative fillers, especially cement has been capable of desirably improve the strength of asphalt mixtures against moisture damage.


Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1738 ◽  
Author(s):  
Hongyin Li ◽  
Hailong Jiang ◽  
Wenwu Zhang ◽  
Peng Liu ◽  
Shanshan Wang ◽  
...  

Resistance of asphalt mix to low-temperature cracking and rutting at high temperature is very important to ensure the service performance of asphalt pavement under seasonal changes in temperature and loading. However, it is challenging to balance the improvement of such resistance by using additives, e.g., anti-rutting agent (ARA). This study focuses on improving the flexibility of anti-rutting asphalt mix by incorporating crumb rubber (CR) and ARA. The properties of the prepared modified asphalt mix were evaluated in the laboratory by performing wheel tracking, three-point bending, indirect tensile, and uniaxial compression tests. The experimental results showed that the dynamic stability of modified asphalt mix was significantly increased due to the addition of ARA and further improved by incorporating CR. The maximum bending strain at −10 °C was increased due to the contribution of CR. The results of indirect tensile strength and resilient modulus further indicated that the CR-modified anti-rutting mixture was more flexible. Moreover, the field observation and evaluation indicated that the CR-modified anti-rutting asphalt pavement met the standard requirements, better than normal asphalt mixture in many parameters. A conclusion can be made that incorporating CR in asphalt mixture prepared with ARA can improve pavement performance at both high and low in-service temperatures.


2014 ◽  
Vol 70 (4) ◽  
Author(s):  
Mohd Zul Hanif Mahmud ◽  
Haryati Yaacob ◽  
Ramadhansyah Putra Jaya ◽  
Norhidayah Abdul Hassan

This paper presents an investigation on the effects of flaky aggregates in asphalt mixture. In general, aggregate characteristics are critical to the performance of asphalt mixture. Therefore, flaky aggregate is normally avoided simply because it has significant contribution towards the gradation and reduces the interlocking characteristics of aggregates within asphalt mixture. In practice, it is recommended that the amount of flakiness aggregate should be limited to 25% or less. This study evaluates the mechanical properties of asphalt mixture specimens prepared with various percentages of flaky aggregates particularly 10%, 20% and 30% by the total weight of the mixture. Several laboratory tests were conducted including Marshall properties test, Indirect Tensile Modulus test and Dynamic Creep test. The results show that higher bitumen content is required with the increased in the amount of flaky aggregates added to mixture. Furthermore, greater amount of flaky aggregates tends to reduce the mixture’s resilient modulus and its resistance against permanent deformation.


Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7060
Author(s):  
Mohammad Alharthai ◽  
Qing Lu ◽  
Ahmed Elnihum ◽  
Asad Elmagarhe

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.


2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Yongjoo Kim ◽  
Jaejun Lee ◽  
Cheolmin Baek ◽  
Sunglin Yang ◽  
Sooahn Kwon ◽  
...  

A number of warm-mix asphalt (WMA) technologies are used to reduce the temperature at which the asphalt mixtures are produced and compacted, apparently without compromising the performance of the pavement. The main objective of this study is to determine whether the use of an innovative wax-based LEADCAP WMA additive influences the performance of the asphalt mixture, which is produced and compacted at significantly low temperatures. The WMA pavement using LEADCAP additive (WMA-LEADCAP) along with a control HMA pavement was evaluated with respect to their performances of rutting resistance, crack resistance, and viscoelastic property based on the laboratory dynamic modulus test, indirect tensile strength test, and in-door accelerated pavement test (APT) results. With the limited data carried out, the LEADCAP additive is effective in producing and paving asphalt mixture at approximately 30°C lower temperature than a control HMA mixture, and the performances of WMA-LEADCAP pavement are comparable to a control HMA pavement.


2011 ◽  
Vol 255-260 ◽  
pp. 3432-3436
Author(s):  
Xian Yuan Tang ◽  
Jie Xiao

This paper systematically elaborates the impact upon performance of emulsion asphalt cold reclaimed asphalt mixture by different RAP contents, through a series of testing on six cold reclaimed asphalt mixtures with various RAP contents, such as single axle compression test, 15°C indirect tensile strength (ITS) test, 40°C rutting test and -10°C low-temperature bending beam test. Testing results indicate that 15°C ITS decreases from around 0.75 MPa to 0.58 MPa with the RAP content of mixture increasing from 0% to 100%. 40°C dynamic stabilities reduce considerably from around 19,000 time/mm of 0% RAP mixture to 3,600 time/mm of 100% RAP mixture. -10°C failure strains only change from 1500με to 2000με.


2016 ◽  
Vol 700 ◽  
pp. 227-237 ◽  
Author(s):  
Siti Nur Amiera Jeffry ◽  
Ramadhansyah Putra Jaya ◽  
Norhafizah Manap ◽  
Nurfatin Aqeela Miron ◽  
Norhidayah Abdul Hassan

Significant quantities of coconut shell (CS), a by-product of agriculture, can be used as an artificial source of coarse aggregates. In this study, four CSs were used as coarse aggregates replacement in asphalt concrete with 0%, 10%, 20%, 30%, and 40% weight volumes. The particle sizes of the CSs used as main coarse aggregates range from 5 mm to 20 mm. The Marshall Stability test shows that the optimum bitumen content for asphalt mixtures is 5.1%. The engineering properties investigated include the volumetric, dynamic creep, indirect tensile strength, and resilient modulus. Test results show that stability decreases with increasing CS content because of high water absorption. Considering that CSs absorb bitumen, a further detailed investigation is needed to assess the performance of modified bitumen on mixture. Furthermore, the use of CSs as coarse aggregates in asphalt concrete help increase the resilient modulus, stiffness, and indirect tensile strength up to 30%. Generally, a 10% replacement of coarse aggregates with CSs is the optimal limit.


2018 ◽  
Vol 9 (1) ◽  
pp. 60 ◽  
Author(s):  
Wensheng Wang ◽  
Yongchun Cheng ◽  
Guirong Ma ◽  
Guojin Tan ◽  
Xun Sun ◽  
...  

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).


Author(s):  
Taesoon Park ◽  
Brian J. Coree ◽  
C. W. Lovell

The viability of using pyrolized carbon black (CBp) derived from waste tires as a reinforcing agent in asphalt mixtures was evaluated. Commercial carbon black (CB) has been previously shown to reduce the rutting resistance, temperature susceptibility, and cracking propagation potential of asphalt concrete. It was believed that CBp could produce similar benefits; this belief has been confirmed by this study. Different ratios of CBp and CB (5, 10, 15, and 20 percent by weight of asphalt) were blended with two grades of asphalt (AC-10 and AC-20). The Marshall method, the gyratory testing machine, the dynamic creep testing (confined), the indirect tensile testing, and the resilient modulus test were performed. The test results of CBp mixtures were compared with results of CB and conventional mixtures. The analyses of test results show that the typical performance of CBp-modified asphalt mixtures is improved with respect to commercial CB and conventional mixtures. The rutting potential and the temperature susceptibility can be reduced by the inclusion of CBp in the asphalt mixture. A CBp content of 10 to 15 percent by weight of asphalt is recommended for improvement of asphalt concrete.


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