scholarly journals The Effect of Ageing on Chemical and Mechanical Properties of Asphalt Mortar

2018 ◽  
Vol 8 (11) ◽  
pp. 2231 ◽  
Author(s):  
Ruxin Jing ◽  
Xueyan Liu ◽  
Aikaterini Varveri ◽  
Athanasios Scarpas ◽  
Sandra Erkens
Keyword(s):  
Mechanical Properties ◽  
Asphalt Mixtures ◽  
Pavement Performance ◽  
Frequency Sweep ◽  
Carbonyl Index ◽  
Mineral Particles ◽  
Tension Tests ◽  
Ftir Spectrometry ◽  
Diffusion Paths ◽  
Asphalt Mortar

Asphalt mortar is a mixture of bitumen, filler, and sand. Mortar plays an important role in asphalt mixtures as it serves as the adhesive between the coarser aggregates. Due to the effect of bitumen ageing, the chemical and mechanical properties of asphalt mortar evolve with time. The mortar becomes more brittle and prone to cracking, thus leading to inferior pavement performance. In this study, Fourier transform infrared (FTIR) spectrometry was used to quantify changes in the chemical functional groups related to ageing and to calculate the carbonyl and sulfoxide indices. In addition, frequency sweep tests and uniaxial tension tests were performed by means of dynamic shear rheometer (DSR) tests to determine evolution of the stiffness and strength due to ageing. Two different oven ageing protocols were used to evaluate the effect of fine mineral particles on bitumen ageing. The protocols differed with respect to the order of ageing and mixing of the constituents. The results showed that both the chemical and mechanical properties of mortars significantly changed with ageing. Specifically, the carbonyl index, stiffness, and strength of the mortar increased. Under the same ageing conditions, a higher ageing level was observed for mortars produced by first mixing and then ageing compared to the mortars produced by mixing aged bitumen with filler and sand. This could be due to the presence of sand and filler particles, which resulted in an increased length of diffusion paths and consequently a slower ageing process.

scholarly journals Evaluation of Short-Term Aging Protocol for Asphalt Mixtures

2019 ◽  
Vol 9 (14) ◽  
pp. 2783 ◽  
Author(s):  
Sirin ◽  
Paul ◽  
Kassem ◽  
Ohiduzzaman
Keyword(s):  
Mechanical Properties ◽  
Asphalt Pavement ◽  
Road Construction ◽  
Asphalt Mixtures ◽  
Pavement Performance ◽  
Design Stage ◽  
Construction Site ◽  
Short Term ◽  
Compaction Processes

Asphalt mixtures are subjected to short-term aging during the production, placement, and compaction processes. Proper evaluation of asphalt pavement performance relies on the accurate characterization of asphalt mixtures during the design stage. In this study, three different loose asphalt mixtures often used in Qatar were evaluated to develop a laboratory short-term aging procedure. Sample mixtures 1 and 3 were collected from a construction site, while mixture 2 was obtained from an asphalt plant. Virgin aggregates and binders were also collected to reproduce the mixtures in the laboratory. Laboratory-produced mixtures were conditioned at 135 °C using various time durations. The mechanical properties of laboratory-produced mixtures were compared to those of mixtures produced on site. The results of the mechanical and binder testing demonstrated that the proper short-term aging protocol for asphalt mixtures often used in road construction in the State of Qatar would involve heating asphalt mixtures for 4 h at 135 °C before laboratory compaction.

Precision of Shear Tests in Evaluating Asphalt Mixtures

2003 ◽  
Vol 1832 (1) ◽  
pp. 155-160 ◽  
Author(s):  
R. Michael Anderson ◽  
Richard K. Steger ◽  
Gerald A. Huber ◽  
Pedro Romero
Keyword(s):  
Mechanical Properties ◽  
Hot Mix Asphalt ◽  
Shear Stiffness ◽  
Asphalt Mixtures ◽  
Shear Tests ◽  
Frequency Sweep ◽  
Constant Height ◽  
Repeated Load ◽  
Shear Tester ◽  
Highway Research

Various methods exist to measure the mechanical properties of hot-mix asphalt (HMA). To be useful such a test not only must measure a property that controls performance but also must be repeatable. The Strategic Highway Research Program developed tests with the Superpave® shear tester that have been shown to be related to HMA performance. To date, repeatability has not been quantified. The results of a repeatability study for the measurement of shear stiffness (frequency sweep) and of permanent shear strain (repeated-load, constant-height testing) are reported.

scholarly journals Karakteristik Marshall Pada Campuran Asphalt Concrete – Wearing Course (AC-WC) Dengan Penambahan Styrofoam

2019 ◽  
Vol 8 (2) ◽  
pp. 51-62
Author(s):  
Ika Sulianti ◽  
Ibrahim Ibrahim ◽  
Agus Subrianto ◽  
Adelia Monita ◽  
Medici Medici
Keyword(s):  
Asphalt Concrete ◽  
Asphalt Pavement ◽  
Flexible Pavement ◽  
Asphalt Mixtures ◽  
Concrete Mixture ◽  
Pavement Performance ◽  
Food Container ◽  
Optimum Stability ◽  
Marshall Test

Styrofoam waste presents the environment issue because it is difficult to decompose. As an effort to recycle this pollutant, styrofoam can be utilized as an additive in asphalt concrete mixture. The use of additives aims to create a flexible pavement layer having good performance and meet the requirements. The purpose of this study is to find out whether the addition of styrofoam can improve the quality of asphalt mixtures, and look for alternative additives that can increase asphalt pavement performance. In this study, researchers used food container styrofoam as an addition and incorforated into Asphalt Concrete Wearing Course (AC-WC) mixture. The styrofoam content was 6.5%; 6.75%; 7% ; 7.25%; and 7.5% of asphalt weight. The optimum asphalt contentused is 5.5%. The value of the optimum stability was 3126,002 kg, found at 7.25% of styrofoam content. The best results of Marshall test was obtained at 6.5% of styrofoam content  with stability value  1362,045 kg, VIM value 4,96%, VMA 15,025%, VFA 67,800%, flow 3,44 mm, and MQ 416,338 kg / mm.

Laboratory Study of Pavement Performance of Basalt Fiber-Modified Asphalt Mixture

2011 ◽  
Vol 266 ◽  
pp. 175-179 ◽  
Author(s):  
Yuan Xun Zheng ◽  
Ying Chun Cai ◽  
Ya Min Zhang
Keyword(s):  
Asphalt Mixture ◽  
Basalt Fiber ◽  
Temperature Stability ◽  
Asphalt Mixtures ◽  
Polyester Fiber ◽  
Pavement Performance ◽  
High Temperature Stability ◽  
Modified Asphalt ◽  
And Control ◽  
Temperature Crack

In order to discuss the effect of the basalt fiber on reinforcing pavement performance of asphalt mixtures, the optimum dosage of asphalt and fibers were studied by the method of Marshall test and rut test firstly. Then pavement performances of basalt fiber-modified asphalt mixtures were investigated through tests of high temperature stability, water stability and low temperature crack resistance, and compared with that of polyester fiber, xylogen fiber and control mixture. The testing results showed that the pavement performance of fiber-modified asphalt mixture are improved and optimized comparing with control asphalt mixture, and the performance of basalt fiber-modified asphalt mixture with best composition were excelled than those of polyester fiber and xylogen fiber.

scholarly journals Properties of Asphalt Mixtures Using Reclaimed Asphalt Containing Polymer-Modified Binder and Technicoeconomical Considerations of Their Use

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Jan Mikolaj ◽  
Frantisek Schlosser ◽  
Lubos Remek ◽  
Martin Pitoňák ◽  
Juraj Šrámek
Keyword(s):  
Plastic Deformation ◽  
Laboratory Testing ◽  
Asphalt Mixtures ◽  
Pavement Management ◽  
Bending Test ◽  
Pavement Performance ◽  
Stiffness Modulus ◽  
Reclaimed Asphalt ◽  
Modified Binder

The article summarises findings from laboratory testing of asphalt mixtures using reclaimed asphalt containing polymer-modified binder and subsequent technicoeconomical considerations of their use in pavement management system. Tested mixtures had 0%, 15%, and 40% content of reclaimed asphalt (RA) containing polymer-modified bitumen (PMB) obtained by milling from surfacing layers of existing PA, AC11, and SMA11 pavement layers. A complete description of these mixtures is given, and testing methods used are described. The mixtures were tested for air void content, ITSR water sensitivity test, plastic deformation wheel tracking test, stiffness of the tested mixtures, and two-point bending test to ascertain fatigue. Concise and succinct conclusions from laboratory testing are derived and used as an input in the second part of the article. It is found that the addition of RA containing PMB increased stiffness modulus of the final mixture, which increases resistance to plastic deformation and leads to higher brittleness at low temperatures. It is found that virgin PMB also increases fatigue resistance as opposed to PMB content from reclaimed materials. In the second part of the article, findings from laboratory testing are addressed in the context of their practical use in pavement management. The key element identified, having a direct impact on pavement performance models, was the stiffness modulus for mixtures with different PMB-reclaimed asphalt contents. A method is described to evaluate pavement construction properties related to wearing course materials via the pavement performance model. Practical use of this method is described and applied in a case study. In this case study, the proposed method is used to evaluate the issues regarding practical use of asphalt mixtures with different ratios of reclaimed asphalt containing PMB and economic implications of their use. It is found that pavement performance of surfacing mixtures with reclaimed asphalt containing PMB is significantly better for plastic deformation at the cost of earlier initiation and progression of surface distress due to cracking and potholing. This paper suggests that due to cracking and potholing, periodic maintenance costs increase for pavements with reclaimed asphalt material containing PMB; however, they are outweighed by lower procurement cost and longer life expectancy due to slower plastic deformation of the pavement.

Pavement Performance of Hot In-Place Recycling for Waste Asphalt Mixtures

2013 ◽  
Vol 668 ◽  
pp. 292-296
Author(s):  
Ya Li Ye ◽  
Chuan Yi Zhuang ◽  
Jia Bo Hu
Keyword(s):  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Asphalt Pavements ◽  
Pavement Performance ◽  
Test Results ◽  
Technical Parameters ◽  
Stable Performance ◽  
Wheel Tracking Test ◽  
Asphalt Content ◽  
Wheel Tracking

With the early asphalt pavements have been into the stage of medium maintenance or overhaul, recycling is a very important way for waste asphalt mixtures. A sample was taken in the expressway from Huhhot to Baotou, and the waste mixtures were extracted from field and sieved; so that the new aggregates can be determined and mix design was carried. With the aid of the penetration, the softening point and the viscosity in 135°C test, the quantity of the regenerant and the asphalt content were ascertained. Through the high temperature stable performance, the anti-low temperature performance, the water stability and the Hamburg wheel-tracking test, the appropriate gradation and the optimum asphalt content were determined. The test results showed that the pavement performance of the waste asphalt mixture was enhanced obviously with hot in-place recycling, and it has achieved technical parameters for old asphalt mixture.

Effect of Cold Storage on Mechanical Properties of Aorta

2015 ◽  
Author(s):  
Shijia Zhao ◽  
John Lof ◽  
Shelby Kutty ◽  
Linxia Gu
Keyword(s):  
Mechanical Properties ◽  
Uniaxial Tension ◽  
Cold Storage ◽  
Elastic Moduli ◽  
Heart Diseases ◽  
Axial Direction ◽  
Circumferential Direction ◽  
Control Group ◽  
Aortic Tissue ◽  
Tension Tests

Aortic allografts have been widely used in treatments of congenital heart diseases with satisfactory clinical outcomes. They were usually cryopreserved and stored for surgical use. The objective of this work was to investigate the effect of cold storage on mechanical properties of aorta, since the compliance mismatch was one important factor associated with the complication after graft surgery. The segments of porcine descending aorta were divided into two groups: the fresh samples which were tested within 24 hours after harvesting served as control group, and frozen samples which were stored in −20°C for 7 days and then thawed. The uniaxial tension tests along circumferential direction and indentation tests were conducted. The average incremental elastic moduli within each stretch range were obtained from the experimental data obtained during tension tests, and the elastic moduli were also calculated by fitting the force-indentation depth data to Hertz model when the tissue was stretched at 1.0, 1.2, 1.4 and 1.6. In addition, the average incremental elastic moduli of both fresh and frozen aortic tissue along axial direction were also obtained by using uniaxial tension tests. The comparison showed that cold storage definitely increased the average incremental elastic modulus of the aortic tissue along circumferential direction; however, the difference is not significant for the elastic moduli along axial direction.

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