Electrical, Thermal and Induction Heating Properties of Dense Asphalt Concrete

2013 ◽  
Vol 723 ◽  
pp. 303-311 ◽  
Author(s):  
Alvaro Garcia ◽  
Jose Norambuena-Contreras ◽  
Manfred N. Partl
Keyword(s):  
Induction Heating ◽  
Asphalt Concrete ◽  
Asphalt Mixture ◽  
Void Content ◽  
Steel Wool ◽  
Electrically Conductive ◽  
Wool Fibers ◽  
Conductive Fibers ◽  
Different Diameters ◽  
Air Void

Induction heating consists in adding electrically conductive fibers to the asphalt mixture and heating them with an induction heating device. But still, the factors that affect the increase of temperature are not well-known. With this purpose, 25 different mixtures, with the same aggregates distribution and amount of bitumen, but with 2 different lengths, 4 different quantities, and 4 different diameters of steel wool fibers have been considered. The influence of fibers on the air void content, electrical and thermal conductivity and on the induction heating of dense asphalt concrete has been studied. It was found that steel wool fibers increase slightly the electrical and thermal conductivities of dense asphalt concrete. Finally, it has been observed that the temperature reached due to the induction heating, increases with the number of fibers in the mixture and with their diameter.

Effect of steel wool fibers on mechanical and induction heating response of conductive asphalt concrete

2019 ◽  
Vol 21 (14) ◽  
pp. 1755-1768 ◽  
Author(s):  
Mohammad M. Karimi ◽  
Masoud K. Darabi ◽  
H. Jahanbakhsh ◽  
Behnam Jahangiri ◽  
John F. Rushing
Keyword(s):  
Induction Heating ◽  
Asphalt Concrete ◽  
Steel Wool ◽  
Wool Fibers

scholarly journals Study of High-Temperature Properties of Asphalt Mixtures Used for Bridge Pavement with Concrete Deck

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4238
Author(s):  
Piotr Pokorski ◽  
Piotr Radziszewski ◽  
Michał Sarnowski
Keyword(s):  
Permanent Deformation ◽  
Asphalt Mixture ◽  
Binder Content ◽  
Void Content ◽  
Concrete Bridge ◽  
Asphalt Mixes ◽  
Protective Layers ◽  
Concrete Bridge Decks ◽  
Air Void ◽  
Air Void Content

The paper presents the issue of resistance to permanent deformations of bridge pavements placed upon concrete bridge decks. In Europe, bridge asphalt pavement usually consists of a wearing course and a protective layer, which are placed over the insulation (waterproofing). Protective layers of bridge pavement are commonly constructed using low air void content asphalt mixes as this provides the suitable tightness of such layers. Due to increased binder content, asphalt mixes for bridge pavement may have reduced resistance to permanent deformations. The article presents test results of resistance to permanent deformations of asphalt mixes for the protective layers. In order to determine the composition of mixtures with low air void content and resistance to permanent deformation, an experimental design was applied using a new concept of asphalt mix composition. Twenty-seven different asphalt mixture compositions were analyzed. The mixtures varied in terms of binder content, sand content and grit ratio. Resistance to permanent deformation was tested using the laboratory uniaxial cyclic compression method (dynamic load creep). On the basis of experimental results and statistical analysis, the functions of asphalt mixture permanent deformation resistance were established. This enabled a determination of suitable mixture compositions for protective layers for concrete bridge decks.

Image processing procedure to quantify the internal structure of porous asphalt concrete

2019 ◽  
Vol 15 (1) ◽  
pp. 206-226 ◽  
Author(s):  
Kabiru Abdullahi Ahmad ◽  
Norhidayah Abdul Hassan ◽  
Mohd Ezree Abdullah ◽  
Munder A.M. Bilema ◽  
Nura Usman ◽  
...  
Keyword(s):  
Internal Structure ◽  
Asphalt Concrete ◽  
Functional Performance ◽  
Resilient Modulus ◽  
Asphalt Mixture ◽  
Content Type ◽  
Porous Asphalt ◽  
X Ray ◽  
Air Void ◽  
Aggregate Interlock

Purpose In order to fully understand the properties of porous asphalt, investigation should be conducted from different point of views. This is from the fact that porous asphalt mixture designed with the same aggregate gradation and air void content can give different infiltration rate due to the different formation of the internal structure. Therefore, the purpose of this paper is to investigate the micro-structural properties and functional performance of porous asphalt simultaneously. Design/methodology/approach The aim is to develop imaging techniques to process and analyze the internal structure of porous asphalt mixture. A few parameters were established to analyze the air void properties and aggregate interlock within the gyratory compacted samples captured using a non-destructive scanning technique of X-ray computed tomography (CT) throughout the samples. The results were then compared with the functional performance in terms of permeability. Four aggregate gradations used in different countries, i.e. Malaysia, Australia, the USA and Singapore. The samples were tested for resilient modulus and permeability. Quantitative analysis of the microstructure was used to establish the relationships between the air void properties and aggregate interlock and the resilient modulus and permeability. Findings Based on the results, it was found that the micro-structural properties investigated have successfully described the internal structure formation and they reflect the results of resilient modulus and permeability. In addition, the imaging technique which includes the image processing and image analysis for internal structure quantification seems to be very useful and perform well with the X-ray CT images based on the reliable results obtained from the analysis. Research limitations/implications In this study, attention was limited to the study of internal structure of porous asphalt samples prepared in the laboratory using X-ray CT but can also be used to assess the quality of finished asphalt pavements by taking core samples for quantitative and qualitative analysis. The use of CT for material characterization presents a lot of possibilities in the future of asphalt concrete mix design. Originality/value Based on the validation process which includes comparisons between the values obtained from the image analysis and those from the performance test and it was found that the developed procedure satisfactorily assesses the air voids distribution and the aggregate interlock for this reason, it can be used.

Induction heating of electrically conductive porous asphalt concrete

2010 ◽  
Vol 24 (7) ◽  
pp. 1207-1213 ◽  
Author(s):  
Quantao Liu ◽  
Erik Schlangen ◽  
Álvaro García ◽  
Martin van de Ven
Keyword(s):  
Induction Heating ◽  
Asphalt Concrete ◽  
Electrically Conductive ◽  
Porous Asphalt ◽  
Porous Asphalt Concrete

Specimen Geometry Study for Direct Tension Test Based on Mechanical Tests and Air Void Variation in Asphalt Concrete Specimens Compacted by Superpave Gyratory Compactor

2000 ◽  
Vol 1723 (1) ◽  
pp. 125-132 ◽  
Author(s):  
Ghassan R. Chehab ◽  
Emily O’Quinn ◽  
Y. Richard Kim
Keyword(s):  
Asphalt Concrete ◽  
Tensile Testing ◽  
Complex Modulus ◽  
Specimen Geometry ◽  
Uniaxial Tensile ◽  
Void Content ◽  
Uniaxial Tensile Testing ◽  
Superpave Gyratory Compactor ◽  
Air Void ◽  
Air Void Content

Reliable materials characterization and performance prediction testing of asphalt concrete requires specimens that can be treated as statistically homogeneous and representative of the material being tested. The objective of this study was to select a proper specimen geometry that could be used for uniaxial tensile testing. Selection was based on the variation of air void content along the height of specimens cut and cored from specimens compacted by the Superpave gyratory compactor (SGC) and on the representative behavior under mechanical testing. From measurement and comparison of air void contents in cut and cored specimens, it was observed for several geometries that sections at the top and bottom and those adjacent to the mold walls have a higher air void content than do those in the middle. It is thus imperative that test specimens be cut and cored from larger-size SGC specimens. Complex modulus and constant crosshead-rate monotonic tests were conducted for four geometries—75 × 115, 75 × 150, 100 × 150, and 100 × 200 mm—to study the effect of geometry boundary conditions on responses. On the basis of graphical and statistical analysis, it was determined that there was an effect on the dynamic modulus at certain frequencies but no effect on the phase angle. Except for 75 × 115 mm, all geometries behaved similarly under the monotonic test. From these findings and other considerations, it is recommended that the 75- × 150-mm geometry, which is more conservative, and the 100- × 150-mm geometry be used for tensile testing.

Study on Volume Performance of Conductive Asphalt Concrete Based on Freeze-Thaw Cycle

2013 ◽  
Vol 303-306 ◽  
pp. 2501-2504 ◽  
Author(s):  
Pan Pan ◽  
Chang Jun Sun ◽  
Ning Tang ◽  
Ming Yu Chen ◽  
Shao Peng Wu
Keyword(s):  
Asphalt Concrete ◽  
Asphalt Mixture ◽  
Material Composition ◽  
Moisture Resistance ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Volume Properties ◽  
Freeze Thaw Cycle ◽  
Air Void ◽  
Weight Loss Ratio

Conductive asphalt concrete, a kind of intelligent materials, can serve as asphalt solar collector, asphalt heater and self monitor. And moisture damage is one of the most common performance degradation of asphalt concrete. This paper investigates the volume properties of conductive asphalt concrete based on Freeze-thaw cycles. Marshall specimen was frozen and thawed repeatedly and a cycle consists 16h at -18oC and 8h at 60oC. The change of air void and weight loss ratio were chosen to evaluate the moisture resistance of conductive asphalt concrete. Three types of asphalt mixture (control, CAC 1 and CAC 2) were used to study the effect of initial void and material composition on moisture resistance. The results show that both the framework structures and the material composition have a great effect on antifreeze-thaw property of asphalt concrete, which provides an efficient guidance for application of this technology in pavement.

Application of Limestone Manufactured Sand as Fine Aggregate in Asphalt Concrete

2012 ◽  
Vol 509 ◽  
pp. 123-127
Author(s):  
Shao Peng Wu ◽  
Pei Qiang Cui ◽  
Deng Feng Zhang
Keyword(s):  
Asphalt Concrete ◽  
Asphalt Mixture ◽  
Moisture Damage ◽  
Pavement Performance ◽  
Fine Aggregate ◽  
Replacement Ratio ◽  
Manufactured Sand ◽  
Volume Properties ◽  
Pavement Construction ◽  
Air Void

The property of aggregate has a significant effect on the performance of asphalt mixture because of its high proportion. Asphalt mixture prepared by some kind of aggregate cause the inadequate compaction problem, which results in moisture damage due to its large air void. Limestone manufactured sand is considered as one of the useful solution to overcome the compaction problem. In this paper, fine aggregate is substituted by different proportion of limestone manufactured sand (LMS). The effect of replacement ratio on volume properties and pavement performance is studied. The results show that the limestone manufactured sand can improve the pavement performance and is benefit to the compaction of andesite asphalt mixture. Furthermore, this research also provided some valuable parameters for guiding the pavement construction in the future.

The Effect of Compaction Temperatures and Numbers on the Air Void Level of Porous Asphalt Pavements

2021 ◽  
Author(s):  
Ahmet Buğra İbiş ◽  
Burak Şengöz ◽  
Ali Topal ◽  
Derya Kaya Özdemir
Keyword(s):  
Heavy Traffic ◽  
Experimental Studies ◽  
Asphalt Mixture ◽  
Hollow Structure ◽  
Asphalt Pavements ◽  
Void Content ◽  
Porous Asphalt ◽  
Compaction Energy ◽  
Air Void ◽  
Air Void Content

Porous asphalt pavement is defined as an asphalt concrete that is designed with open gradation aggregate which helps in removing the water with an air void content of about 20% by creating drainage channels. Open gradation consists of large amounts of coarse aggregates and small amounts of fine aggregates. The water is drained due to this hollow structure, this air void content in the porous asphalt mixture which inevitably decreases with time is the main parameter affecting the service life as well as the structural and functional performance. Moreover, the reduction in air void content is one of the main reasons for the loss of permeability in porous asphalt pavements and this lead to the increase in pavement density under heavy traffic conditions. Each country has its own technical asphalt specification involving the required compaction energy and temperature. This study involves the effect of compaction temperatures and numbers on the air void in porous asphalt pavements prepared with 50/70 penetration grade bitumen. As a result of experimental studies, it has been observed that the reduced compaction temperature and the number of compaction (energy) increase the air void level in porous asphalt pavements.

Optimization of the Laboratory Fabrication of Small Specimens for Asphalt Mixture Performance Testing

2018 ◽  
Vol 2672 (28) ◽  
pp. 438-450 ◽  
Author(s):  
Sonja Pape ◽  
Kangjin Lee ◽  
Cassie Castorena ◽  
Y. Richard Kim
Keyword(s):  
Dynamic Modulus ◽  
Fatigue Testing ◽  
Extraction Procedure ◽  
Asphalt Mixture ◽  
Performance Testing ◽  
Cyclic Fatigue ◽  
Fatigue Tests ◽  
Void Content ◽  
Multiple Test ◽  
Air Void

The use of 38-mm-diameter small specimens for uniaxial dynamic modulus and cyclic fatigue asphalt mixture performance testing offers a significant opportunity to improve the efficiency of laboratory-fabricated specimen testing because multiple test specimens can be extracted per Superpave gyratory-compacted (SGC) sample. This study seeks to optimize the procedure used for the extraction of small specimens from SGC samples for dynamic modulus and cyclic fatigue tests. To this end, small cylindrical specimens were cored horizontally and vertically from SGC samples and subjected to performance testing. The dynamic modulus and fatigue test results indicate that the effects of anisotropy are minimal. However, all of the horizontally extracted small specimens exhibited fatigue failure at the specimen ends, outside the range of the gauges; the failure was likely due to the peripheral air void gradients in the SGC samples. Therefore, the authors concluded that small specimens should be vertically cored from SGC samples for the laboratory fabrication of small specimens. Specifically, four small specimens were cored vertically from the inner 100 mm of SGC samples where the air void content is relatively uniform. Four mixtures with different nominal maximum aggregate sizes (NMASs) were used to prepare small specimens using the proposed extraction procedure. These specimens were subjected to dynamic modulus and cyclic fatigue testing. The results demonstrate an increase in specimen-to-specimen variability with an increase in NMAS, which also is expected in large specimen testing.

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