scholarly journals Evaluation air void content of drilled porous asphalt mixture cores using non-destructive X-ray computed tomography

2021 ◽  
pp. 48-58
Author(s):  
T. Vieira ◽  
J. Lundberg ◽  
O. Eriksson ◽  
A. Guarin ◽  
S. Gong ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Asphalt Mixture ◽  
Void Content ◽  
Porous Asphalt ◽  
X Ray ◽  
X Ray Computed ◽  
Air Void ◽  
Non Destructive ◽  
Air Void Content

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.

scholarly journals Dynamic Modulus of Porous Asphalt and the Effect of Moisture Conditioning

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1230 ◽  
Author(s):  
Tan Hung Nguyen ◽  
Jaehun Ahn ◽  
Jaejun Lee ◽  
Jin-Hwan Kim
Keyword(s):  
Dynamic Modulus ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Void Content ◽  
Water Tank ◽  
Porous Asphalt ◽  
Air Void ◽  
Frequent Exposure ◽  
Air Void Content ◽  
Selection Of

Porous asphalt has been used for permeable pavement to improve safety of roadways and the effectiveness of storm water management. As a surface drainage layer with frequent exposure to water, this material is affected by moisture. In this study, dynamic modulus tests were performed on both moisture unconditioned and conditioned specimens to characterize viscoelastic properties of porous asphalt mixture. The dynamic modulus values of porous asphalt materials with air void content of 9.0% and 20.5% were investigated at dry condition and after specified moisture conditioning cycles. One cycle of moisture conditioning procedure included placing specimens in water tank at 60 °C for 24 h, and then in another water tank at 25 °C for additional 2 h. The results showed that porous asphalt mixture with lower air void content resulted in higher values of dynamic modulus, and these values of porous asphalt with air void content of 9.0% was about 1.5 to 3.0 times that of porous asphalt with air void content of 20.5%. Higher value of the first number of performance graded binder (average 7-day maximum pavement design temperature) seems to make the dynamic modulus values at high temperatures larger. After moisture conditioning, the dynamic modulus of porous asphalt mixture increased, overall, especially at low temperatures. The appropriated selection of asphalt binder, a weakening of asphalt due to moisture damage can be reduced.

scholarly journals Study on Void Structure Reconstruction of Asphalt Mixture by X-Ray Computed Tomography and Otsu’s Method

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Jiantong Zhang ◽  
Jun Yang ◽  
Tiejun Liu ◽  
Rongxing Cai ◽  
Rui Yang
Keyword(s):  
Computed Tomography ◽  
Asphalt Mixture ◽  
Accurate Estimate ◽  
Asphalt Mixtures ◽  
Air Voids ◽  
X Ray ◽  
Sample Depth ◽  
Otsu’S Method ◽  
X Ray Computed ◽  
Air Void

The purpose of this paper is to obtain the pore distribution of asphalt mixture accurately by nondestructive technology. Specimens prepared with four gradations of asphalt mixtures were scanned using X-ray computed tomography (CT) which was used to measure air void sizes at different depths within specimens. The air void distributions of obtained CT images were analyzed using ring blocking segmentation combining Otsu’s method, which provided an accurate estimate of air voids in asphalt mixtures. The image processing results showed that air void distribution was not uniform in the specimens; higher air void concentrations were found at the top and bottom of the specimen, and lower, in the rest of the sample depth. The air void sizes of SUP13 and AC13 are mainly distributed between 0.15 to 0.2 mm, while PA13 and SMA13 are 0.4 to 0.65 mm and 0.4 to 0.7 mm, respectively. It is believed that the CT pictures processed by the ring blocking segmentation combining Otsu’s method is feasible and rational to capture the air voids size and content of asphalt mixtures.+

scholarly journals Moisture Susceptibility of Warm Mix Asphalt (WMA) with an Organic Wax Additive Based on X-Ray Computed Tomography (CT) Technology

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Jie Ji ◽  
Hui Yao ◽  
Zhikai Yuan ◽  
Zhi Suo ◽  
Ying Xu ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Moisture Content ◽  
Void Content ◽  
Moisture Susceptibility ◽  
Air Voids ◽  
X Ray ◽  
X Ray Computed ◽  
Indirect Tensile ◽  
Air Void ◽  
Air Void Content

The warm mix asphalt was fabricated with different moisture contents (0%, 1%, 2%, and 3%) of limestone aggregates using the Superpave gyratory compactor. The moisture susceptibility of asphalt mixtures with an organic wax additive RH was studied. The samples were compacted and tested using the modified Lottman test AASHTO T283, and the X-ray computed tomography technology was used to capture the internal structure images before and after the freeze-thaw cycles. The test results show that the air voids were distributed in the size range of 0–5 mm3 and 5–10 mm3. The number of air voids decreased with the increase of air void size and increased after freeze-thaw cycles. The air void content can be influenced by the residual moisture in aggregates. The higher the moisture content of aggregates is, the larger the air void content is. So, the air void content is likely to be sensitive to moisture damage. The increase ratio of the air void and moisture content of aggregates had good correlation with the indirect tensile strength and tensile strength ratio of the samples. The indirect tensile strength and tensile strength ratio of the samples decreased linearly, and the samples were sensitive to the moisture damage with the increases of increase ratio of the air void/moisture content in aggregates.

scholarly journals Non-destructive characterization of additively manufactured components with x-ray computed tomography for part qualification: A study with laboratory and synchrotron x-rays

2021 ◽  
Vol 173 ◽  
pp. 110894
Author(s):  
Ercan Cakmak ◽  
Philip Bingham ◽  
Ross W. Cunningham ◽  
Anthony D. Rollett ◽  
Xianghui Xiao ◽  
...  
Keyword(s):  
Computed Tomography ◽  
X Rays ◽  
X Ray ◽  
X Ray Computed ◽  
Non Destructive ◽  
Non Destructive Characterization

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.

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