Air Void Characterisation in Porous Asphalt Using X-Ray Computed Tomography

2014 ◽  
Vol 911 ◽  
pp. 443-448 ◽  
Author(s):  
Abdul Hassan Norhidayah ◽  
Mohd Zul Hanif Mahmud ◽  
Putra Jaya Ramadhansyah
Keyword(s):  
Computed Tomography ◽  
Aggregate Size ◽  
Size Composition ◽  
Maximum Aggregate Size ◽  
Aggregate Gradation ◽  
Air Voids ◽  
Porous Asphalt ◽  
X Ray ◽  
Specimen Height ◽  
X Ray Computed

This study presents the characterisation of the air voids distribution for porous asphalt mixtures compacted using gyratory compactor. The distribution of voids content and voids shape within the porous asphalt were characterised for different nominal maximum aggregate size (NMAS) and specimen height. This is to evaluate the effect of different aggregate size composition and lift thickness on the air voids characteristics of the compacted porous asphalt. Two types of gradations were adopted i.e. Grading A (with NMAS=10 mm) and Grading B (with NMAS=14 mm) and they were fabricated for two different heights (50 and 100 mm). The internal structure was captured using X-ray Computed Tomography and image analysis techniques were used to process and analyse the images. It was found that mixture with coarse aggregate gradation produced larger void size with an elongated shape, which indicates voids connectivity within the mixture compared to fine gradation with more circular and smaller void size.For lift thickness, itacts differentlyfor different aggregate gradations. The specimen produced greater voids connectivity when the fine and coarse gradations were compacted at 100 mm and 50 mm respectively. These show that NMAS and lift thickness influence the mobility of the aggregate particles during compaction which affect the voids formation and determine the effectiveness of the compaction.

Preliminary Study on X-Ray Computed Tomography to Evaluate Voids in Porous Asphalt Concrete

2012 ◽  
Vol 174-177 ◽  
pp. 345-353 ◽  
Author(s):  
J. D. Lin ◽  
Ming Chin Yeh ◽  
Po Hsun Sung ◽  
R. H. Shiu
Keyword(s):  
Computed Tomography ◽  
Asphalt Concrete ◽  
Mix Design ◽  
Air Voids ◽  
Porous Asphalt ◽  
X Ray ◽  
X Ray Computed ◽  
Preliminary Study ◽  
Porous Asphalt Concrete ◽  
Pore Clogging

The study applies Computed Tomography technology to probe into the porous asphalt concrete and air voids content, and at the same time, try to qualify accessible voids and closed voids and to use the result to evaluate the performance of porous asphalt concrete. The nominal maximum aggregate of this study is 19.0mm. In order to adjust the image of the gray threshold, the void of PAC specimen was obtained by cut-and-try method with the mix design. After scanning through the PAC specimen, the self-innovated software is used to calculate the Va(%), accessible voids and closed voids. After careful calculation, it showed that the accessible voids are about 20.3%, and the closed voids are about 1.15%. Base on the study, it could analyze the effect of pore clogging in PAC with improved the durability and lifetime.

Investigation of concrete workability through characterization of aggregate gradation in hardened concrete using X-ray computed tomography

2019 ◽  
Vol 98 ◽  
pp. 150-161 ◽  
Author(s):  
Ghazal Sokhansefat ◽  
M. Tyler Ley ◽  
Marllon Daniel Cook ◽  
Riyadh Alturki ◽  
Masoud Moradian
Keyword(s):  
Computed Tomography ◽  
Hardened Concrete ◽  
Aggregate Gradation ◽  
X Ray ◽  
X Ray Computed

scholarly journals Drying of Porous Asphalt Concrete Investigated by X-Ray Computed Tomography

2015 ◽  
Vol 69 ◽  
pp. 451-456 ◽  
Author(s):  
I. Jerjen ◽  
L.D. Poulikakos ◽  
M. Plamondon ◽  
Ph. Schuetz ◽  
Th. Luethi ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Asphalt Concrete ◽  
Porous Asphalt ◽  
X Ray ◽  
X Ray Computed ◽  
Porous Asphalt Concrete

scholarly journals The influence of defects at the steel/concrete interface for pitting corrosion initiation studied through X-ray Computed Tomography and image analysis

2019 ◽  
Vol 289 ◽  
pp. 10011
Author(s):  
Emanuele Rossi ◽  
Timo Nijland ◽  
Oğuzhan Çopuroğlu ◽  
Rob Polder ◽  
Branko Šavija
Keyword(s):  
Computed Tomography ◽  
Image Analysis ◽  
Reinforced Concrete ◽  
Pitting Corrosion ◽  
Ct Scans ◽  
Volume Loss ◽  
Air Voids ◽  
X Ray ◽  
X Ray Computed ◽  
Concrete Interface

Although corrosion of reinforcement is a well-known issue for the construction industry, there are still open questions about some fundamentals of corrosion in reinforced concrete. These points include, among others, which are the most sensitive locations of the steel/concrete interface for pitting corrosion to initiate and to propagate. In this study, X-ray computed tomography (CT-scan) is used to characterize eight 20-years-old reinforced concrete cores naturally deteriorated due to chloride-induced corrosion. The volume loss due to corrosion of the reinforcement was quantified through image analysis of CT-scans. The volume loss of the steel was found to be higher for steel rebars embedded in Portland cement specimens rather than in blended cement specimens. Furthermore, CT-scans revealed that the deepest and most frequent corrosion pits, as well as the consequent highest volume loss of steel, were present at the portion of the reinforcement closer to the outdoor environment and in proximity to air voids at the steel/concrete interface. As a consequence, the highest decrease of structural performance of the rebars would be likely localized at those locations. Therefore, the presence of interfacial air voids should be considered as relevant factor when assessing the risk of corrosion of reinforced concrete structures.

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.+

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