scholarly journals Investigation of the Potential Use of Calcium Alginate Capsules for Self-Healing in Porous Asphalt Concrete

Materials ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 168 ◽  
Author(s):  
Shi Xu ◽  
Xueyan Liu ◽  
Amir Tabaković ◽  
Erik Schlangen
Keyword(s):  
Asphalt Concrete ◽  
Calcium Alginate ◽  
Self Healing ◽  
Stiffness Modulus ◽  
Porous Asphalt ◽  
Alginate Capsules ◽  
Asphalt Mix ◽  
X Ray Computed ◽  
Indirect Tensile ◽  
Porous Asphalt Concrete

Improving the healing capacity of asphalt is proving to be an effective method to prolong the service life of an asphalt pavement. The calcium alginate capsules encapsulating rejuvenator have been developed and proved to provide successful localized crack healing in asphalt mastic. However, it is not known whether this self-healing asphalt system will improve healing capacity of a full asphalt mix. To this aim, this paper reports on study which investigate effect of the calcium alginate capsules onto self-healing capacity of the porous asphalt mix. X-ray computed tomography (XCT) was used to visualize the distribution of the capsules in porous asphalt. The effect of the capsules on fracture resistance of porous asphalt concrete was studied by semi-circular bending (SCB) tests. A semi-circular bending and healing programme was carried out to evaluate the healing effect of these capsules in porous asphalt concrete. Indirect Tensile Stiffness Modulus (ITSM) tests were employed in order to investigate the influence of the capsules on the stiffness of the porous asphalt concrete. The results indicate that incorporating calcium alginate capsules significantly improve the healing capacity of porous asphalt concrete without compromising its performance.

scholarly journals The influence of asphalt ageing on induction healing effect on porous asphalt concrete

2019 ◽  
Vol 3 ◽  
pp. 98-103 ◽  
Author(s):  
Shi Xu ◽  
Xueyan Liu ◽  
Amir Tabaković ◽  
Erik Schlangen
Keyword(s):  
Asphalt Concrete ◽  
Induction Machine ◽  
The Self ◽  
Electromagnetic Current ◽  
Self Healing ◽  
Porous Asphalt ◽  
Healing Effect ◽  
Healing Efficiency ◽  
Concrete Mix ◽  
Porous Asphalt Concrete

Induction healing is a proven technology which is able to improve the self-healing capacity of asphalt concrete. Healing is achieved via electromagnetic current produced by passing induction machine, where steel asphalt constituents heat up which in turn soften the bitumen in the asphalt layer, allowing it to flow and close cracks, repairing the damage. This paper reports on the study which investigated the influence of ageing on the healing capacity of Porous Asphalt (PA) concrete. Porous Asphalt concrete mix was prepared first,  then subjected to an accelerated (laboratory) ageing process using a ventilated oven. In order to further evaluate the induction healing efficiency of asphalt concrete,  Semi-circular bending (SCB) and healing cycles were performed on asphalt concrete specimens. The results show that with an increase of the ageing level of porous asphalt concrete, the induction healing efficiency decreases.

Effects of Steel Wool Distribution on Properties of Porous Asphalt Concrete

2014 ◽  
Vol 599 ◽  
pp. 150-154 ◽  
Author(s):  
Quan Tao Liu ◽  
Shao Peng Wu
Keyword(s):  
Tensile Strength ◽  
Induction Heating ◽  
Asphalt Concrete ◽  
Mixing Time ◽  
Ct Scanning ◽  
Indirect Tensile Strength ◽  
Steel Wool ◽  
Porous Asphalt ◽  
Indirect Tensile ◽  
Porous Asphalt Concrete

An unravelling porous asphalt concrete was developed by adding steel wool and heating it with induction energy. The purpose of this paper is to examine the effects of the steel wool distribution on the properties of this unravelling porous asphalt concrete. The mixture was mixed for 10 min, 12 min, 15 min or 20 min respectively, and then samples were prepared with a gyratory compactor. The steel wool distribution at different mixing time was compared with CT scanning analysis. The electrical resistance, indirect tensile strength and induction heating speed of samples with different mixing time were also studied. It was found that a better distribution of steel wool in porous asphalt concrete increased its indirect tensile strength, but decreased its electrical conductivity and induction heating speed. 15 min mixing is sufficient to disperse steel wool to a homogenous distribution.

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.

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 Optimization of the Calcium Alginate Capsules for Self-Healing Asphalt

2019 ◽  
Vol 9 (3) ◽  
pp. 468 ◽  
Author(s):  
Shi Xu ◽  
Amir Tabaković ◽  
Xueyan Liu ◽  
Damian Palin ◽  
Erik Schlangen
Keyword(s):  
Calcium Alginate ◽  
Mechanical Response ◽  
Asphalt Mixture ◽  
Environmental Scanning ◽  
Self Healing ◽  
R Ratio ◽  
Capsule Shell ◽  
Alginate Capsules ◽  
Asphalt Mix ◽  
Healing Agent

It has been demonstrated that calcium alginate capsules can be used as an asphalt healing system by pre-placing rejuvenator (healing agent) into the asphalt mix and releasing the rejuvenator on demand (upon cracking). This healing mechanism relies on the properties of capsules which are determined by the capsule preparation process. In this study, to optimize the calcium alginate capsules, capsules are prepared using varying Alginate/Rejuvenator (A/R) ratios. Light microscope microscopy and Environmental Scanning Electron Microscope (ESEM) are employed to characterize the morphology and microstructure of these capsules. Thermal stability and mechanical property are investigated by thermogravimetric analysis (TGA) and compressive tests. The testing results indicate that higher alginate content results in smaller diameter and lower thermal resistance, but higher compressive strength. The optimum A/R ratio of calcium alginate capsules is found to be 30/70. To prove the effectiveness of the optimized capsules, the capsules are embedded in asphalt mortar beams and a bending and healing program is carried out. The effect of capsule shell material on the mechanical response of asphalt mixture is evaluated through three-point bending on the mortar beams embedded with blank capsules (without the healing agent). Aged mortar beams containing alginate capsules encapsulating rejuvenator demonstrate a higher strength recovery after bending tests, which indicates effective healing due to the release of the rejuvenators from the capsules.

Thermal and Mechanical Properties of Calcium Alginate Capsules for Self-Healing Asphalt Concrete

2021 ◽  
Vol 1041 ◽  
pp. 101-106
Author(s):  
Sergey Inozemtcev ◽  
Evgeniy Korolev ◽  
Toan Do Trong
Keyword(s):  
Mechanical Properties ◽  
Asphalt Concrete ◽  
Calcium Alginate ◽  
Breaking Load ◽  
Self Healing ◽  
Thermal And Mechanical Properties ◽  
Strength Index ◽  
Alginate Capsules ◽  
Maximum Decrease ◽  
Loss Of Strength

The key physical and mechanical property is the strength of the capsules, which ensure the implementation of the self-healing technology, in which the capsules are not destroyed during the compaction of the asphalt concrete mixture, but are destroyed during the formation of defects in the asphalt concrete. An increase in the content of the reducing agent in the composition of the alginate emulsion leads to a decrease in the breaking load during compression of the capsules, which is explained by an increase in their diameter. But the change in the content of sodium alginate does not have a significant effect on mechanical properties. As a result of exposure to a temperature of 170 °C, a decrease in the strength of the capsules by 22 % after 1 hour of exposure in the burning oven is observed, and with an increase in the time to 4 hours, the strength decreases by 46.9 %. The maximum decrease in the strength index after 4 hours of exposure at a temperature of 160 °C reaches 29.9 %. A decrease in temperature to 150 °C leads to a decrease in the loss of strength. The strength of the capsules decreases by 4 % after 4 hours of exposure at 150 °C. Exposure of capsules to a temperature of 140 °C has no significant effect on strength.

A STUDY ONTHEWEARINGCHARACTERISTICS OF POROUS ASPHALT CONCRETE

2000 ◽  
Vol 5 ◽  
pp. 96-102
Author(s):  
Satoshi KURODA ◽  
Yoshiteru KATO ◽  
Yasuo GUNJI
Keyword(s):  
Asphalt Concrete ◽  
Porous Asphalt ◽  
Porous Asphalt Concrete
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