In ‘3D printed capsules for self-healing concrete applications,’ researchers are exploring the world of self-healing materials further, with the creation of macro-capsules that can actually be filled with a variety of different agents to repair defects like cracking in concrete. For this study, they 3D printed tubular capsules and then filled them with two different types of chemicals—either polyurethane resin or liquid sodium silicate.
The approach shows promise, and it makes sense. The capsules (either micro- or macro-) break upon contact with a defect and then repair it. Previous research has examined encapsulation techniques—and some have been successful. Other researchers have created:
- Hollowed glass tubes
- Ceramic tubes produced by phase-inversion spinning
- Cementitious capsules produced by extrusion
- Polymeric capsules produced by extrusions
For this study, a Prusa I3 Hephestos 3D printer was used, set up with a 0.40 mm diameter nozzle. The team tried four different materials:
The researchers evaluated whether the sample capsules were watertight, as this was a subject of ‘paramount importance’ for effective self-healing capsules. They tried filling the capsules with water, and then offered numerous variations, such as coated, not coated, without sealed ends, and more.
“Except in the case of PLA, the application of the external coating resulted in an overall reduction of the water absorption rate and an increased repeatability in the results, as in the case of the PET and PETG where the results were significantly different and most likely governed by the printing and layer adhesion defects,” stated the researchers.
The team then began to investigate the reaction of the capsules to a ‘harsh cementitious environment.’ With the Model 1 capsules, the sodium silicate was still viable for self-healing. Model 2 capsules were tested as the team evaluated the water loss over time, which was visible.
“Both models, when filled with the healing agents suitable for their characteristic features, showed satisfactory results in terms of mechanical recovery and spreading of the healing agent on the crack faces,” concluded the researchers. “This last feature suggests a good self-sealing ability, which is very important for preventing the ingress of harmful substances inside the fractured matrix. This aspect will be further investigated through tests aimed to assess self-sealing and durability-related features, such as water permeability and absorption tests.
“These positive results show a good potential of the proposed capsule-based system for structural applications. This work served as proof of concept of the use of Additive Manufacturing to produce self-healing encapsulated system, by using simple tubular capsules for the sake of comparison of extensively investigated system. Further improvements can be envisaged through the optimization of the capsule shape, for which the 3D printing technology offers virtually unlimited tailoring possibilities.”
Our world continues to grow smarter day by day, and often in the most surprising of places. While electronics (and especially robotics) are a logical area for smart devices, many others are up and coming, to include 4D printed materials which can morph according to their environment. Self-healing materials are another interesting element also, from materials that can fix shoes that are wearing out, to gel, and other self-healing structures. What do you think of this news? Let us know your thoughts! Join the discussion of this and other 3D printing topics at 3DPrintBoard.com.[Source / Images: 3D printed capsules for self-healing concrete applications]
You May Also Like
Multimaterial 3D Printing Filaments for Optoelectronics
Authors Gabriel Loke, Rodger Yuan, Michael Rein, Tural Khudiyev, Yash Jain, John Joannopoulous, and Yoel Fink have all come together to explore new filament options, with their findings outlined in...
Germany: Two-Photon Polymerization 3D Printing with a Microchip Laser
Laser additive manufacturing technology is growing more prevalent around the world for industrial uses, leading researchers to investigate further in relation to polymerization, with findings outlined in the recently published...
3D Printing Polymer-Bonded Magnets Rival Conventional Counterparts
Authors Alan Shen, Xiaoguang Peng, Callum P. Bailey, Sameh Dardona, and W.K Anson explore new techniques in ‘3Dprinting of polymer-bonded magnets from highly concentrated, plate-like particle suspension.’ While magnets have...
South Africa: FEA & Compression Testing of 3D Printed Models
Researchers D.W. Abbot, D.V.V. Kallon, C. Anghel, and P. Dube delve into complex analysis and testing in the ‘Finite Element Analysis of 3D Printed Model via Compression Tests.’ For this...
View our broad assortment of in house and third party products.