scholarly journals Intelligent composites and their use for self-healing concrete

2019 ◽  
Vol 6 (4) ◽  
Author(s):  
Vladimir Erofeev ◽  
Valeriy Kruglov ◽  
Nikolay Vatin ◽  
Salman Dawood Salman Al-Dulaimi

It is shown that during operation reinforced concrete structures are very often susceptible to cracking, which leads to a deterioration in the quality and expected life of them. The traditional methods of restoration and strengthening of structures are methods of building up, impregnating the structure of concrete with polymer and other materials, applying monolithic coatings or gluing metal polymer and other elements. Known repair methods are characterized by high complexity of execution, high cost, etc. It is shown that there is a pressing economic incentive for the development of concrete capable of self-repairing and repairing damage. Recently, tendencies toward the creation of new materials that are capable of actively interacting with external factors have been outlined towards world practice; such materials have received the name “intellectual”. The use of «intelligent» materials allows you to monitor and predict the state of various structures and structures, at the required time and even in hard-to-reach areas, significantly increase the resource of engineering systems and their reliability. It has been shown that to date, various chemical methods have been developed for creating self-healing concrete. One of the breakthrough technologies in the field of obtaining effective materials and structures based on them are biotechnologies based on the use of microorganisms. Many researchers have studied the use of calcite produced by bacteria to increase the life of concrete-based structures and restore buildings by eliminating cracks, increasing the strength of concrete, reducing permeability, and reducing water absorption. The article provides an overview of the work of foreign specialists in these areas.

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1760
Author(s):  
Rose K. Baimuratova ◽  
Gulzhian I. Dzhardimalieva ◽  
Evgeniy V. Vaganov ◽  
Valentina A. Lesnichaya ◽  
Gulsara D. Kugabaeva ◽  
...  

We report here our successful attempt to obtain self-healing supramolecular hydrogels with new metal-containing monomers (MCMs) with pendent 4-phenyl-2,2′:6′,2″-terpyridine metal complexes as reversible moieties by free radical copolymerization of MCMs with vinyl monomers, such as acrylic acid and acrylamide. The resulting metal-polymer hydrogels demonstrate a developed system of hydrogen, coordination and electron-complementary π–π stacking interactions, which play a critical role in achieving self-healing. Kinetic data show that the addition of a third metal-containing comonomer to the system decreases the initial polymerization rate, which is due to the specific effect of the metal group located in close proximity of the active center on the growth of radicals.


2018 ◽  
Vol 761 ◽  
pp. 127-130
Author(s):  
Martina Šomodíková ◽  
Břetislav Teplý ◽  
Dita Vořechovská

The assessment of service life of a structure can be performed via mathematical modelling – either analytical or numerical and it can be viewed as a necessary pre-requisite for life-cycle engineering decisions. Many works concerning the modelling and testing of degradation effects for engineering systems are reported in the literature. The present paper discusses the degradation modelling of reinforced concrete structures and concentrates on the damage they sustain due to chloride ingress, namely a special aspect: the influence of statistical correlation among input variables on the reliability.


Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3782
Author(s):  
Anupama Devi V. K. ◽  
Rohin Shyam ◽  
Arunkumar Palaniappan ◽  
Amit Kumar Jaiswal ◽  
Tae-Hwan Oh ◽  
...  

Polymeric hydrogels are widely explored materials for biomedical applications. However, they have inherent limitations like poor resistance to stimuli and low mechanical strength. This drawback of hydrogels gave rise to ‘’smart self-healing hydrogels’’ which autonomously repair themselves when ruptured or traumatized. It is superior in terms of durability and stability due to its capacity to reform its shape, injectability, and stretchability thereby regaining back the original mechanical property. This review focuses on various self-healing mechanisms (covalent and non-covalent interactions) of these hydrogels, methods used to evaluate their self-healing properties, and their applications in wound healing, drug delivery, cell encapsulation, and tissue engineering systems. Furthermore, composite materials are used to enhance the hydrogel’s mechanical properties. Hence, findings of research with various composite materials are briefly discussed in order to emphasize the healing capacity of such hydrogels. Additionally, various methods to evaluate the self-healing properties of hydrogels and their recent advancements towards 3D bioprinting are also reviewed. The review is concluded by proposing several pertinent challenges encountered at present as well as some prominent future perspectives.


Author(s):  
Dawei Sun ◽  
◽  
Jianhua Yan ◽  
Xiaoyu Ma ◽  
Mingzhang Lan ◽  
...  
Keyword(s):  

Proceedings ◽  
2019 ◽  
Vol 34 (1) ◽  
pp. 20
Author(s):  
Lenting ◽  
Orlowsky

Sustainable maintenance of existing steel-reinforced concrete structures becomes more important. Using non-reinforced sprayed mortar to maintain these structures often leads to cracks in this repair layer due to the alteration of crack widths in the ordinary structure. The water impermeability as well as the durability of the sprayed mortar will be reduced due to the described cracks. This presentation shows a solution for the described problem. The use of carbon yarns with a special inorganic coating as reinforcement in sprayed mortars leads to a self-healing of the arising cracks. Due to the inorganic coating applied on carbon yarns the excellent bond between mortar and yarn results in a fine distributed crack image with crack width below 0.1 mm. It is shown that these cracks heal themselves. Consequently we can provide a mainly mineral protection layer for existing steel reinforced concrete structures which is impermeably to water based solutions. The presentation focuses on the material development and characterization.


2019 ◽  
Vol 91 ◽  
pp. 02048
Author(s):  
Elena Korneeva ◽  
Anna Babanina ◽  
Yulia Larionova

Natural limestone is subjected to negative impact of external factors, such as rain and low air temperature. One of the ways to improve the properties of limestone is considered in the paper, which is its treatment with Oxal NK100 compound. A review of the literature regarding the problem of durability and the use of limestone is presented. The water absorption and freeze-thaw resistance of the rock was determined experimentally before and after processing with a stone reinforcing compound. The analysis of the obtained data is conducted and conclusions about the effectiveness of the Oxal NK100 composition are drawn.


2019 ◽  
Author(s):  
Marco Carini ◽  
Mauro Marongiu ◽  
Karol Strutyński ◽  
Akinori Saeki ◽  
Manuel Melle-Franco ◽  
...  

<div><div><div><p>Supramolecular polymers have a lot of potential in the development of new materials because of their inherent recyclability and their self-healing and stimuli-responsive properties. Supramolecular conductive polymers are generally obtained by the assembly of individual disk-like π-conjugated molecules into columnar arrays that provide an optimal channel for electronic transport. We report a new approach to prepare supramolecular polymers by hooking together sigmoidal monomers into 1D arrays of π-stacked anthracene and acridine units, which give rise to micrometer-sized fibrils that show pseudoconductivities in line with other conducting materials. This approach paves the way for the design of new supramolecular polymers constituted by acene derivatives with enhanced excitonic and electronic transporting properties.</p></div></div></div>


2013 ◽  
Vol 409-410 ◽  
pp. 355-361
Author(s):  
Ámos Dufka ◽  
Lenka Mészárosová ◽  
Jana Kosíková

The experience in building practice proves that in assessing and evaluating the state of reinforced concrete structures, also professional companies place a clear emphasis mainly on determining the strength characteristics of concrete, assessing the rate of corrosion and the distribution of reinforcements in assessed elements. Obtaining these data is essential for the structural analysis of a structure. However, from the view of a complex evaluation of the state of structures, this information is quite insufficient, for example because of fully omitting the evaluation of the state or rate of degradation of concrete by action of chemically aggressive substances from the outside environment. For example, it is not possible to predict further life of a structure in a relevant manner on the basis of facts only found out by testing the strength characteristics of concrete.


2012 ◽  
Vol 2 (2) ◽  
Author(s):  
Regina Frei ◽  
Giovanna Marzo Serugendo

AbstractComplexity Engineering encompasses a set of approaches to engineering systems which are typically composed of various interacting entities often exhibiting self-* behaviours and emergence. The engineer or designer uses methods that benefit from the findings of complexity science and often considerably differ from the classical engineering approach of “divide and conquer”.This article provides an overview on some very interdisciplinary and innovative research areas and projects in the field of Complexity Engineering, including synthetic biology, chemistry, artificial life, self-healing materials and others. It then classifies the presented work according to five types of nature-inspired technology, namely: (1) using technology to understand nature, (2) nature-inspiration for technology, (3) using technology on natural systems, (4) using biotechnology methods in software engineering, and (5) using technology to model nature. Finally, future trends in Complexity Engineering are indicated and related risks are discussed.


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