MATEC Web of Conferences最新文献_第9页

Time of protection equivalence principle to allow design barrier layers for promoting the use of recycled materials for food contact 保护时间等效原理允许设计屏障层，促进使用可回收材料进行食品接触

MATEC Web of Conferences Pub Date : 2023-01-01 DOI: 10.1051/matecconf/202337906001

Natacha Daoud, C. Breysse, S. Domenek, O. Vitrac

引用次数: 0

Experimental Study of an upflow Fluidized Bed: Identification of Fluidization Regimes 上流流化床的实验研究:流化状态的识别

MATEC Web of Conferences Pub Date : 2023-01-01 DOI: 10.1051/matecconf/202337907005

Ronny Gueguen, Guillaume Sahuquet, S. Mer, A. Toutant, Françoise Bataille, G. Flamant

{"title":"Experimental Study of an upflow Fluidized Bed: Identification of Fluidization Regimes","authors":"Ronny Gueguen, Guillaume Sahuquet, S. Mer, A. Toutant, Françoise Bataille, G. Flamant","doi":"10.1051/matecconf/202337907005","DOIUrl":"https://doi.org/10.1051/matecconf/202337907005","url":null,"abstract":"The concept of solar receiver using fluidized particles as heat transfer fluid is attractive from the point of view of its performance but also of the material used. In this concept, the receiver is composed of tubes subjected to concentrated solar radiation in which the fluidized particles circulate vertically. Circulation in the tubes, immersed in a “nurse” fluidized bed, is ensured thanks to a controlled pressure difference imposed on the latter and secondary aeration. This ventilation located at the bottom of the absorber tubes makes it possible to control the fluidization regimes. The latter strongly influence the parietal heat transfers and therefore the performance of the receiver. In order to better understand the conditions of appearance of these regimes and to better identify them, a study at room temperature was carried out with a tube 45 mm in internal diameter and 3.63 m in height. The tube is instrumented with several pressure sensors distributed over its height. More than 170 experiments have been performed exploring wide ranges of particle and aeration flow rates, with and without particle circulation. Signal processing methods, classically used in the scientific literature of fluidized beds, are applied. Combined together, these methods have enabled the identification of bubbling, pistoning (of the wall and axisymmetric), turbulent fluidization and rapid fluidization regimes. The pooling of all this information allows the establishment of a diagram of the fluidization regimes and their transition, showing that the local slip velocity is the key parameter governing the structure of the flow.","PeriodicalId":18309,"journal":{"name":"MATEC Web of Conferences","volume":"97 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82687371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Large-Scale Laboratory Trials of Self-Healing Technologies 自我修复技术的大规模实验室试验

MATEC Web of Conferences Pub Date : 2023-01-01 DOI: 10.1051/matecconf/202337807004

S. Rengaraju, C. Vlachakis, Vahid Afroughsabet, A. Al-Tabbaa

{"title":"Large-Scale Laboratory Trials of Self-Healing Technologies","authors":"S. Rengaraju, C. Vlachakis, Vahid Afroughsabet, A. Al-Tabbaa","doi":"10.1051/matecconf/202337807004","DOIUrl":"https://doi.org/10.1051/matecconf/202337807004","url":null,"abstract":"Prolonging the life of the reinforced concrete structure is the most promising solution to reduce the carbon emissions from concrete. To achieve that, the structure should be protected from crack formation, which acts as an easy pathway for deleterious agents. Self-healing technologies are intended to provide long-term resilience against cracking due to various deterioration processes. Technologies that performed well in small, laboratory-scale studies are taken to the next level to assess their performance on a larger scale and monitored using various NDT equipment. A 1m long beam with a cross-section (140×120 mm) was cast with two rebars – one with a cover depth of 50 mm from the top and another with a cover depth of 20 mm from the bottom. The mix design consists of CEM IIIA (50 OPC: 50 Slag) cement and 30% lightweight aggregate as a replacement for coarse aggregate. At 28 days of curing, the concrete beams are subjected to accelerated corrosion (by applying a voltage to the bottom rebar) to induce internal cracking. Once internal cracking is induced, the beams are subjected to another 28 days under water for healing. The performance of the beams is monitored via ultrasonic pulse velocity and half-cell potential before and after voltage application. This paper shows the preliminary results and the self-healing efficiency and corrosion resistance of these beams are continuously being monitored under severe chloride conditions to predict the long-term performance.","PeriodicalId":18309,"journal":{"name":"MATEC Web of Conferences","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82564591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

PVDF-based coatings with CNT additions for strain monitoring of mortar substrates subjected to bending 添加碳纳米管的pvdf基涂料用于砂浆基底弯曲应变监测

MATEC Web of Conferences Pub Date : 2023-01-01 DOI: 10.1051/matecconf/202337805001

Gabriele Milone, J. Tulliani, A. Al-Tabbaa

{"title":"PVDF-based coatings with CNT additions for strain monitoring of mortar substrates subjected to bending","authors":"Gabriele Milone, J. Tulliani, A. Al-Tabbaa","doi":"10.1051/matecconf/202337805001","DOIUrl":"https://doi.org/10.1051/matecconf/202337805001","url":null,"abstract":"Sensing coatings are rapidly entering the field of non-destructive tests. While cement-based composites are proving an excellent interaction with new/recent structures, polymer-based coatings, already employed for structural retrofitting purposes, can provide a valuable alternative. This study investigated the production, application, and use of poly(vinylidene fluoride) (PVDF) coatings. A 10w/v% PVDF-to-solvent ratio became the best trade-off between electrical conductivity and bond strength with the substrate. Different concentrations of Carbon Nanotubes (CNT) were investigated: 0.05, 0.10, 0.25, 0.50, and 0.75% by weight of PVDF. The conductive PVDF-CNT composites were brushed on the casted mortar beams with screws embedded as electrodes. The mortar beams and attached polymer coatings were then subjected to bending stress. The Gauge Factor was obtained by comparing the substrate’s strain with the coating’s electric response. The sensing intervals in the Fractional Change of Resistance-strain curves varied in relation to the CNT concentration. For instance, adding 0.50w/v% of CNT gave the highest sensitivity up to 0.2‰ strain, followed by a lower – still sufficient – gauge factor. PVDF-based coatings with CNT additions of 0.25 and 0.75w/v% witnessed a comparable sensing performance in the same strain limits, abruptly increasing and finally stabilizing to a low gauge factor. In contrast, both 0.05 and 0.10w/v% resulted in a low monitoring potential overall. The varying sensing zones experienced by the coating were attributed to the microscopical behavior of CNT within the PVDF matrix. In conclusion, the results highlighted the potentiality of polymeric coatings for sensing, monitoring, and inspection of concrete structures.","PeriodicalId":18309,"journal":{"name":"MATEC Web of Conferences","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82627617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Experimental investigation on the ability of macro-encapsulated polyurethane to resist cyclic damaging actions in self-repaired cement-based elements 宏观包封聚氨酯抗自修复水泥基构件循环损伤能力的实验研究

MATEC Web of Conferences Pub Date : 2023-01-01 DOI: 10.1051/matecconf/202337802016

G. Anglani, J. Tulliani, P. Antonaci

{"title":"Experimental investigation on the ability of macro-encapsulated polyurethane to resist cyclic damaging actions in self-repaired cement-based elements","authors":"G. Anglani, J. Tulliani, P. Antonaci","doi":"10.1051/matecconf/202337802016","DOIUrl":"https://doi.org/10.1051/matecconf/202337802016","url":null,"abstract":"The use of polymer precursors as repairing agents in capsule-based self-healing systems has been extensively studied in recent years. In particular, the effectiveness of macro-encapsulated polyurethane in restoring both watertightness and mechanical properties has been demonstrated at the laboratory level, and the experimental methods to test the effectiveness have been validated following pre-standard procedures. However, the use of macro-capsules containing polyurethane precursors for field applications has not been sufficiently implemented yet. For these systems to become appealing to the construction industry, it is essential to further characterize the self-healing effect in terms of stability in time, namely, to investigate the behavior of the self-healing system when subjected to recurring actions that can affect structures in time, after cracking and subsequent self-repairing. The goal of this study was to characterize the ability of commercial polyurethane foams to withstand cyclic flexural actions and repeated temperature variations after release from cementitious macro-capsules embedded in mortar specimens. The specimens were tested immediately after pre-cracking and self-repairing to characterize the initial sealing efficiency through a water-flow test. The same test was repeated at prescribed time intervals to analyze the evolution of the sealing efficiency with the applied mechanical and thermal stresses. The results showed that the proposed system has good stability against the selected damaging actions and confirmed the potential of encapsulated polyurethane for self-healing applications.","PeriodicalId":18309,"journal":{"name":"MATEC Web of Conferences","volume":"70 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82593025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Development of bio-inspired multi-functional polymeric-based fibers (BioFiber) for advanced delivery of bacterial-based self-healing agent in concrete 用于在混凝土中先进输送细菌基自愈剂的仿生多功能聚合物基纤维(BioFiber)的开发

MATEC Web of Conferences Pub Date : 2023-01-01 DOI: 10.1051/matecconf/202337802001

M. H. Khaneghahi, Divya Kamireddi, Seyed Ali Rahmaninezhad, C. Schauer, Christopher M. Sales, A. Najafi, Aidan Cotton, Amir Sadighi, Y. Farnam

{"title":"Development of bio-inspired multi-functional polymeric-based fibers (BioFiber) for advanced delivery of bacterial-based self-healing agent in concrete","authors":"M. H. Khaneghahi, Divya Kamireddi, Seyed Ali Rahmaninezhad, C. Schauer, Christopher M. Sales, A. Najafi, Aidan Cotton, Amir Sadighi, Y. Farnam","doi":"10.1051/matecconf/202337802001","DOIUrl":"https://doi.org/10.1051/matecconf/202337802001","url":null,"abstract":"The goal of this research is to develop innovative damage-responsive bacterial-based self-healing fibers (hereafter called BioFiber) that can be incorporated into concrete to enable two functionalities simultaneously: (1) crack bridging functionality to control crack growth and (2) crack healing functionality when a crack occurs. The BioFiber is comprised of a load-bearing core fiber, a sheath of bacteria-laden hydrogel, and an outer impermeable strain-responsive shell coating. An instant soaking manufacturing process was used with multiple reservoirs containing bacteria-laden, hydrophilic prepolymer and crosslinking reagents to develop BioFiber. Sodium-alginate was used as a prepolymer to produce calcium-alginate hydrogel via ionic crosslinking on the core fiber. The dormant bacteria (spore) of Lysinibacillus sphaericus was incorporated in hydrogel as a self-healing agent. Then, an impermeable polymeric coating was applied to the hydrogel-coated core fibers. The impermeable strain-responsive shell coating material was manufactured using the polymer blend of polystyrene and polylactic acid. The high swelling capacity of calcium-alginate provides the water required for the microbially induced calcium carbonate precipitation (MICP) chemical pathway, i.e., ureolysis in this study. The strain-responsive impermeable coating provides adequate flexibility during concrete casting to protect the spores and alginate before cracking and sufficient stress-strain behavior to grant damage-responsiveness upon crack occurrence to activate MICP. To evaluate the behavior of developed BioFiber, the swelling capacity of the hydrogel, the impermeability of shell coating, the spore casting survivability, and MICP activities were investigated.","PeriodicalId":18309,"journal":{"name":"MATEC Web of Conferences","volume":"104 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86920352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Simulation analysis of internal and external faults in transformer area 变压器区内外故障的仿真分析

MATEC Web of Conferences Pub Date : 2023-01-01 DOI: 10.1051/matecconf/202338201041

Peixian Bai, Yixuan Jia

引用次数: 0

Initial proposal of a smart cement-based material to enhance the service-life of reinforcement concrete structures 一种智能水泥基材料的初步建议，以提高钢筋混凝土结构的使用寿命

MATEC Web of Conferences Pub Date : 2023-01-01 DOI: 10.1051/matecconf/202337805003

Ana Martínez-Ibernón, P. Antonaci, G. Anglani

{"title":"Initial proposal of a smart cement-based material to enhance the service-life of reinforcement concrete structures","authors":"Ana Martínez-Ibernón, P. Antonaci, G. Anglani","doi":"10.1051/matecconf/202337805003","DOIUrl":"https://doi.org/10.1051/matecconf/202337805003","url":null,"abstract":"The sustainable development of societies can be pursued by simultaneously avoiding the depletion of materials and resources and reducing the greenhouse gases emissions, with related climatic change effects. In order to get this, the extension of structures service-life plays a significant role in saving natural resources, decreasing the overall anthropogenic carbon-footprint, and reducing building and demolition wastes. In order to achieve such prolongation of structures service-life, one of the most promising approaches is the development of Smart Structures. These are defined as structures that are able to self-sense some external stimuli such as stress or temperature variations, and internal conditions such as chloride penetration, concrete carbonatation, etc. Consequently, ongoing damage phenomena can be detected promptly, thus allowing to implement suitable countermeasures in the most efficient way. Smart Structures can also process the information and respond autonomously in real time by using smart materials technologies such as self-healing technology. In this study we propose a preliminary version of a smart material system with self-healing and sensing properties, to demonstrate its effectiveness at a proof of concept level. The effectiveness of an active, capsule-based self-healing system in blocking chloride penetration through the crack and the effectiveness of voltametric Ag sensors in detecting the presence of chlorides were investigated experimentally. High-performance cement mortar was chosen as the material to be studied, in order to ensure that optimal behaviour could be observed in non-cracked conditions.","PeriodicalId":18309,"journal":{"name":"MATEC Web of Conferences","volume":"38 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90110221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of microstructure heterogeneity shapes on constitutive behaviour of encapsulated self-healing cementitious materials 微结构非均质形态对包封自愈胶凝材料本构行为的影响

MATEC Web of Conferences Pub Date : 2023-01-01 DOI: 10.1051/matecconf/202337809004

S. Sayadi, E. Ricketts, E. Schlangen, P. Cleall, I. Mihai, A. Jefferson

{"title":"Effect of microstructure heterogeneity shapes on constitutive behaviour of encapsulated self-healing cementitious materials","authors":"S. Sayadi, E. Ricketts, E. Schlangen, P. Cleall, I. Mihai, A. Jefferson","doi":"10.1051/matecconf/202337809004","DOIUrl":"https://doi.org/10.1051/matecconf/202337809004","url":null,"abstract":"Self-healing cementitious materials with microcapsules are complex multiscale and multiphase materials. The random microstructure of these materials governs their mechanical and transport behaviour. The actual microstructure can be represented accurately with a discrete lattice model, but computational restrictions mean that the size of domain that can be considered with this approach is limited. By contrast, a smeared approach, based on a micromechanical formulation, provides an approximate representation of the material microstructure with low computational costs. The aim of this paper is to compare simulations of a microcapsule-based self-healing cementitious system with discrete-lattice and smeared-micromechanical models, and to assess the relative strengths and weaknesses of these models for simulating distributed fracture and healing in this type of self-healing material. A novel random field generation technique is used to represent the microstructure of a cementitious mortar specimen. The meshes and elements are created by the triangulation method and used to determine the input required for the lattice model. The paper also describes the enhancement of the TUDelft lattice model to include self-healing behaviour. The extended micromechanical model considers both microcracking and healing. The findings from the study provide insight into the relative merits of these two modelling approaches.","PeriodicalId":18309,"journal":{"name":"MATEC Web of Conferences","volume":"49 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90164108","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A coupled radial-torsional lumped parameter model of rubber bushing for multibody dynamic simulations 多体动力学仿真橡胶衬套径向-扭转耦合集总参数模型

MATEC Web of Conferences Pub Date : 2023-01-01 DOI: 10.1051/matecconf/202338201023

Chang Cao, Xingxing Feng, Min Liu

引用次数: 0