scholarly journals The Influence of Disorder in Multifilament Yarns on the Bond Performance in Textile Reinforced Concrete

10.14311/654 ◽  
2004 ◽  
Vol 44 (5-6) ◽  
Author(s):  
M. Konrad ◽  
R. Chudoba
Keyword(s):  
Reinforced Concrete ◽  
Failure Process ◽  
Bond Quality ◽  
Textile Reinforced Concrete ◽  
Bond Performance ◽  
Bond Layer ◽  
The Matrix ◽  
Multifilament Yarns ◽  
Modeling Strategy ◽  
Relative Differences

In this paper we analyze the performance of a bond layer between the multi-filament yarn and the cementitious matrix. The performance of the bond layer is a central issue in the development of textile-reinforced concrete. The changes in the microstructure during the loading result in distinguished failure mechanisms on the micro, meso and macro scales. The paper provides a brief review of these effects and describes a modeling strategy capable of reflecting the failure process. Using the model of the bond layer we illuminate the correspondence between the disorder in the microstructure of the yarn and the bonding behavior at the meso- and macro level. Particular interest is paid to the influence of irregularities in the micro-structure (relative differences in filament lengths, varying bond quality, bond-free length) for different levels of local bond quality between the filament surface and the matrix. 

scholarly journals Flexural Strengthening of Concrete Slab-Type Elements with Textile Reinforced Concrete

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2246 ◽  
Author(s):  
Hyeong-Yeol Kim ◽  
Young-Jun You ◽  
Gum-Sung Ryu ◽  
Kyung-Taek Koh ◽  
Gi-Hong Ahn ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Tensile Test ◽  
Tensile Properties ◽  
Surface Coating ◽  
Strengthening Effect ◽  
Test Results ◽  
Short Fibers ◽  
Textile Reinforced Concrete ◽  
Flexural Strengthening ◽  
The Matrix

This paper deals with flexural strengthening of reinforced concrete (RC) slabs with a carbon textile reinforced concrete (TRC) system. The surface coating treatment was applied to a carbon grid-type textile to increase the bond strength. Short fibers were incorporated into the matrix to mitigate the formation of shrinkage-induced cracks. The tensile properties of the TRC system were evaluated by a direct tensile test with a dumbbell-type grip method. The tensile test results indicated that the effect of the surface coating treatment of the textile on the bonding behavior of the textile within the TRC system was significant. Furthermore, the incorporation of short fibers in the matrix was effective to mitigate shrinkage-induced crack formation and to improve the tensile properties of the TRC system. Six full-scale slab specimens were strengthened with the TRC system and, subsequently, failure tested. The ultimate load-carrying capacity of the strengthened slabs was compared with that of an unstrengthened slab as well as the theoretical solutions. The failure test results indicated that the stiffness and the ultimate flexural capacity of the strengthened slab were at least 112% and 165% greater, respectively, than that of the unstrengthened slab. The test results further indicated that the strengthening effect was not linearly proportional to the amount of textile reinforcement.

scholarly journals Overlapped joints in Textile Reinforced Concrete with UHPC matrix: An experimental investigation

2021 ◽  
Vol 54 (4) ◽  
Author(s):  
Edoardo Rossi ◽  
Norbert Randl ◽  
Peter Harsányi ◽  
Tamás Mészöly
Keyword(s):  
Reinforced Concrete ◽  
High Performance ◽  
High Performance Concrete ◽  
Image Correlation ◽  
Reinforced Concrete Structure ◽  
Textile Reinforced Concrete ◽  
Premature Failure ◽  
Beneficial Effects ◽  
Out Of Plane ◽  
The Matrix

AbstractWhen producing a Textile Reinforced Concrete structure or element, joining separate textile layers might be a necessity, driven for example by the limited dimensions of commercially available fabrics. A possible way of producing such joints is by overlapping different textile sheets. Overlapped joints, however, need to be cast with particular attention since they might represents weak elements of the structure, leading to premature failure. An experimental campaign was performed, aimed at identifying the effects of a symmetric vs non-symmetric arrangement of the textile fabrics within the overlapping length and tensile characteristics of the matrix on such type of joints. Fifteen specimens, produced using a fully epoxy impregnated carbon textile fabric and an Ultra High Performance Concrete (UHPC) matrix, were tested under tension in a uniaxial setup and measurements were performed using a Digital Image Correlation system. The in-plane and out-of-plane behaviour of each specimen was studied. The results highlight the importance of producing symmetric elements as well as the beneficial effects that the admixture of short dispersed steel fibres to the cementitious matrix provide to such kind of joints

scholarly journals Control of Cracking in Textile Reinforced Concrete with Unresin Carbon Fibers

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3209
Author(s):  
Rui Neves ◽  
Diogo Felicíssimo
Keyword(s):  
Reinforced Concrete ◽  
Construction Material ◽  
Maximum Load ◽  
Deformation Monitoring ◽  
Textile Reinforced Concrete ◽  
Direct Tension ◽  
Mechanical Reinforcement ◽  
Crack Control ◽  
Tension Tests ◽  
The Matrix

Textile reinforced concrete (TRC) is an emerging construction material with interesting potential concerning sustainability, providing corrosion-free and lightweight solutions. Ordinarily, fiber bundles, impregnated with resin, are used. In this research the performance of reinforcement with unresin fibers is investigated. Control of cracking is considered the key performance factor and is assessed through tensile testing. However, economic and environmental aspects are addressed as well. Then, four different mixes/matrices were considered, without the addition of special/expensive admixtures. TRC ties were subject to direct tension tests, with load and deformation monitoring to assess the influence of mechanical reinforcement ratio on the cracking, failure and toughness of these composites, as well as of the matrix properties on the maximum load. It was observed that at a macro-level TRC behaves like conventional reinforced concrete, concerning crack control. Based on the maximum loads attained at the different composites, it was found that this particular TRC is economically viable. It is suggested that matrix workability may influence the maximum load.

scholarly journals A Practical Finite Element Modeling Strategy to Capture Cracking and Crushing Behavior of Reinforced Concrete Structures

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 506 ◽  
Author(s):  
Alexandre Mathern ◽  
Jincheng Yang
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Constitutive Relations ◽  
Fe Analysis ◽  
Rc Beams ◽  
Cracking Behavior ◽  
Concrete Cracking ◽  
Rc Structures ◽  
Nonlinear Fe Analysis ◽  
Modeling Strategy

Nonlinear finite element (FE) analysis of reinforced concrete (RC) structures is characterized by numerous modeling options and input parameters. To accurately model the nonlinear RC behavior involving concrete cracking in tension and crushing in compression, practitioners make different choices regarding the critical modeling issues, e.g., defining the concrete constitutive relations, assigning the bond between the concrete and the steel reinforcement, and solving problems related to convergence difficulties and mesh sensitivities. Thus, it is imperative to review the common modeling choices critically and develop a robust modeling strategy with consistency, reliability, and comparability. This paper proposes a modeling strategy and practical recommendations for the nonlinear FE analysis of RC structures based on parametric studies of critical modeling choices. The proposed modeling strategy aims at providing reliable predictions of flexural responses of RC members with a focus on concrete cracking behavior and crushing failure, which serve as the foundation for more complex modeling cases, e.g., RC beams bonded with fiber reinforced polymer (FRP) laminates. Additionally, herein, the implementation procedure for the proposed modeling strategy is comprehensively described with a focus on the critical modeling issues for RC structures. The proposed strategy is demonstrated through FE analyses of RC beams tested in four-point bending—one RC beam as reference and one beam externally bonded with a carbon-FRP (CFRP) laminate in its soffit. The simulated results agree well with experimental measurements regarding load-deformation relationship, cracking, flexural failure due to concrete crushing, and CFRP debonding initiated by intermediate cracks. The modeling strategy and recommendations presented herein are applicable to the nonlinear FE analysis of RC structures in general.

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