Flexural strengthening of RC-structures by textile reinforced concrete in practical application

Author(s):  
S Weiland ◽  
E Lorenz ◽  
Ch Hankers ◽  
D Matzdorff
2019 ◽  
Vol 9 (7) ◽  
pp. 1322 ◽  
Author(s):  
Silke Scheerer ◽  
Robert Zobel ◽  
Egbert Müller ◽  
Tilo Senckpiel-Peters ◽  
Angela Schmidt ◽  
...  

Today, the need for structural strengthening is more important than ever. Flexural strengthening with textile reinforced concrete (TRC) is a recommendable addition to already proven methods. In order to use this strengthening method in construction practice, a design model is required. This article gives a brief overview of the basic behavior of reinforced concrete slabs strengthened with TRC in bending tests as already observed by various researchers. Based on this, a design model was developed, which is presented in the main part of the paper. In addition to the model, its assumptions and limits are discussed. The paper is supplemented by selected application examples to show the possibilities of the described strengthening method. Finally, the article will give an outlook on open questions and current research.


Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3856
Author(s):  
Young-Jun You ◽  
Hyeong-Yeol Kim ◽  
Gum-Sung Ryu ◽  
Kyung-Taek Koh ◽  
Gi-Hong Ahn ◽  
...  

Textile reinforced concrete (TRC) has widely been used for strengthening work for deteriorated reinforced concrete (RC) structures. The structural strengthening often requires accelerated construction with the aid of precast or prefabricated elements. This study presents an innovative method to strengthen an RC slab-type element in flexure using a precast panel made of carbon TRC. A total of five RC slabs were fabricated to examine the flexural strengthening effect. Two of them were strengthened with the precast panel and grouting material and another set of two slabs was additionally strengthened by tensile steel reinforcement. The full-scale slab specimens were tested by a three-point bending test and the test results were compared with the theoretical solutions. The results revealed that the ultimate load of the specimens strengthened with the TRC panel increased by at least 1.5 times compared to that of the unstrengthened specimen. The application of the precast TRC panel and grouting material for the strengthening of a prototype RC structure verified its outstanding constructability.


Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2246 ◽  
Author(s):  
Hyeong-Yeol Kim ◽  
Young-Jun You ◽  
Gum-Sung Ryu ◽  
Kyung-Taek Koh ◽  
Gi-Hong Ahn ◽  
...  

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.


2017 ◽  
Vol 36 (23) ◽  
pp. 1712-1726 ◽  
Author(s):  
Dejun Liu ◽  
Hongwei Huang ◽  
Jianping Zuo ◽  
Kang Duan ◽  
Yadong Xue ◽  
...  

For the eccentric compression structures which cannot be strengthened by wrap method, this paper presents an experimental and numerical study on flexural strengthening by applying textile reinforced concrete at the tensile face. Seven short columns were constructed and tested under eccentric load. One of the columns did not receive any strengthening and was used as the control column, whereas the rest six were externally upgraded by textile-reinforced concrete layers. The main parameters taken into account covered: (a) type of mortar, (b) preload level, and (c) number of textile-reinforced concrete layers. Besides the experimental program, a numerical investigation utilizing non-linear finite element analysis was carried out and a good agreement was obtained between the experimental and numerical results. Further, the numerical analysis was extended to additional cases to deepen the understanding of flexural-enhancing mechanism . It is concluded that textile-reinforced concrete substantially increases the flexural capacity of the eccentric compression columns; the more the textile layer, the greater the gain. However, the preload has an apparently adverse influence on the strengthening effectiveness, as it causes the strain loss of the textile; the bigger the preload level, the more the loss.


Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5046
Author(s):  
Hyeong-Yeol Kim ◽  
Young-Jun You ◽  
Gum-Sung Ryu

A textile reinforced concrete (TRC) system has been widely used for repair and strengthening of deteriorated reinforced concrete (RC) structures. This paper proposes an accelerated on-site installation method of a TRC system by grouting to strengthen deteriorated RC structures. Four RC slabs were strengthened with one ply of carbon textile grid and 20 mm-thick cementitious grout. The TRC strengthened slab specimens were tested under flexure and the test results were compared with those of an unstrengthened specimen and theoretical solutions. Furthermore, the TRC strengthened specimens experienced longer plastic deformation after steel yield than the unstrengthened specimen. The TRC strengthened specimens exhibited many fine cracks and finally failed by rupture of the textile. Therefore, TRC system with the proposed installation method can effectively be used for strengthening of deteriorated RC structural elements. The theoretically computed steel yield and ultimate loads overestimate the test data by 11% and 5%, respectively.


2021 ◽  
Author(s):  
Edoardo Rossi ◽  
Randl Norbert ◽  
Tamás Mészöly ◽  
Peter Harsányi

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1437
Author(s):  
Hyeong-Yeol Kim ◽  
Young-Jun You ◽  
Gum-Sung Ryu ◽  
Gi-Hong Ahn ◽  
Kyung-Taek Koh

Although carbon textile reinforcement widely used to replace the steel reinforcing bars but the bonding strength of carbon textile is generally much smaller than that of common steel bars. This study examines the strengthening effect of concrete slab-type elements strengthened in flexure by carbon textile reinforcement according to the surface coating of textile and the amount of reinforcement. The effect of the surface coating of textile on the bond strength was evaluated through a direct pullout test with four different sizes of coating material. The surface coated specimens developed bond strength approximately twice that of the uncoated specimen. The flexural strengthening effect with respect to the amount of reinforcement was investigated by a series of flexural failure tests on full-scale reinforced concrete (RC) slab specimens strengthened by textile reinforced concrete (TRC) system. The flexural failure test results revealed that the TRC system-strengthened specimens develop load-carrying capacity that is improved to at least 150% compared to the non-strengthened specimen. The strengthening performance was not significantly influenced by the textile coating and was not proportional to the amount of reinforcement when this amount was increased, owing to the change in the failure mode. The outstanding constructability afforded by TRC strengthening was verified through field applications executing TRC strengthening by shotcreting on a concrete box culvert.


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