scholarly journals Reinforced Concrete Slabs Strengthened with Carbon Textile Grid and Cementitious Grout

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5046
Author(s):  
Hyeong-Yeol Kim ◽  
Young-Jun You ◽  
Gum-Sung Ryu
Keyword(s):  
Plastic Deformation ◽  
Reinforced Concrete ◽  
Test Data ◽  
Concrete Slabs ◽  
Test Results ◽  
Structural Elements ◽  
Textile Reinforced Concrete ◽  
Rc Structures ◽  
Reinforced Concrete Slabs ◽  
Rc Slabs

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.

Behavior of Two-way RC Slabs Combination Strengthened with CFRP Strips and Steel Sheets

2014 ◽  
Vol 501-504 ◽  
pp. 1048-1052 ◽  
Author(s):  
Xiao Jin Li ◽  
Yi Yan Lu ◽  
Na Li
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Concrete Slabs ◽  
Test Results ◽  
Reinforced Concrete Slab ◽  
Steel Sheets ◽  
Reinforced Concrete Slabs ◽  
Rc Slab ◽  
Rc Slabs ◽  
Strengthening Technique

A total of four two-way reinforced concrete slabs strengthened with three methods were tested. The four test specimens were one unstrengthened reinforced concrete slab (control), one slab strengthened with CFRP strips, one slab strengthened with steel sheets, and one slab strengthened with an innovative method of applying CFRP strips and steel sheets combination bonding to the tension face of the slab. The test results show the CFRP-Steel combination strengthened technique is a rapid and effective strengthening technique for two-way RC slab. The increase in ultimate capacities of CFRP-Steel combination strengthened slab is 221.1% over the control slab, 84.4% over the CFRP-strengthened slab, and 45.2% over the steel-strengthened slab. In addition, the CFRP-Steel combination strengthened slab exhibited superior ductility than the CFRP-strengthened slab.

scholarly journals Reinforced Concrete Slabs Strengthened with Lap-Spliced Carbon TRC System

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3340
Author(s):  
Hyeong-Yeol Kim ◽  
Young-Jun You ◽  
Gum-Sung Ryu
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slabs ◽  
Textile Reinforced Concrete ◽  
Lap Splice ◽  
Flexural Failure ◽  
Reinforced Concrete Slabs ◽  
Tensile Performance ◽  
Matrix Properties ◽  
Rc Slab ◽  
Rc Slabs

Construction with precast or prefabricated elements requires the connecting of structural joints. This study presents an accelerated construction method to strengthen reinforced concrete (RC) slab-type elements in flexure using precast lap-spliced textile-reinforced concrete (TRC) panels. The objectives of this study are to identify the tensile behavior of a TRC system with lap-spliced textile, and to experimentally validate the performance of the proposed connecting method by flexural failure test for the concrete slabs strengthened by TRC panels with lap-spliced textile. Twenty-one coupon specimens were tested in tension with two different matrix systems and three different lap splice lengths. The influence of the lap splice length and matrix properties on the tensile performance of the TRC system was significant. Five full-scale RC slabs were strengthened by the precast TRC panels with and without the lap splice, and was tested in flexure. The results of the failure test for the strengthened specimens showed that the ultimate load of the strengthened specimen with the TRC panel increased by a maximum of 24%, compared to that of the unstrengthened specimen. Moreover, the failure-tested specimens were re-strengthened by a new TRC panel system and tested again in flexure. The objective of the re-strengthening of the damaged RC slabs by the TRC panel is to investigate whether the yielded steel reinforcement can be replaced by the TRC panel. The initial cracking load and the stiffness of the re-strengthened specimens were significantly increased by re-strengthening.

Critical shear crack theory-based punching shear model for FRP-reinforced concrete slabs

2020 ◽  
pp. 136943322097814
Author(s):  
Xing-lang Fan ◽  
Sheng-jie Gu ◽  
Xi Wu ◽  
Jia-fei Jiang
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Shear Crack ◽  
Concrete Strength ◽  
Weight Ratio ◽  
Punching Shear ◽  
Concrete Slabs ◽  
Crack Theory ◽  
Reinforced Concrete Slabs ◽  
Rc Slabs

Owing to their high strength-to-weight ratio, superior corrosion resistance, and convenience in manufacture, fiber-reinforced polymer (FRP) bars can be used as a good alternative to steel bars to solve the durability issue in reinforced concrete (RC) structures, especially for seawater sea-sand concrete. In this paper, a theoretical model for predicting the punching shear strength of FRP-RC slabs is developed. In this model, the punching shear strength is determined by the intersection of capacity and demanding curve of FRP-RC slabs. The capacity curve is employed based on critical shear crack theory, while the demand curve is derived with the help of a simplified tri-linear moment-curvature relationship. After the validity of the proposed model is verified with experimental data collected from the literature, the effects of concrete strength, loading area, FRP reinforcement ratio, and effective depth of concrete slabs are evaluated quantitatively.

scholarly journals Flexural Strengthening of RC Structures with TRC—Experimental Observations, Design Approach and Application

2019 ◽  
Vol 9 (7) ◽  
pp. 1322 ◽  
Author(s):  
Silke Scheerer ◽  
Robert Zobel ◽  
Egbert Müller ◽  
Tilo Senckpiel-Peters ◽  
Angela Schmidt ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Design Model ◽  
Textile Reinforced Concrete ◽  
Bending Tests ◽  
Rc Structures ◽  
Flexural Strengthening ◽  
Reinforced Concrete Slabs ◽  
Open Questions ◽  
Basic Behavior ◽  
Strengthening Method

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.

scholarly journals Strengthening of Concrete Element with Precast Textile Reinforced Concrete Panel and Grouting Material

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3856
Author(s):  
Young-Jun You ◽  
Hyeong-Yeol Kim ◽  
Gum-Sung Ryu ◽  
Kyung-Taek Koh ◽  
Gi-Hong Ahn ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Bending Test ◽  
Strengthening Effect ◽  
Textile Reinforced Concrete ◽  
Concrete Element ◽  
Rc Structures ◽  
Flexural Strengthening ◽  
Grouting Material ◽  
Rc Slab ◽  
Rc Slabs

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.

Calculation of Ultimate Loads of Two-Way Reinforced Concrete Slabs

2012 ◽  
Vol 256-259 ◽  
pp. 850-854
Author(s):  
Yong Wang ◽  
Yu Li Dong
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Load ◽  
Failure Criteria ◽  
Reinforcement Ratio ◽  
Concrete Slabs ◽  
Test Results ◽  
Simple Method ◽  
Simply Supported ◽  
Reinforced Concrete Slabs

This paper presents the latest developments of a simple method used to determine the ultimate load of two-way simply supported reinforced concrete slabs. Based on the reinforcement ratio, two failure criteria are proposed in the paper. The effectiveness of the developed model is validated through satisfactory comparison with from test results.

scholarly journals Punching shear behavior of thick reinforced concrete slabs according to Strut-and-Tie model

2014 ◽  
Vol 13 (3) ◽  
pp. 183-192
Author(s):  
Tadeusz Urban ◽  
Jakub Krakowski
Keyword(s):  
Reinforced Concrete ◽  
Experimental Test ◽  
Shear Behavior ◽  
Punching Shear ◽  
Concrete Slabs ◽  
Test Results ◽  
Strut And Tie ◽  
Reinforced Concrete Slabs ◽  
Symmetric Loading ◽  
Strut And Tie Model

The punching shear behavior of thick reinforced concrete slabs was analyzed in this paper by using strut-and-tie model (S-T). Calculating procedures were compared to our own experimental test results. The analyzed elements were subjected to symmetric loading and without shear reinforcement.

scholarly journals Experimental study of solid RC slabs strengthened on the upper surface

2018 ◽  
Vol 11 (2) ◽  
pp. 255-278
Author(s):  
C. O. CAMPOS ◽  
L. M. TRAUTWEIN ◽  
R. B. GOMES ◽  
G. MELO
Keyword(s):  
Experimental Study ◽  
Reinforced Concrete ◽  
Failure Load ◽  
Concrete Strength ◽  
Reinforcement Rate ◽  
Concrete Slabs ◽  
Minimum Reinforcement ◽  
Reinforced Concrete Slabs ◽  
Load Limit ◽  
Rc Slabs

Abstract The current study presents the results of tests conducted in 5 reinforced concrete slabs (415 cm x 415 cm x 7 cm) in order to experimentally check the possibility of reinforcing their upper surface, as well as to assess the adhesion between the old and the reinforcing concrete layers in the slab. The main variables were the concrete and reinforcement strength deficiencies. Reference slab “L1” was tested until reaching the failure load, whereas the others were tested until reaching certain load limit, reinforced and retested until reaching the failure load. All slabs failed under bending. The strengthening increased the failure load by 30% in slabs reinforced at minimum reinforcement rate when they were compared to similar non-reinforced slabs, regardless of the original concrete strength. None of the tests conducted in the reinforced slabs showed detachments or evidence of adhesion loss between the old and reinforcing concretes.

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