scholarly journals Simulating FRP Debonding From Concrete Surface in FRP Strengthened RC Beams: A Case Study

2017 ◽  
Vol 24 (2) ◽  
pp. 452-466 ◽  
Author(s):  
Davood Mostofinejad ◽  
Sayed Jalil Hosseini
Keyword(s):  
1995 ◽  
Vol 6 (2) ◽  
pp. 9-20
Author(s):  
Hidenori Hamada ◽  
R.N. Swamy ◽  
Shin Tanikawa ◽  
Jaw-Chang Laiw

2012 ◽  
Vol 2012 ◽  
pp. 1-20 ◽  
Author(s):  
Sayed Mohamad Soleimani ◽  
Nemkumar Banthia

The effectiveness of externally bonded sprayed glass fiber reinforced polymer (Sprayed GFRP) in shear strengthening of RC beams under quasi-static loading is investigated. Different techniques were utilized to enhance the bond between concrete and Sprayed GFRP, involving the use of through bolts and nuts paired with concrete surface preparation through sandblasting and through the use of a pneumatic chisel prior to Sprayed GFRP application. It was found that roughening the concrete surface using a pneumatic chisel and using through bolts and nuts were the most effective techniques. Also, Sprayed GFRP applied on 3 sides (U-shaped) was found to be more effective than 2-sided Sprayed GFRP in shear strengthening. Sprayed GFRP increased the shear load-carrying capacity and energy absorption capacities of RC beams. It was found that the load-carrying capacity of strengthened RC beams was related to an effective strain of applied Sprayed GFRP. This strain was related to Sprayed GFRP configuration and the technique used to enhance the concrete-FRP bond. Finally, an equation was proposed to calculate the contribution of Sprayed GFRP in the shear strength of an RC beam.


2014 ◽  
Vol 13 (3) ◽  
pp. 071-078
Author(s):  
Szymon Chołostiakow ◽  
Renata Kotynia

The paper presents test results of an experimental program of four full-scale RC beams, strengthened in flexure with T-section carbon fiber reinforced polymer (CFRP) profiles and two reference beams subjected to a six point bending. The novel shape of CFRP profile combines both the near surface mounted (NSM) and externally bonded (EB) strengthening systems. The application of the CFRP profiles consisted of gluing both the web and the flange of the profile to the concrete surface. RC beams made of the same concrete class were differed by the internal steel reinforcement ratio and in a number of applied profiles. Efficiency of this new strengthening product was determined by comparison of the strengthened and non-strengthened RC beams. An increase of the CFRP-concrete bond area and high stiffness of the T-section profiles significantly improved the strengthening ratio (up to 130% of the reference beam) and reduced the maximum mid-span deflection (ranged of 70-80%) of the non–strengthened beams. The CFRP strain utilisation equal to 67% of the tensile strain corresponded to the maximum CFRP strains equal to 0,73%. The promising test results exhibit this system as a very attractive proposal of new strengthening technique used for field applications of the  existing structures.


2020 ◽  
Vol 1 (01) ◽  
pp. 23-39
Author(s):  
ALI SHUBBAR ◽  
Zainab Al-khafaji ◽  
Mohammed Nasr ◽  
Mayadah Falah

The concrete structures deterioration in the last few decades required effective methods for evaluating and maintaining the structure condition. Currently, assessing the performance and safety of reinforced concrete (RC) structures relies on routine-based visual inspection (VI). However, there are another non-destructive test (NDT) technique that can provide a more accurate assessment of the structures. Thus, in this study, a footbridge located in Liverpool, UK is chosen as a case study and has NDT techniques used for assessment. The main objective of this research is to determine the condition of structural bridge components and investigate its level of defect and deterioration using non-destructive tests. The methodologies involved are visual inspection, and NDT techniques include the rebound hammer, cover meter, Moisture Content & Depth of Carbonation Testing, Chloride Testing and Half Cell Test. The framework, when implemented with the best selection of NDT techniques, helps in determining the level of defect and deterioration of the structural bridge components and next recommendation regarding the condition of the bridge. The involved bridge structural components include column, deck, wall and staircase. Findings from the visual inspection show that there were many defects and deteriorations found at the structural bridge components, which includes crack, spalling, and delamination and rusting. Further, NDT techniques that were carried out at the selected bridge structural part shows that some of the components exhibited a moderate risk of corrosion and acceptable concrete surface quality. In general, further maintenance is needed specifically to some critical structural components of the bridge.


Author(s):  
Syahrur Romadhona ◽  
Fredy Kurniawan ◽  
Julistyana Tistogondo

The project acceleration by the Crash Program is one of the ways that is often used to make time and cost efficiency on an ongoing project. Acceleration of project completion time will affect the efficiency of equipment and labor productivity. In the case study of the Surabaya Outer East Ring Road Project Construction Segment 1, a project that has the potential to be accelerated is discussed in order to obtain efficiency values in terms of time and cost, Project acceleration by means of the Crash Program using the Precedence Diagram Method (PDM) method to determine the value of efficiency. This project uses resources, in this research the software used is Microsoft Project 2016. The research method used is to design network planning, find the critical path for each job, determine the work that has the potential to be accelerated, calculate the crash cost in additional working hours. and work shifts, calculating direct costs and indirect costs for each activity that changes due to changes in the duration of implementation, calculating the cost slope. Application of the Crash Program in the work of Asphalt Concrete Surface Layers (AC) thick 5 cm in the project will have an impact on increasing the time efficiency previously planned from 180 working days to 175 working days and efficiency with the difference in project costs of Rp. 18.313.935,8 with a ratio of 0,997 between the PDM method compared to the cost of the contract value calculated using the crashing project method.


2003 ◽  
Vol 52 (12) ◽  
pp. 1458-1463 ◽  
Author(s):  
Hidenori MORIKAWA ◽  
Takahiro YOSHIDA ◽  
Tomoshige KAMOTANI

2018 ◽  
Vol 163 ◽  
pp. 05003 ◽  
Author(s):  
Przemysław Czapik ◽  
Zdzisława Owsiak

On the basis of examinations of the efflorescences formed on the concrete surface, an attempt was made to analyze the sources of concrete corrosion without entering inside the construction. The concrete stairs revealed the symptoms of leaching, as a result of alkali-aggregate reactions developing beneath the surface. As a result of this corrosion process and the carbonation propagating from the concrete surface, the carbonate efflorescences were found. Their phase composition was determined by X-ray diffraction. In order to identify whether the efflorescences were the results of the alkali-silica reaction or alkalicarbonate reaction, the microstructure was investigated using the scanning electron microscope together with energy dispersive spectroscopy.


2016 ◽  
Vol 78 (5) ◽  
Author(s):  
Abdul Aziz Abdul Samad ◽  
Noorwirdawati Ali ◽  
Noridah Mohamad ◽  
Josef Hadipramana ◽  
Mohamad Zulkhairi Mohd Bosro

The purpose of this case study is to review the effect and contribution of CFRP laminates on shear strengthening and repair of reinforced concrete beams. To date, the method is yet to become a mainstream application due to number of economical and design related issues. The current experimental work consists of one control beam and four beams wrapped with CFRP laminates [5]. The CFRP configuration are either fully wrapped or U shaped with orientation at 0°/90° and 45°/135°. This case study then identifies several theoretical model developed by Triantafillou [6]; Triantafillou and Antonopolous [7]; Khalifa and Nanni [8][9]; Adhikary et al. [10]; Carolin and Täljsten [11], and Täljsten [12] along with three design codes i.e. ACI 440 [2], BCS [3] and fib [4] towards predicing the shear contribution of CFRP laminate. The results for both experimental and theoretical value were then compared in term of mean percentage difference to select the best theoretical shear prediction value. 


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