Fatigue Performance of Corroded RC Beams Strengthened with CFRP Sheets

2011 ◽  
Vol 243-249 ◽  
pp. 5589-5594
Author(s):  
Li Song ◽  
Zhi Wu Yu
Keyword(s):  
Fatigue Behavior ◽  
Effective Cross Section ◽  
Fatigue Performance ◽  
Fiber Reinforced Polymer ◽  
Rc Beams ◽  
Cfrp Sheets ◽  
Reinforced Polymer ◽  
Cross Section Area ◽  
Section Area ◽  
Steel Bars

The paper presents the results of an experimental study on fatigue performance of corroded reinforced concrete (RC) beams repaired with carbon fiber reinforced polymer (CFRP) sheets. Five beams were constructed. One specimen was strengthened and not corroded; another four specimens were corroded and was strengthened with CFRP sheets. Five specimens were tested in fatigue. The results showed that steel bars corrosion reduced the fatigue life significantly while the CFRP strengthening enhanced the fatigue performance significantly. The effects of reinforcement corrosion on fatigue behavior of the strengthening beam can be attributed to a combination of four factors, including deteriorated bond behavior between reinforcement bras and surrounding concrete, loss of effective cross-section area of reinforcement, the stress concentration on steel bars, and degradation of mechanical properties of steel bars.

Impact of efficiency and practicality of CFRP anchor installation techniques on the performance of RC beams strengthened with CFRP sheets

2019 ◽  
Vol 46 (9) ◽  
pp. 796-809 ◽  
Author(s):  
Mohammed A. Zaki ◽  
Hayder A. Rasheed
Keyword(s):  
Reinforced Concrete ◽  
Real World ◽  
Fiber Reinforced Polymer ◽  
Rc Beams ◽  
Application Time ◽  
Flexural Capacity ◽  
Cfrp Sheets ◽  
Reinforced Polymer ◽  
Real World Applications ◽  
And Performance

Utilizing fiber reinforced polymer (FRP) anchors can enhance the strength and delay the debonding of flexural FRP in strengthened reinforced concrete (RC) beams. In this study, two different techniques are used for applying carbon FRP (CFRP) spike anchors to improve the performance of RC beams strengthened with CFRP sheets. These two techniques are compared with respect to the ease of application, time spent, size of installation team, and performance. The first technique involved applying the CFRP anchors to begin with, then installing CFRP sheets by separating the fibers at the location of anchors. The second technique applied the CFRP sheets first to the beam soffit right after drilling the holes. This was followed by inserting CFRP anchors through the sheets into the prepared holes. The conclusion indicates that the second technique is easier, faster, and more practical in real-world applications. In addition, the use of distributed CFRP anchors increased the flexural capacity of the strengthened beams.

Flexural experimental study on reinforced concrete beams strengthened with carbon fiber-reinforced polymer laminates using anchorage systems

2019 ◽  
Vol 9 (8) ◽  
pp. 923-930
Author(s):  
Ning Zhuang ◽  
Junzhou Chen ◽  
Miao Zheng ◽  
Da Chen
Keyword(s):  
Carbon Fiber ◽  
Fiber Reinforced Polymer ◽  
Bending Test ◽  
Carbon Fiber Reinforced Polymer ◽  
Rc Beams ◽  
Fiber Reinforced ◽  
Flexural Capacity ◽  
Cfrp Sheets ◽  
Reinforced Polymer ◽  
Carbon Fiber Reinforced

Flexural capacity of RC beams gets significant improvement with externally bonded Carbon Fiber-reinforced Polymer (CFRP) sheet. The anchorage system is a valid means to restrain or delay debonding failure caused by stress concentration at the ends of CFRP sheets. In this paper, four RC beams, measuring 150 × 200 × 1900 mm, were examined under four-point bending test. One beam was applied for contrast. And other three were CFRP strengthened with no anchorage, CF anchors (carbon fiber anchors) and U-wraps (U-shaped CFRP wraps). The primary purpose of the experiment was to validate the effectiveness of CF anchors and U-wraps in improving the flexure character of beams strengthened with CFRP sheets. The experimental results revealed that the strengthened beams using anchorage systems performed remarkably in beam ductility, flexural capacity, load-deflection response and failure mode compared with the contrast beam. The anchorage systems were more effective and necessary to enhance the flexural behavior of beams as using CFRP laminates for flexural strengthening.

scholarly journals SHEAR CAPACITY PREDICTION FOR STIRRUP-CORRODED RC BEAMS STRENGTHENED WITH FRP

2019 ◽  
Vol 11 (1) ◽  
pp. 32-39 ◽  
Author(s):  
Ahmed K. El-Sayed
Keyword(s):  
Shear Capacity ◽  
Fiber Reinforced Polymer ◽  
Rc Beams ◽  
Accelerated Corrosion ◽  
Rc Structures ◽  
Cfrp Sheets ◽  
Four Point Bending ◽  
Reinforced Polymer ◽  
Shear Reinforcements ◽  
Corrosion Of Steel

Corrosion of steel reinforcement represents one of the main causes of deterioration and degradation of reinforced concrete (RC) structures. Shear reinforcements (stirrups) as an outer reinforcement in RC beams are more susceptible to corrosion problems and damage. This paper describes an analytical procedure for predicting the shear capacity of stirrup-corroded RC beams strengthened in shear using FRP laminates. The procedure shows how to incorporate the effects of the damages due to corrosion of stirrups into the design equations. An experimental investigation has been conducted to provide experimental data on the shear capacity of RC beams with corrosion-damaged stirrups strengthened using carbon fiber reinforced polymer (CFRP) sheets. The experimental study comprised three beams of 200 mm wide, 350 mm deep, and 2800 mm long. The steel stirrups in the beams were corroded using an accelerated corrosion technique. After CFRP strengthening, the beams were tested in four-point bending under a simply supported span of 2400 mm. The shear capacity of the strengthened beams was predicted using the proposed procedure and compared with the experimental ones. Good correlations were found between the predicted and experimental shear strength of the beams.

Thermal Fatigue Performance of Steel Fiber Reinforced Polymer High Strength Concrete

2012 ◽  
Vol 174-177 ◽  
pp. 1060-1066
Author(s):  
Hai Yang Wang ◽  
Pei Yan Huang ◽  
Xiao Hong Zheng ◽  
Xin Yan Guo
Keyword(s):  
Thermal Fatigue ◽  
High Strength Concrete ◽  
Steel Fiber ◽  
Fatigue Behavior ◽  
High Strength ◽  
Fatigue Performance ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Strength Concrete ◽  
Reinforced Polymer

To discover the fatigue behavior and durability of the new type fiber concrete named “steel fiber reinforced polymer high strength concrete (SFPHC)”, considering climatic conditions in Guangdong Province, using research method of theoretical analysis combined with experimental study, thermal fatigue behavior of SFPHC used in bridge superstructure in three different temperatures (20°C，50°C，80°C) is discussed and compared with concrete C60 which has similar static mechanical properties at room temperature. The results show that the thermal fatigue performance of SFPHC can be described effectively with the proposed computing formula, and the fatigue performance has been greatly enhanced compared with the C60 concrete.

Strain-Based Fatigue Analysis of RC Beams Strengthened with FRP Laminates

2012 ◽  
Vol 166-169 ◽  
pp. 1740-1745
Author(s):  
Li Hua Huang ◽  
Yu Jing Li ◽  
Tian Qing Li ◽  
Qing Xiang Wang
Keyword(s):  
Fatigue Behavior ◽  
Fatigue Analysis ◽  
Fiber Reinforced Polymer ◽  
Rc Beams ◽  
Behavior Prediction ◽  
Reinforced Polymer ◽  
Concentration Factors ◽  
Stress Ratios ◽  
Stress Concentration Factors ◽  
Neuber's Rule

The method of strain-based fatigue analysis is applied on the study of fatigue behavior of reinforced concrete (RC) beams strengthened with fiber reinforced polymer (FRP) laminates in this paper. Based on the investigation of fatigue performance of RC beams strengthened with FRP laminates presented in the published literatures, the values of stress concentration factors and the coefficients in Neuber’s rule are suggested. The exponent of fatigue strength in Manson-Coffin formula is discussed so as to having a general stain-life curve which is suitable for the fatigue behavior prediction of RC beam strengthened with FRP laminates. The S-N curves of different stress ratios can be developed and the fatigue lives of the strengthened beams are pointed out.

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