Dual Confinement Of Circular Concrete Columns By Cfrp Sheets And Lateral Steel Reinforcement

2013 ◽  
Author(s):  
Klaus Holschemacher ◽  
Stefan Käseberg
Keyword(s):  
Concrete Columns ◽  
Steel Reinforcement ◽  
Cfrp Sheets

scholarly journals Predicting the behavior of reinforced concrete columns confined by fiber reinforced polymers using data mining techniques

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Sahar Y. Ghanem ◽  
Heba Elgazzar
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Compressive Stress ◽  
Compressive Strain ◽  
Concrete Columns ◽  
Steel Reinforcement ◽  
Fiber Reinforced Polymers ◽  
Stress And Strain ◽  
Fiber Reinforced ◽  
The Impact

AbstractFiber Reinforced Polymer (FRP) usage to wrap reinforced concrete (RC) structures has become a popular technology. Most studies about RC columns wrapped with FRP in literature ignored the internal steel reinforcement. This paper aims to develop a model for the axial compressive strength and axial strain for FRP confined concrete columns with internal steel reinforcement. The impact of FRP, Transverse, and longitudinal reinforcement is studied. Two non-destructive analysis methods are explored: Artificial Neural Networks (ANNs) and Regression Analysis (RA). The database used in the analysis contains the experimental results of sixty-four concrete columns under the compressive concentric load available in the literature. The results show that both models can predict the column's compressive stress and strain reasonably with low error and high accuracy. FRP has the highest effect on the confined compressive stress and strain compared to other materials. While the longitudinal steel actively contributes to the compressive strength, and the transverse steel actively contributes to the compressive strain.

scholarly journals Influence of ties on the behavior of short reinforced concrete columns strengthened by external CFRP

2018 ◽  
Vol 162 ◽  
pp. 04005
Author(s):  
Kaiss Sarsam ◽  
Raid Khalel ◽  
Mohammed Hadi
Keyword(s):  
Carrying Capacity ◽  
Concrete Columns ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Load Carrying Capacity ◽  
Cfrp Sheets ◽  
Reinforced Polymer ◽  
Load Carrying ◽  
The Difference ◽  
Normal Strength

An experimental study was carried out to investigate the behavior of normal strength reinforce concret (RC) circular short column strengthned with “carbon fiber reinforced polymer (CFRP) sheets”. Three series comprising totally of (15) specimens loaded until failure under concentric compresion load. Strengthening was varied by changing the number of CFRP strips, spacing and wrapping methods. The findings of this research can be summarized as follows: for the columns without CFRP, the influence of the tie spacing was significant: compared with 130 mm tie spacing, dropping the spacing to 100 mm and 70 mm increased the load carrying capacity by 18% and 26%, respectively. The columns with less internal confinement (lesser amount of ties) were strengthened more significantly by the CFRP than the ones with greater amount of internal ties. As an example of the varying effectiveness of the fully wrapped CFRP, the column with ties at 130 mm was strengthened by 90% with the CFRP. In contrast, the ones with 70 mm spaced ties only increased in strength with CFRP by 66%. Compared with the control specimen (no CFRP), the same amount of CFRP when used as hoop strips led to more strengthening than using CFRP as a spiral strip- the former led to nearly 9% more strengthening than the latter in the case of 130 mm spaced internal steel ties. In the case of 100 mm internal steel ties, the difference (between the hoops & spiral CFRP strengthening) is close to 4%. In contrast, there is no difference between the two methods of strengthening in the heavily tied columns (70 mm tied spacing).

Stability analysis of CFRP-wrapped concrete columns strengthened with external longitudinal CFRP sheets

2008 ◽  
Vol 44 (3) ◽  
pp. 199-208 ◽  
Author(s):  
V. Tamuzs ◽  
V. Valdmanis ◽  
R. Tepfers ◽  
K. Gylltoft
Keyword(s):  
Stability Analysis ◽  
Concrete Columns ◽  
Cfrp Sheets

Behavior of CFRP Wrapped Concrete Columns with Partial Deteriorated Strength

2008 ◽  
Vol 47-50 ◽  
pp. 1282-1285 ◽  
Author(s):  
Hua Wei ◽  
Ji Sheng Li ◽  
Xia Guo
Keyword(s):  
Load Capacity ◽  
Concrete Columns ◽  
Frost Damage ◽  
Engineering Structures ◽  
Cfrp Sheets ◽  
Concrete Deterioration ◽  
Frp Composites ◽  
Reinforced Polymer ◽  
Partial Confinement ◽  
Transverse Strains

Fiber reinforced polymer (FRP) composites are becoming more frequently used in civil engineering structures because of their superiors advantages. While in practice, partial deterioration of concrete columns occurs occasionally, frost damage, aging or construction quality might lead to concrete deterioration. However, confined the whole columns including intact and deteriorated parts has been regarded as a waste. Few literatures have involved in partial confinement only to defect parts. The objective of this paper is to present an effective method to deal with the partial deteriorated strength columns, and to gain insight into the mechanical behavior of the defect part. Five groups of plain square columns are cast, different layers of CFRP sheets have been wrapped just on the deteriorated part to investigate the improvement with CFRP sheets and to verify the practicability of partial confinement. Columns are subjected to monotonic axial compression until failure occurs. Axial load, axial and transverse strains are measured to compare the different behaviors and to evaluate confinement level supplied by CFRP sheets. Experimental results show that partial confinement with CFRP can significantly enhance the strength and the ductility of the deteriorated strength part, then, the load capacity of the entire column can be improved subsequently.

BEHAVIOR OF CORRODED RC BEAMS WITHOUT STIRRUPS REPAIRED WITH CFRP SHEETS

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Abdullah Al-Saidy ◽  
Sherif El-Gamal ◽  
Khlaifa Al-Jabri ◽  
Bilal Waris
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structures ◽  
Strength Loss ◽  
Steel Reinforcement ◽  
Reinforced Concrete Beams ◽  
Experimental Program ◽  
Shear Reinforcement ◽  
Accelerated Corrosion ◽  
Cfrp Sheets ◽  
Externally Bonded

In reinforced concrete structures located in hot and humid areas, steel reinforcement is generally vulnerable to deterioration due to corrosion. Corrosion of reinforcement in many cases is considered the main cause of concrete structures deterioration, which in turn requires large budgets for repair and maintenance. This paper presents the experimental results of damaged/repaired reinforced concrete beams. The experimental program consisted of testing reinforced concrete rectangular beam specimen’s with/without shear reinforcement and exposed to accelerated corrosion of the longitudinal steel reinforcement on the tension side. Bonding external U-shaped CFRP sheets to restore the strength loss due to corrosion repaired corroded beams without shear reinforcement. The test results showed that corroded beams without stirrups failed in a brittle manner with drop in maximum deflection at failure of approximately 60% compared to the uncorroded beam. Corroded beams with stirrups lost some strength, but failed in ductile manner. Using externally bonded U-shaped CFRP sheets restored the ductility of corroded beams without stirrups and prevented bond failure at the steel concrete interface due to the absence of internal stirrups.

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