Experiment study on RC box beam strengthened with mounted prestressed CFRP sheets

2019 ◽  
Author(s):  
Tengfei Liang ◽  
Ying Lei
Keyword(s):  
Experiment Study ◽  
Cfrp Sheets ◽  
Box Beam ◽  
Prestressed Cfrp Sheets

Research on Interfacial Bond Behavior of Prestressed CFRP Sheets Strengthened SRC Beams under Symmetry Concentrated Loads

2011 ◽  
Vol 94-96 ◽  
pp. 1012-1017
Author(s):  
Na Ha ◽  
Shen Yuan Fu ◽  
Lian Guang Wang
Keyword(s):  
Interfacial Shear ◽  
Initial Strain ◽  
Concentrated Loads ◽  
Interfacial Bond ◽  
Steel Reinforced Concrete ◽  
Cfrp Sheets ◽  
Calculation Results ◽  
Minimum Potential ◽  
Effective Transfer ◽  
Prestressed Cfrp Sheets

The main form of interfacial bond stress between prestressed CFRP sheets and the beams of steel reinforced concrete(SRC) are interfacial shear and peel-off stress. The effective transfer of adhesive stress is the fundamental to ensure the structure bearing capacity improved after strengthened. According to the principle of minimum potential energy and combining with the mechanical behavior of prestressed CFRP sheets and the beams of SRC, the calculated formulas of interfacial shear and peel-off stress are deduced under symmetry concentrated loads. The influences of initial strain and the layer of CFRP sheets are discussed. The calculation results show that the effective availability of CFRP sheets is increased with the initial strain increasing under the load. And the interfacial shear and peel-off stress of beam-end are increased simultaneously with the initial strain and the layers of CFRP sheets increasing, which lead to the ends of beams occurred peel-off failure easily.

Analysis on Deformation of Pre-Splitting Steel Reinforced Concrete Beams Strengthened by Prestressed CFRP

2011 ◽  
Vol 243-249 ◽  
pp. 929-933
Author(s):  
Na Ha ◽  
Lian Guang Wang ◽  
Shen Yuan Fu
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Concrete Beams ◽  
Bending Moment ◽  
Reinforced Concrete Beams ◽  
Steel Reinforced Concrete ◽  
Cfrp Sheets ◽  
Deformation Curves ◽  
Prestressed Cfrp Sheets ◽  
Theoretical Results

In order to improve the bearing capacity of SRC which is related with deformation and stiffiness, SRC beams should be strengthened by CFRP. Based on the experiment of six pre-splitting steel reinforced concrete beams strengthened with (Prestressed) CFRP sheets, the deformation of beams are discussed. Load-deformation curves are obtained by the experiment. Considering the influence of intial bending moment on SRC beams, the calculated deformation formulas of SRC beams strengthened by (Prestressed) CFRP are deduced. The results showed that the load-deformation curves of normal and strengthened beams respectively showed three and two linear characteristics. The theoretical results which calculated by the formulas of deformation are well agreement with the experimental results.

Flexural behaviour of concrete beams strengthened with prestressed carbon fibre reinforced polymer sheets subjected to sustained loading and low temperature

2004 ◽  
Vol 31 (2) ◽  
pp. 239-252 ◽  
Author(s):  
Raafat El-Hacha ◽  
Mark F Green ◽  
R Gordon Wight
Keyword(s):  
Low Temperature ◽  
Carbon Fibre ◽  
Flexural Behaviour ◽  
Prestress Losses ◽  
Cfrp Sheets ◽  
Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Prestressed Cfrp Sheets

This paper presents results of an experimental investigation that examined concrete beams post-tensioned with bonded carbon fibre reinforced polymer (CFRP) sheets and then exposed to either room (+22 °C) or low (-28 °C) temperatures. The primary objective of this investigation was to assess the flexural behaviour of the strengthened beams after sustained loadings at both room and low temperatures. The strengthened beams showed significant increases in flexural stiffness and ultimate capacity as compared with the control-unstrengthened beams. Failure of the strengthened beams was by tensile rupture of the prestressed CFRP sheets. Test results showed that the long-term and low temperature effects did not adversely affect the strength of the beams. Long-term loading and low temperature exposure caused prestress losses in the CFRP sheets. The load–deflection behaviour of the long-term beams was predicted accurately by an analytical model. These results suggest that bonded prestressed CFRP sheets could be used to increase the strength of damaged prestressed concrete girders under extreme environmental conditions.Key words: strengthening, anchorage, low temperature, long-term, prestress losses, sustained load, carbon fibre reinforced polymer sheet.

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