Improved numerical approach for evaluating the behavior of reinforced concrete members with flexural strengthening using strain hardening cementitious composite

Various factors, including increase in traffic volume and weight, structural aging, and environmental impact, cause damage in structural members. This raises the importance of the maintenance, rehabilitation, and strengthening of reinforced concrete members. External post-tensioning is one of the widely-used strengthening techniques in many countries due to its advantages over other strengthening methods. Although flexural strengthening of existing structural members is a well-established method, shear strengthening of structural members, especially with existing shear cracks, has attained very little attention from researchers. Similarly, external fiber-reinforced polymer (FRP) bonding for shear strengthening of structural members, especially with existing shear cracks, is a relatively new area of research. This paper presents the results of an experimental study on the shear strengthening of reinforced concrete (RC) beams with existing shear cracks by external post-tensioning and external FRP bonding. The test result showed that the combined strengthening technique of external post-tensioning and external FRP bonding can effectively increase the shear capacity of RC beams with existing shear cracks.

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Analytical and Experimental Study of Flexural Strengthening of RC Members using Mechanically Fastened FRP Strips

Advanced Composites Letters ◽

10.1177/096369351102000104 ◽

2011 ◽

Vol 20 (1) ◽

pp. 096369351102000

Author(s):

Angeliki Papalou ◽

Thanasis C. Triantafillou

Keyword(s):

Reinforced Concrete ◽

Reinforced Concrete Beams ◽

Fiber Reinforced Polymer ◽

Flexural Strengthening ◽

Concrete Members ◽

Four Point Bending ◽

Reinforced Polymer ◽

Mechanically Fastened ◽

Frp Strips ◽

Increasing Load

The main objective of this work is to investigate the behaviour of reinforced concrete members strengthened for flexure using mechanically fastened fiber reinforced polymer (FRP) strips. Experiments were conducted on strengthened reinforced concrete beams loaded to failure with an increasing load in four-point bending. An analytical-numerical model was developed predicting the behaviour of the strengthened concrete beam and reproducing its large ductility before failure.

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Flexural Strengthening with Externally Poured Ultra High Toughness Cementitious Composites

Materials Science Forum ◽

10.4028/www.scientific.net/msf.675-677.579 ◽

2011 ◽

Vol 675-677 ◽

pp. 579-582

Author(s):

Nan Wang ◽

Shi Lang Xu

Keyword(s):

Reinforced Concrete ◽

Flexural Behavior ◽

Structural Behavior ◽

Cementitious Composites ◽

Surface Cracks ◽

Flexural Strengthening ◽

Existing Structures ◽

High Toughness ◽

Concrete Members ◽

Flexural Bearing Capacity

The flexural behavior of reinforced concrete (RC) members strengthened with postpoured Ultra High Toughness Cementitious Composites (UHTCC) was investigated in this paper. The flexural behavior, failure mode and crack propagation during loading process of composite specimens were studied, and their structural behavior was also compared to that of original members. The experimental results showed that post-poured UHTCC materials enhanced flexural bearing capacity and toughness of existing concrete members. And introducing UHTCC material into strengthening enabled the composite specimens sustain the loading at a larger deflection without failure. It also revealed that post-poured UHTCC layer dispersed larger cracks in upper concrete into multiple tightly-spaced fine cracks, which prolonged the appearance of harm surface cracks and improved the durability of existing structures.

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