Abdelhak Bousselham

Shear strengthening reinforced concrete beams with fiber-reinforced polymer: Assessment of influencing parameters and required research

This paper focuses on shear strengthening of reinforced concrete (RC) beams with externally bonded fiber-reinforced polymer (FRP) composites. Its aims are to synthesize findings of the research studies conducted to date, and to examine and analyze the parameters that have the greatest influence on the shear behavior of RC members strengthened with externally bonded FRP. Over 100 tests were considered in the synthesis. Several conclusions were drawn from this work and are discussed. It was found that the parameters related to the properties of the FRP and to those of the shear steel reinforcement are not the only ones having an influence on the shear behavior of RC members strengthened with externally bonded FRP. The shear span ratio a/d, longitudinal steel reinforcement ratio, and geometry of the member also have influence on the shear behavior of these members and deserve further investigation. An experimental parametric study with close variable control is recommended.

Behavior of reinforced concrete T-beams strengthened in shear with carbon fiber-reinforced polymer : An experimental study

The results of an extensive experimental investigation on reinforced concrete T-beams retrofitted in shear with externally bonded carbon fiber-reinforced polymer (CFRP) are presented. The authors researched the CFRP ratio, the internal shear steel reinforcement ratio and the shear length to the beams depth ratio. By studying the aforementioned parameters, the behavior of reinforced concrete T-beams strengthened in shear with externally applied CFRP was analyzed. It appears that the contribution of CFRP to shear resistance depends on if a strengthened beam is reinforced in shear with internal transverse steel reinforcement, and not on the CFRP stiffness provided. It seems that the American Concrete Institute and the Canadian Standards Association guidelines fail to incorporate the presence of the transverse resistance and overestimates the shear resistance for high fiber reinforced polymer thickness.

State of Research on Seismic Retrofit of RC Beam-Column Joints with Externally Bonded FRP

A considerable amount of research has been directed recently toward understanding and promoting the use of externally applied fiber-reinforced polymer (FRP) for the seismic retrofit of reinforced concrete (RC) structures. In this paper, a comprehensive review and synthesis of published experimental studies on the seismic rehabilitation of RC frame beam-column joints with FRP is presented, and the issues that need to be addressed for further research are discussed. In addition, the paper presents a simple design model for predicting the contribution of the FRP to the shear strength of retrofitted joints. The key element in the model is the derivation of an expression for the effective FRP strain, based on the calibration of test data reported in the literature. A total of 54 tests carried out worldwide were considered in the review, and a database of the published studies, encompassing all relevant design parameters, was assembled. The reported test results confirm the structural effectiveness of the FRP s...

Fatigue Performance of RC Beams Strengthened in Shear with CFRP Fabrics

In recent years, a tremendous effort has been directed toward understanding and promoting the use of externally bonded fiber-reinforced polymer (FRP) composites to strengthen concrete structures. Despite this research effort, studies on the behavior of beams strengthened with FRP under fatigue loading are relatively few, especially with regard to its shear-strengthening aspect. This study aims to examine the fatigue performance of RC beams strengthened in shear using carbon FRP (CFRP) sheets. It involves six laboratory tests performed on full-size T-beams, where the following parameters are investigated: (1) the FRP ratio and (2) the internal transverse-steel reinforcement ratio. The major finding of this study is that specimens strengthened with one layer of CFRP survived 5 million cycles, some of them with no apparent signs of damage, demonstrating thereby the effectiveness of FRP strengthening systems on extending the fatigue life of structures. Specimens strengthened with two layers of CFRP failed in ...