https://ira.lib.polyu.edu.hk/bitstream/10397/5409/1/01%20Analysis-oriented%20models.pdf

Analysis-oriented stress–strain models for FRP–confined concrete

Effect of corner radius on the performance of CFRP-confined square concrete columns: Test

Effect of cross-sectional aspect ratio on the strength of CFRP-confined rectangular concrete columns

Unified stress–strain model of concrete for FRP-confined columns

Most existing models for evaluating the strength of fiber-reinforced polymer (FRP)-confined concrete columns are based in an early work. In this paper, a new model based on the Hoek-Brown failure criterion is proposed. The existing strength models for FRP-confined circular and square concrete columns are reviewed, evaluated, and compared with the proposed model. An updated database that includes a large number of test data are then used to evaluate the models. Comparisons between the models and the test results demonstrate the accuracy of the proposed model. Apart from this improved accuracy, the proposed model also has a unified form for both circular and square columns, and can be used to predict the strength of columns that have existing damage or cracks. Test data for FRP-repaired concrete columns are collected from the literature and used to evaluate and demonstrate the performance of the proposed model in predicting the strength of FRP-confined deficient columns.

Unified Strength Model Based on Hoek-Brown Failure Criterion for Circular and Square Concrete Columns Confined by FRP

Extensive investigations on seismic retrofitting of reinforced concrete columns have been undertaken in recent years and many retrofitting methods have been developed and reported in the literature. However contradictory results and conclusions are not rare especially for jacketing of rectilinear columns, and there is not a clear picture on the current state-of-the-art in the literature. This work is based on the review and assessment of more than 120 papers, and collection and analysis of more than 700 column tests. In combination with the authors' original theoretical studies and experimental testing, this work identifies the key factors that affect the effectiveness and deficiencies of different retrofitting techniques and provides engineers with a clearer picture on the capabilities of different retrofitting techniques, in particular how to improve the effectiveness of a jacketing system. From the theoretical studies, this work also provides researchers with fundamental insight and principles that gov...

Fundamental Principles That Govern Retrofitting of Reinforced Concrete Columns by Steel and FRP Jacketing

Jacketing is less effective to large square/rectangular RC columns due to the inability of the rectangular-shaped jacket in restraining the dilation of concrete in the middle of a straight side. A new retrofit method is proposed in this work by fiber reinforcing the surface concrete in the middle of a straight side. Fiber reinforcing is achieved by inserting small fiber-reinforced polymer (FRP) bars into the concrete in the plastic hinge zone. The inserted FRP bars act as horizontal reinforcement to increase the ductility of the concrete in a similar way as that in normal fiber-reinforced concrete. When this fiber reinforcing technique is combined with the conventional jacketing, the concrete in all parts of a cross section may be effectively confined. In this work, experimental tests were undertaken to investigate the effectiveness of this new retrofit technique. Six half-scaled columns were tested and the test results demonstrated the effectiveness of the method.

Experimental investigation on seismic retrofitting of square RC columns by carbon FRP sheet confinement combined with transverse short glass FRP bars in bored holes

Tao Liu

Papers

Fundamental Principles That Govern Retrofitting of Reinforced Concrete Columns by Steel and FRP Jacketing

Experimental investigation on seismic retrofitting of square RC columns by carbon FRP sheet confinement combined with transverse short glass FRP bars in bored holes