This paper introduces a novel and simple model for estimation of the shear contribution of the fiber-reinforced polymer (FRP) strengthening system in the FRP-strengthened beams. The model utilizes the bonding-based approach, which considers the shear resisting mechanism of FRP-strengthened beam via the bond behavior between FRP strengthening system and concrete. Herein, the beams strengthened in shear with near-surface mounting (NSM) rods or laminates and embedded through-section (ETS) bars are examined. By utilizing only mechanical consideration, the shear resistances of the NSM-strengthening or ETS-strengthening laminates or bars in the beams are simply derived when several bond factors (i.e. maximum bond stress and slip at peak bond stress) are known without using any empirical coefficients. The reliability of the proposed model is first validated against the test results available in the open literature. The extensive investigation to complement the model validation is then carried out through comparison of the results produced by the experiments and the proposed approach as well as the existing methods. The analyses demonstrate that the bondingbased approach is greatly effective to predict the shear contribution of the FRP strengthening system in the beam. Two examples for calculation of the shear resisting forces of the ETS-FRP and NSM-FRP bars in the FRP-strengthened beams are provided to depict the use of the model.

Fiber reinforced cementitious mortar (FRCM) systems, innovative strengthening systems, for repairing and strengthening concrete and masonry structures are an alternative option to traditional techniques such as fiber reinforced polymers (FRPs), steel plated bonding, and section enlargement. In this paper, a FRCM strengthening system made of polypara phenylene benzobisoxazole (PBO) fiber mesh embedded in cementitious matrix and bonded to concrete is investigated. There are two main parts in this paper: (i) the effective bond length of PBO mesh in PBO-FRCM system and (ii) the bond stress-slip relationship between PBO mesh and concrete substrate. An experimental program of single pull-out shear tests for the PBO-FRCM system is designed and conducted to verify the above two purposes. The results of this study can be used to estimate the effective bond length of PBO mesh in PBO-FRCM systems and also investigate if the debonding phenomenon occurs in the cementitious matrix or at the fiber and matrix interface. The comparison between the PBO-FRCM system and the ordinary FRP system is also discussed.

The survival of a large number of buildings in southern Thailand with minor structural damage under 2–6 m inundation heights above the ground in the 2004 Indian Ocean tsunami tragedy suggests that it is necessary to calibrate the formulas stipulated by FEMA-55 [2000] for computing tsunami loadings. In this study, the weather monitoring building of the Meteorological station at Takua Pa, Phang Nga is used as the case study. The building suffered only minor structural damage to the columns and girders. However, most of the nonstructural members such as infill brick panels were damaged, except a few which contributed to significant reserve strength against the tsunami attack. The FEMA-55 loading is calibrated with the actual building performance from a field load test. The maximum velocity that occurred at the site in that event is assessed, and a velocity suitable for computation of tsunami load for southern Thailand is recommended.

In this paper, the performances of reinforced concrete (RC) beams strengthened in shear with steel fiber-reinforced concrete (SFRC) panels are investigated through experiment, analytical computation, and numerical analysis. An experimental program of RC beams strengthened by using SFRC panels, which were attached to both sides of the beams, is carried out to investigate the effects of fiber volume fraction, connection type, and number and diameter of bolts on the structural responses of the retrofitted beams. The current shear resisting model is also employed to discuss the test data considering shear contribution of SFRC panels. The experimental results indicate that the shear effectiveness of the beams strengthened by using SFRC panels is significantly improved. A three-dimensional (3D) nonlinear finite element (FE) analysis adopting ABAQUS is also conducted to simulate the beams strengthened in shear with SFRC panels. The investigation reveals the good agreement between the experimental and analytical results in terms of the mechanical behaviors. To complement the analytical study, a parametric study is performed to further evaluate the influences of panel thickness, compressive strength of SFRC, and bolt pattern on the performances of the beams. Based on the numerical and experimental analysis, a shear resisting model incorporating the simple formulation of average tensile strength perpendicular to the diagonal crack of the strengthened SFRC panels is proposed with the acceptable accuracy for predicting the shear contribution of the SFRC system under various effects.

This paper presents an experimental and numerical investigation on concrete members strengthened by embedded through-section (ETS) steel and glass fiber-reinforced polymer (GFRP) bars attached preferably with mechanical anchorage at the tension ends. The pullout tests to analyze the bond performance between ETS bars and concrete under various influences such as anchorage presence, embedment length, ETS bar diameter, ETS-material types, and anchorage length are carried out. An analytical method for deriving the local bond stress-slip relationship of GFRP barsconcrete interfaces is developed. The overall responses of the pullout test specimens in terms of pullout force-slip curves, failure modes and strain profiles along the embedment length are discussed. Based on a careful interpretation, the analytical results demonstrated the effectiveness of the local bond stress-slip model developed in this study. Additionally, the finite element (FE) simulation of the beams intervened with ETS bars, which were tested in a previous study by the authors, incorporating with the proposed interfacial model is conducted. Comparison between the results achieved from the FE modelling and the experiment implies that the FE method was an accurately applicable tool to assess the behaviors of the beams strengthened in shear by ETS bars.