Effective application of FRP to concrete structure is not possible until a fundamental understanding of the mechanics and failure mechanisms of the retrofit system is available. This paper is mainly focused on developing a methodology for predicting the debonding failure caused by intermediate flexural cracks in FRP-strengthened R/C beam. Firstly, based on the strain compatibility, an iterative...

Using a genetic algorithm owing to high nonlinearity of constraints, this paper first works on the optimal design of two-span continuous singly reinforced concrete beams. Given conditions are the span, dead and live loads, compressive strength of concrete and yield strength of steel; design variables are the width and effective depth of the continuous beam and steel ratios for positive and nega...

Most of the previous researches conducted on shear lag of box girders were only concerned about simple types of structures, such as simply supported and cantilever beams. The structural systems concerned in these previous researches were considered as determined and unchangeable. In this paper, a finite element method considering shear lag and creep of concrete was presented to analyze the effe...

Externally bonded carbon-epoxy fiber-reinforced polymers (CFRPs) have been widely used to restore or increase the capacities of reinforced concrete beams (Meier et al., 1992; Neale and Labossière, 1997; Varastehpour and Hamelin, 1997). A typical reinforced concrete bridge deck may experience up to 7x10 stress cycles during the course of a 120year life span (Barnes and Mays, 1999), while an over...

Laboratory fracture toughness tests of concrete using wedge-loaded round double beam specimens with a length to diameter ratio of 2:1 show two distinctly different specimen behaviors. Either the crack remains in the plane of the notch, and a valid test result can be obtained, or there is lateral cracking around mid-length which invalidates the results. Results of a controlled study show that th...

D analyses of structures responding elastically to ground motions recorded during severe earthquakes have shown that the theoretical response inertia loads are generally significantly greater than the static design lateral loads recommended by codes. Hence, structures designed for the lateral earthquake loads recommended by codes can only survive severe earthquakes if they have sufficient ducti...

In this study, tapered polymer fiber sensors (TPFSs) have been employed to detect the vibration of a reinforced concrete beam (RC beam). The sensing principle was based on transmission modes theory. The natural frequency of an RC beam was theoretically analyzed. Experiments were carried out with sensors mounted on the surface or embedded in the RC beam. Vibration detection results agreed well w...

–– This paper presents an Artificial Neural Networks (ANN) model for the cost optimization of simply supported beams designed according to the requirements of the ACI 318-08 code. The model formulation includes the cost of concrete, the cost of reinforcement and the cost of formwork. A simply supported beam was designed adopting variable cross sections, in order to demonstrate the model capabil...

At highly congested reinforcement regions, which is common at beam-column joint area, clear spacing between parallel bars becomes less than maximum normal aggregate size (20mm) which has not been addressed in any design code and specifications. Limited clear spacing between parallel bars (herein after thin cover) is one of the causes which affect anchorage performance. In this study, an experim...

A comprehensive computational model to simulate the nonlinear seismic response of composite frames with rectangular concrete-filled steel tube (RCFT) beam-columns and steel girders and braces is presented in this work. A three-dimensional fiber-based distributed plasticity mixed finite element formulation is introduced. The finite element formulation of RCFT beam-columns was derived with separa...