The background and current state of the art of ground penetrating radar testing of rebar in concrete is briefly reviewed. This encompasses developments of Polarization in rebar detection, diameter detection, corrosion detection,neural network and other automatic method in rebar detection.

Initiation of corrosion on reinforcing bars occurs when a critical chloride concentration is achieved. A universal value for the chloride concentration that causes depassivation has not been agreed upon for carbon steels due to a variety of experimental factors. The chloride threshold depends on the rebar material, rebar surface condition, testing environment, method of detection, definition of...

As a preliminary study for the erection of floating structures using high performance concrete, this paper examines the bond characteristics between concrete and the reinforcing bar. Since the floating structure is constructed in aquatic environment, corrosion of the reinforcing steel is likely to develop more prematurely than in onshore structure in case of concrete cracking. A solution to thi...

This study presents the modeling of pull-out behavior deformed bars embedded inside reinforced concrete element. The simulation uses an in-house finite element package called 3D-NLFEA. Sufficiently small solid elements that consider frictional resistance and mechanical interlocking between bar thread matrix were used in simulation. effect compressive strength, cover thickness, stirrup configura...

Automated rebar detection in images from groundpenetrating radar (GPR) is a challenging problem and difficult to perform in real-time as a result of relatively low contrast images and the size of the images. This paper presents a rebar localization algorithm, which can accurately locate the pixel locations of rebar within a GPR scan image. The proposed algorithm uses image classification and st...

The life of a concrete bridge exposed to deicing salt or seawater has often been limited by corrosion of the steel reinforcement. The service life of a concrete structure, degraded by corrosion, is considered to be the sum of the initiation and propagation periods. The initiation phase is the time required for sufficient accumulation of aggressive species at the rebar surface to initiate corros...

The synthesis of rebar graphene on Cu substrates is described using functionalized boron nitride nanotubes (BNNTs) that were annealed or subjected to chemical vapor deposition (CVD) growth of graphene. Characterization shows that the BNNTs partially unzip and form a reinforcing bar (rebar) network within the graphene layer that enhances the mechanical strength through covalent bonds. The rebar ...

Micro cracks occurring in concrete around tensile rebar is well known latent damage phenomenon. These micro cracks develop, and can be detected after reaching the surface of the concrete. Detection of these cracks before they are fully formed is preferable, but observing the whole crack structure is difficult. Another problem is repairing micro cracks under the concrete surface. The autogenous ...