Abstract. Acoustic Emission (AE) is one of the tools that can be used to detect the crack and to classify the type of the crack of reinforced concrete (RC) structure. Dislocation or movement of the material inside the RC may release the transient elastic wave. In this situation, AE plays important role whereby it can be used to capture the transient elastic wave and convert it into AE parameters such as amplitude, count, rise time and duration. Certain parameter can be used directly to evaluate the crack behavior. But in certain cases, the AE parameter needs to add and calculate by using related formula in order to observe the behavior of the crack. Using analysis of average frequency and RA value, the crack can be classified into tensile or shear cracks. In this study, seven phases of increasing static load were used to observe the crack behavior. The beams were tested in two conditions. For the first condition, the beams were tested in original stated without strengthened with carbon fibre sheet (CFS) at the bottom of the beam or called as tension part of the beam. For the second condition, the beams were strengthened with CFS at the tension part of the beam. It was found that, beam wrapped with CFS enhanced the strength of the beams in term of maximum ultimate load. Based on the relationship between average frequency (AF) and RA value, the cracks of the beams can be classified.

Beam-column joint in reinforced concrete (RC) structure is a critical element that needs to be monitored continuously throughout its service life. The beam-column connection acts as the core component that receives moment transfer from adjacent elements. Consequently, the integrity of the RC beam-column joint reduces when subjected to load over time. This study investigates the damage of RC beam-column joint subjected to static load until failure using acoustic emission (AE) signal strength. The size of the RC joint sample was composed of 300mm x 200mm x 600mm, 200mm x 200mm x 1200mm and 1500mm x 500mm x 300mm for beam, column and foundation respectively. The vertical loading was applied to the beam at 530 mm distances from the column surface. Four sensors were used at specified positions at the beam and column surfaces. It was found that the increment of load intensity results in intensified acoustic emission signal strength.