Abstract

The authors present an analysis of the possibility to assess deformations and mode of failure of R-C beams using terrestrial laser scanning. As part of experiments carried out at the Regional Laboratory of Construction (at Gdansk University of Technology), reinforced concrete beams were subjected to destruction by bending and by shear. The process of press impact on the reinforced concrete beam was recorded using terrestrial laser scanner. Development of scanning effects was performed using Leica Cyclone software and MeshLab. In order to verify results, the independent recording of beam deflection with use of extensometer and the recording with non-meter synchronous digital cameras were carried out, photos from these cameras were subjected to photogrammetric processing. However, the principal subject of this paper is to show the usefulness of laser scanning for the analysis of reinforced concrete beams damages and authors of this paper focused on this subject. In the description of the experiment there are six stages of measurement mentioned for the reinforced concrete beam: from the zero condition (no force), through intermediate conditions up to the stage of destruction. Scanning was performed from one stable measurement station to avoid in processing the effect of correlation errors (matching and linking) of ScanWorld. Analysis of the materials from laser scanning allowed to assess the geometry of element subjected to destruction with an accuracy not worse than 1 mm. For this purpose, the method of spheres translation was developed and in its characteristic groups of points from scanning the spheres were described. Spheres centers grew to be geometrical element to be assessed on scans in subsequent measurement epochs. Additionally, through the use of automated analysis of intensity map of laser light reflection, it was indicated the possibility of rapid identification of the beam, in which there may occur microcracks and changes in the structure. The usefulness of the evaluation mechanism can be appreciated in the mass studies or inspective examinations of constructional components. As a result of the authors’ research and in the course of measurements analysis it was possible to establish the concise procedure to specify the mode of the reinforced concrete destruction and it was defined the minimum size of cracks that may be recorded in the cloud of points from laser scanning.

Citations

Authors (3)