Publications / 2020 Proceedings of the 37th ISARC, Kitakyushu, Japan

Construction Method of Super Flat Concrete Slab using High Precision Height Measurement

Yutaro Fukase, Ryosuke Saito, Yoshiaki Takemoto and Yoshiki Muramatsu
Pages 639-645 (2020 Proceedings of the 37th ISARC, Kitakyushu, Japan, ISBN 978-952-94-3634-7, ISSN 2413-5844)

The new Hachinohe indoor skating rink required an extremely flat concrete slab. ±2mm precision concrete surface was expected across 6,350 m2 concrete slab. It is impossible to construct such a large super flat slab with a conventional construction method to maintain the height of the concrete surface at intervals of few meters using human hands and eyes. Therefore, we have developed a construction method using high precision height measurement which maintains the height of the concrete surface in the levelling and the finishing processes with high density and precision. In the levelling process, a 18m long truss screed was used. Such a long truss screed is easily deformed and the deformation of the truss screed during the process directly leads to the deterioration of surface accuracy. Therefore, we developed a mechanism to measure and correct the deformation of the truss screed with high accuracy. In the finishing process we precisely scanned the levelled concrete surface with a 3D laser scanner. An unevenness distribution map was calculated from the scanned point-cloud data and projected onto the concrete surface using a projector to remove the concrete on the convex part. Finally, all the finished concrete surface was measured with a 3D laser scanner and confirmed that it had extremely high flatness.

Keywords: Flatness of Concrete; 3D Laser Scanner; Projection Mapping; Truss Screed