2020 Volume 76 Issue 1 Pages 99-111
It is considered that lifting and spalling concrete of arch crown is important for the maintenance of mountain tunnels, and it is assumed that these deformations are caused by repeated expansion and shrinkage around the cracks due to changes in the environment inside the tunnel. In addition, it is considered that the surface layer quality of the lining concrete of arch crown affects the long-term deterioration of the concrete surface. It is assumed that these surface deteriorations are affected by the quality of the construction method. In this study, it is focusing on the residual laitance at the overlapping part of arch crown. The overlapping part of arch crown was simulated, and the air permeability test, bending test, and restrained drying shrinkage test were performed. Furthermore, by comparing with the situation where the lining concrete was applied in the actual scale, the effects of residual laitance at the overlapping part of arch crown on cracks patterns and the surface quality were investigated.
