Abstract: The present invention addresses the problem of increasing the bending strength of a board consisting of paper, the increased bending strength being obtained without largely increasing the thickness of the board. The present invention provides a board consisting of paper, the board comprising a board-shaped structure and a paperboard layer which is adhered to the board-shaped structure. The board-shaped structure includes a core, a first paper liner layer, and a second paper liner layer, the first and second paper liner layers being adhered to the core so that the core is sandwiched and held between the first and second paper liner layers. The paperboard layer is adhered to the first paper liner layer, the thickness of the board-shaped structure is in the range of approximately 15 mm to approximately 40 mm, the thickness of each of the first paper liner layer and the second paper liner layer is in the range of approximately 0.5 mm to approximately 1.

Abstract: To render a formwork (10), having a hollow (11b) defined therein and embedded in the elongated concrete member (40) during casting of a concrete material, to be lightweight, environmentally friendly and inexpensive and to have a sufficient strength, the formwork (10) includes a tubular member (11) formed by bending an oblong plate of corrugated cardboard (5) made of paper. The corrugated cardboard plate (5) includes a plurality of corrugated cardboards (3) laminated together and each formed by bonding liner sheets (2) to surfaces of a corrugated sheet (1). The corrugated cardboards (3) are laminated together with flutes of the corrugated cardboards (3) oriented in a direction (P) across a thickness of the corrugated cardboard plate (5), and a sheet (4) is bonded to front and rear major surfaces thereof.