| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a cement-based treadboard for a staircase, which has a sufficient strength while achieving weight reduction. <P>SOLUTION: In the cement-based treadboard 1 for the staircase, a flat plate-like treadboard portion 2, and a plate-like riser portion 3, which rises, while abutting on the end surface 20 of the treadboard portion, from one side of the treadboard portion, are integrally extrusion-molded. The cement-based treadboard 1 is characterized as follows: two or more hollow portions 4 for weight reduction are provided in the treadboard portion 2 in the direction of extrusion; in a cross section perpendicular to the direction of extrusion, the tread-side wall-thickness x1 of the hollow portion A nearest to the riser portion of the hollow portions is thicker than the tread-side wall-thickness x2 of the hollow portion B nearest to the center of the treadboard portion. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
