| 摘要 |
PURPOSE: To reduce the weight of stair treads so as to make it possible to use the stair treads whose shape is as required and the treads as a temporary staircase and enhance the manufacture and workability and hence cut down cost. CONSTITUTION: Stair treads 10 consist of a cross section-zigzag concrete layer 11 which buries reinforcements 20 inside and provides strings 12A and 12B. Treads 14 and risers 15 in conformity with a required number of steps are formed on the surface 13 of the concrete layer 11. A bottom tool frame 82 is provided with a bottom frame and a side frame. When a staircase is constructed, the bottom tool frame 82 is slanted at a specified angle between an upper story floor 80 and a lower story floor 81 and spanned and then reinforcements 83 are placed on the lower frame. Then, the stair treads 10 are laid out on the bottom tool frame 82 with a specified sap thus installed where concrete M3 is filled up from above between the stair treads 10 and the bottom tool frame 82. After the concrete is cured, the bottom tool frame 82 is removed and then the staircase is constructed. |
