| 摘要 |
The present invention concerns an open spacer embedded in a slab which is capable of reducing concrete use. The spacer is hollow, whereof the cross section of the spacer is circular along the horizontal axis (X). The top and bottom of the open spacer are flat, wherein the horizontal (X) diameter (A) of the top is smaller than the horizontal (X) diameter (A) of the bottom and the vertical (Y) cross section is trapezoidal. The top and lateral surfaces of the open spacer are closed but the bottom surface is open. |
