| 摘要 |
<p>PROBLEM TO BE SOLVED: To constitute a concrete footboard capable of enhancing flexural strength, capable of restraining a crack of concrete and having a footboard width of only about 1.8 to 3.0 m. SOLUTION: A riser projecting strip 22 is formed over the width directional total length on the upper surface of the inmost side 21a end part of a footboard main body 21, antislipping grooves 23, 23 are formed on the upper surface of this side 21b end part, and a draining groove 24 is formed on the under surface of this side 21b end part to constitute a footboard 20 having a width L. The other side of a nut member 13 exposed to the width L directional end surface of a footboard 20 is exposed, screw holes 25, 25 are formed, and a welding wire net is embedded along an outside surface shape of the footboard main body 21 and the riser projecting strip 22. A tension member 8 by introducing stress (about 10 to 30 kgf/cm<2> to a cross section of the footboard), is embedded over the whole width in the footboard 20.</p> |
