| 摘要 |
<p>PURPOSE: To obtain a cover plate having required strength, weight and dimensional accuracy by fixing channels of a light metal to the rear side of a rectangular fiber reinforced concrete plate along the longitudinal direction thereof. CONSTITUTION: The cover plate 2 of an open duct is fixed with two channel bars of aluminum alloy to the rear side of a thin rectangular glass fiber reinforced concrete plate by means of a plurality of bolts and nuts. The glass fiber reinforced concrete plate is provided, on the opposite sides in the longitudinal direction thereof, with recesses 5 for inserting a hand to the rear side of the concrete plate 3 at the time of fixing the cover plate 2. The glass fiber reinforced concrete plate has dimensions of 200×500×22mm. The channel bar 4 is 1760mm long and has cross-sectional dimensions of 60×30×3mm. The cover plate 2 has a weight of 50kg or above and can not be handled easily by human power.</p> |
