| 摘要 |
A lightweight concrete float having a concrete shell surrounding either a hollow or buoyant foam core. The shell includes a deck surrounded by integrally formed, downwardly projecting side walls of sturdy but relatively heavy standard aggregate concrete and a bottom surrounded by integrally formed, upwardly projecting uniform or tapered side walls of lightweight but relatively weak foam aggregate concrete. Reinforcing rods are embedded along the edges of the deck, and a reinforcing mesh extends around the reinforcing rods and through the deck, side walls and bottom. The float may be formed by first pouring a layer of foam aggregate concrete into a form having a rectangular bottom surrounded by four sides. A block of buoyant foam is then placed on the bottom layer of concrete with the sides of the block spaced apart from the sides of the form. The space between the sides of the form and the sides of the block is partially filled with foam aggregate concrete. Standard aggregate concrete is then poured into the form in order to fill the remaining space between the sides of the form and the sides of the block and to cover the upper surface of the block. Vibration of the interface between the foam aggregate concrete and the standard aggregate concrete ensures firm bonding between the two concrete varieties. |
