| 摘要 |
PROBLEM TO BE SOLVED: To provide an extruded cement board in which failures in manufacture such as pull cracks are eliminated, and fire-resistance performance and strength properties are improved.SOLUTION: An extruded cement board 10 is formed of multiple hollows 2 opened on both end surfaces in the longitudinal direction in a band plate-shaped board body 1, and has multiple longitudinal ribs 4 for connecting between both side walls 3 of the board body 1 in the lateral direction of the board body 1. Each longitudinal rib 4 is provided at a slant alternately to each other in the opposite direction, and is provided in conjunction with each other in the connection part with both side walls 3. Each cross section of the hollow 2 is defined in a triangle shape by each longitudinal rib 4. An overall thickness B of the board body 1 is 80 mm or more and 110 mm or less, and a thickness A of both side walls 3 is 20 mm or more and 25 mm or less. A thickness G of the longitudinal rib 4 is (A-5) mm or more and (A+5) mm or less. An apical angle &thetas; of the hollow 2 formed in the connection part of the longitudinal rib 4 is 45° or more and 120° or less. |
