To realize a lightweight molded body, which is excellent in impact resistance and has favorable nailing properties, by a method wherein the specified amount of lightweight inorganic foams, which have a specified average particle diameter and the reduction of volume of a specified value, and the specified amount of polypropylene fibers prepared by collecting a plurality of monofilaments having a specified average fiber length are added to a cement.
A mixture mainly consisting of a cement, a siliceous material, lightweight inorganic foams and reinforcing fibers is extrusion-molded. In this case, about 20-40 wt.% in solid content of the lightweight inorganic foam, the average particle diameter of which is 50 μm or less and the reduction of volume of which is 10% or less under the static water pressure of 5 MPa is added. Next, as the reinforcing fiber, a polypropylene fiber or the like is used. The fibers are prepared by collecting a plurality of monofilaments having the average fiber length of 3-18 mm. The loadings of these fibers to the mixture is 0.5-3 wt.%. Thus, a molded body, which is light in weight, has a favorable impact resistance and the nailing to which is easy and cracks in which due to nailing can be prevented from developing, is obtained.
NAKATANI MORIHITO
YAMAGUCHI ATSUSHI
