| 摘要 |
PURPOSE:To provide the extrusion molding method of a explosive crack resist ant cement building material capable of imparting explosive crack resistance to this building material without impairing its product strength in the vacuum extrusion molding method which is liable to provided a dense structure. CONSTITUTION:An extrusion molding cement compd. prepd. by adding required amts. of an extrusion assistant and water to cement, siliceous raw material, aggregate and reinforcing fibers exclusive of asbestos includes 0.1 to 0.5wt.% synthetic fibers having a thermally shrinking property in the fibers to be added as the reinforcing fibers exclusive of the asbestos mentioned above. In addition, 0.05 to 1.0wt.% air entraining agent is added to 100 pts. compd. and the compd. is kneaded. This compd. is then shaped by extrusion molding under >=15kg/cm<2> extrusion molding pressure and the shape is aged and cured under a high-temp. condition. The structure to prevent the explosive crack by the microcells formed by the air entraining agent and the thermally shrinkable synthetic fibers communicating these cells with each other is obtd. by the stages described above. |
