| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To prevent hair cracks in the mortar lining layer. <P>SOLUTION: A method of manufacturing a mortar lining pipe comprises supplying unhardened mortar m mixed with aggregates into a pipe body 1 and rotating the pipe body 1 by a rotating means A to consolidate the mortar m under the centrifugal force produced by the rotation, and the aggregates contain porous sand or hollow silica grains. The mortar m is consolidated, under the centrifugal force produced by the rotation of the pipe body 1, into separated layers: a cement paste layer 2a near to the axis of the pipe body 1 and a cement mortar layer 2b distant from the axis. Since the porous sand or hollow silica particles has a bulk density lower than those of other aggregates contained in the mortar m, there is dispersed more porous sand or hollow silica grains in the cement mortar layer 2b than in the cement paste layer 2a, leading to a function as a reinforcing material. Drying shrinkage of the mortar m is also controlled because water is retained in the void of the porous sand or hollow silica grains, preventing occurrence of hair cracks. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
