| 摘要 |
<p>This invention relates to a method of making mortar or concrete pipes by centrifugal casting. The method is characterized by using mortar or concrete prepared from a cementiteous material incorporated with a salt of beta -naphthalenesulfonic acid-formaldehyde condensate, and curing the mortar or concrete pipes made by the above condition with high pressure steam in an autoclave.</p> |
