公开(公告)号：US4046584A

公开(公告)日：1977-09-06

申请号：US681504

申请日：1976-04-29

申请人： Raymond C. Snyder ,  Paul F. Snyder

发明人： Raymond C. Snyder ,  Paul F. Snyder

IPC分类号： C04B22/00 ,  C04B24/26 ,  C04B28/02 ,  C04B7/35

CPC分类号： C04B28/02 ,  C04B22/0093 ,  C04B24/2664 ,  C04B2111/00482

摘要： There is disclosed a liquid accelerating additive for wet concrete which has a long shelf stability and which is ideally suited for use in shotcreting applications. The accelerating additive is a composition of sodium and potassium aluminates having the proportions of from 15 to about 40 weight percent alumina, and from 10 to about 25 weight percent of each of sodium and potassium, expressed as the oxides. The balance of the additive is water.The invention also includes a method of shotcreting in which wet concrete is sprayed against the surface of a structure, typically the wall and/or ceiling of a subterranean tunnel or cavern while incorporating in the wet concrete mixture a sufficient quantity of the liquid accelerating additive to control the setting of the concrete coating. The liquid accelerating additive can be incorporated into the concrete mixture by blending it into the water ingredient of the concrete which is admixed with a premixed, dry, solid component that includes the cement and aggregate or, if desired, can be blended into the wet concrete as the concrete is sprayed onto the surface.