Cement accelerating agent

• US 4,650,523 A
• Filed: 05/17/1985
• Issued: 03/17/1987
• Est. Priority Date: 06/08/1984
• Status: Expired due to Fees

• Current Assignee: Onoda Cement Co., Ltd.
• Original Assignee: Onoda Cement Co., Ltd.
• Inventors: Omori, Hiroshi, Kikuchi, Masatsune, Matsui, Satoru, Shimoda, Masao
• Primary Examiner(s): Dixon, Jr., William R.
• Assistant Examiner(s): GROUP, KARL E
• Application Number:
  US06/735,791
• Time in Patent Office: 669 Days
• Field of Search: 106/85, 106/89, 106/314, 106/315
• US Class Current: 106/819
• CPC Class Codes: C04B 22/00 Use of inorganic materials as active ingredients for mortars, concrete or artificial stone, e.g. accelerators , shrinkage compensating agents
• CPC Class Codes: C04B 22/062 of the alkali or alkaline-earth metals
• CPC Class Codes: C04B 22/10 containing carbon in the anion
• CPC Class Codes: C04B 22/14 containing sulfur in the anion, e.g. sulfides
• CPC Class Codes: C04B 28/02 containing hydraulic cements other than calcium sulfates

Abstract

Initial setting, initial adhesion and long-term stability of mortar and concrete can be improved by use of a cement accelerating agent comprising (1) calcined alunite, a carbonate and lime, (2) calcined alunite, a carbonate and an aluminate, or (3) calcined alunite, a carbonate, an aluminate and lime.

Claims

1. A cement accelerating agent comprising 50 to 84 weight % of calcined alunite, prepared by calcining alunite at a temperature between 350°

and 750°

C., 15 to 30 weight % of an alkali metal carbonate and 1 to 25 weight % of lime.

4. A cement accelerating agent according to claim 1 wherein the lime is quicklime or slaked lime.

2. A cement accelerating agent comprising 50 to 94 weight % of calcined alunite, prepared by calcining alunite at a temperature between 350°

and 750°

C., 5 to 30 weight % of an alkali metal carbonate and 1 to 30 weight % of an alkali metal aluminate.

3. A cement accelerating agent comprising 50 to 89.9 weight % of calcined alunite, prepared by calcining alunite at a temperature between 350°

and 750°

C., 5 to 30 weight % of an alkali metal carbonate, 5 to 30 weight % of an alkali metal aluminate and 0.1 to 25 weight % of lime.

5. A cement accelerating agent according to claim 3 wherein the lime is quicklime or slaked lime.