The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 24, 1998
Filed:
May. 17, 1996
Ara Avedis Jeknavorian, Chelmsford, MA (US);
Ahmad Arfaei, Chelmsford, MA (US);
Neal Steven Berke, N. Chelmsford, MA (US);
David Charles Darwin, Columbia, MD (US);
Ellis Martin Gartner, Silver Spring, MD (US);
Leslie Ann Jardine, Ipswich, MA (US);
James Franklin Lambert, Chestnut Hill, MA (US);
Lawrence Reeder Roberts, Action, MA (US);
W. R. Grace & Co.-Conn., New York, NY (US);
Abstract
A high early strength admixture for precast hydraulic cement comprises a calcium salt and a copolymer having a carbon-containing backbone to which are attached cement-anchoring members, such as carboxyl groups, and to which are also attached oxyalkylene pendant groups by linkages selected from the group consisting of amide and imide members. The copolymers used are preferably formed by reacting an acrylic polymer with ammonia or an alkoxylated amine. The calcium salt, preferably calcium nitrite, and the copolymer can be added simultaneously as one admixture, or separately. The invention relates also to methods for enhancing high early strength in concrete, cement, masonry, and mortar mixtures generally, and to precast concrete particarly, and also pertains to such hydraulic mixtures containing the calcium salt and copolymer.