Patents Assigned to Martin Limestone, Inc.
  • Lightweight concrete masonry unit
    Patent number: 6311444
    Abstract: The lightweight concrete masonry unit of the present invention contains, before being mixed with water, about 11 to 11.5% by weight of cement, about 47 to 47.5% by weight of pumice lightweight aggregate, about 22.5 to 23% by weight of other aggregate, about 18 to 18.5% by weight of sand, liquid color pigment as required to provide a desired color, and liquid admixture(s) as required to meet water impermeation standards.
    Type: Grant
    Filed: December 17, 1999
    Date of Patent: November 6, 2001
    Assignee: Martin Limestone, Inc.
    Inventor: John F. Sipe