Patents by Inventor David A. Smetana

David A. Smetana has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Pumpable backfill grout
    Patent number: 5294255
    Abstract: A pumpable backfill grout which hardens into a controlled low strength material and an additive for making up such a backfill grout. The grout consists essentially of portland cement, a smooth surfaced vesicular expanded perlite, fly ash, fine aggregate, water, an air entraining agent, a quick dispersing thixiotropic suspending agent and a bentonite thickening agent.
    Type: Grant
    Filed: September 23, 1992
    Date of Patent: March 15, 1994
    Assignee: Specrete-IP Incorporated
    Inventors: David A. Smetana, Richard J. Lenczewski, Alfonzo L. Wilson
  • High strength structural perlite concrete
    Patent number: 5114617
    Abstract: A high strength concrete particularly useful for precast, prestressed products comprising by weight of the wet concrete mix, 8 to 60 percent cement, 0.5 to 20 percent smooth-surfaced, vesicular, expanded perlite, 5 to 30 percent water, 0 to 12 percent pozzolan, and fine aggregate and coarse aggregate as appropriate and available in the circumstances. The concrete provides superior bond to reinforcing strands. The smooth-surfaced, vesicular, expanded perlite is unique and novel.
    Type: Grant
    Filed: August 24, 1990
    Date of Patent: May 19, 1992
    Assignee: Advanced Concrete Technology, Inc.
    Inventors: David A. Smetana, R. Steve Williams