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Method for Improving the Strength of Macro Defect-Free Cements

IP.com Disclosure Number: IPCOM000119702D
Original Publication Date: 1991-Feb-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 2 page(s) / 51K

Publishing Venue

IBM

Related People

Dreyfus, RW: AUTHOR [+3]

Abstract

The strength of Portland and other conventional cementitious materials are known to be increased by curing with microwave radiation 1. Separate from the above procedure, the flexural strength of cements is increased from 5 to 10 mega Pascals into the range of 100 to 160 mega Pascals by rendering them macro defect-free 2. The latter is accomplished by the addition of a polymer (for instance, polyvinyl acetate 85% hydrolyzed, molecular weight 82,000) and mixing the cement with water in a high shear mixer or roll mill. The usual procedure is then to cure this MDF material for 4 to 6 weeks at room temperature or 60@ to 80@ for 12 to 24 hours at pressures of several thousand pounds per square inch.

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Method for Improving the Strength of Macro Defect-Free Cements

      The strength of Portland and other conventional
cementitious materials are known to be increased by curing with
microwave radiation 1.  Separate from the above procedure, the
flexural strength of cements is increased from 5 to 10 mega Pascals
into the range of 100 to 160 mega Pascals by rendering them macro
defect-free 2.  The latter is accomplished by the addition of a
polymer (for instance, polyvinyl acetate 85% hydrolyzed, molecular
weight 82,000) and mixing the cement with water in a high shear mixer
or roll mill.  The usual procedure is then to cure this MDF material
for 4 to 6 weeks at room temperature or 60@ to 80@ for 12 to
24 hours at pressures of several thousand pounds per square inch.

      The present work describes a technique to further increase the
flexural strength of cementitious materials by combining the above
techniques.  In addition, it is described how not only microwave
energy (at 2.45 gigahertz frequency) produces the enhanced strength,
but also intense electromagnetic energy in the infrared optical
region produces the increased strength.  This latter energy is
supplied by a neodymium-YAG (yttrium aluminum garnet) laser operating
at 1.06 micrometer wavelength.  The positioning of the sample for the
laser irradiation is shown in the figure. 1 is the (previously
ambient or warm air-cured) cementitious wafer, 2 to 4 mm thick.  2 is
the laser beam.  The laser beam is a...