Gypsum is one
of the oldest materials used in construction. The first use of gypsum was
recorded approximately 4700 years ago, during the construction of the Great
Pyramid in Giza, Egypt. Due to its poor water resistance, however, the
use of gypsum is not appropriate for exterior applications. Instead, it
has become one of the most widely used materials for interior applications,
such as drywalls and architectural and decorative details.
Research at Columbia has
led to the development of a cost-effective method to achieve natural stone-line
appearance of gypsum products. An admixture has been developed to control the
setting time and flow properties of plaster without an increase in water
content. This controlled flow
and setting permits the color pigments added to the mixture to spread in a very
natural way that creates patterns found in natural stone. Columbia University
has obtained a patent for this admixture.
The tiles shown
here illustrate a small range of applications made possible with this admixture.
Tiles or panels cast in metal forms with very tight tolerances will fit
so accurately that the joints between adjacent units become very small,
and very level surfaces can be produced with relatively unskilled labor.
