A recent article posted on the LiveScience website discusses attempts by a group of researchers to promote a “greener” cement. The researchers at Drexel University (located about 90 minutes’s from Bridge Gap Engineering’s office in the Lehigh Valley) have developed an alkali-activated cement composed of limestone, ground granulate blast-furnace (GGBF) slag, and soda ash. Research performed by the group indicates that a similar mixture may have been used in pouring some components of the pyramids in Egypt. The mix is literally green when poured, and cures to a gray/white finish. The technology has been spun into a new company, Greenstone Technologies, LLC, which is promoting the lower carbon emissions in production, and pushing the material as a greener alternative to OPC.