The area’s strangest retirement party? Construction industry gathers in Somerville to wish ‘portland cement’ farewell. (ft. Sublime Systems)

This was not your typical retirement party: A bunch of construction industry types gathered at Sublime Systems in Somerville to bid farewell to the most commonly used kind of cement.

Sublime cofounder Leah Ellis wants to replace portland cement with less environmentally intrusive cements, including her company’s. That’s why, when thinking about how to mark the 200th year of portland cement, it made more sense for Sublime to throw a retirement party instead of a birthday or anniversary celebration. So the startup brought together employees and business partners on Oct. 21 at its headquarters at Rafi Properties’s Somernova complex in Somerville, to raise a pint of beer from Aeronaut next door and bid portland cement goodbye.

The manufacturing process behind portland cement emits large amounts of carbon dioxide into the atmosphere, in part because much of that CO2 is trapped in the limestone used to make portland cement, and in part because a coal-fired kiln is cranked to super-high temperatures to heat the limestone. Sublime uses different minerals in its process, and it relies on electricity instead of coal fire — all to vastly reduce the carbon footprint.