Figuring the formula – class crunches mortar

Students in Tidewater Community College’s masonry technology class got a first-hand look at historical mortars by testing four samples from the Museum of Bangor Maine, with the intent of determining original mortar properties for re-creation by the museum.

“We were excited about this project because it gave us the chance to apply skills to a real-world problem,” notes Bill Denison, TCC adjunct instructor and materials engineering specialist for Titan America.

**The Thomas A. Hill House in Bangor, Maine.**

The samples, supplied by a relative of student Amy Rines, arrived in the lab resembling simple lumps of concrete. The class needed to determine historical properties by finding the proportioning ratios of four historical landmarks: Eastern Maine Medical Center, Thomas A Hill House, Bangor Water Works and 27 Broad St.

The experiment began with students crushing the samples and placing them in graduated cylinders. Next, they soaked the mortar in acidic solution for three weeks, during which time they stirred the samples to help the materials separate into layers. Finally, the students measured the matter for thickness and proportioning ratios. “After our preparation of the samples, we could measure properties with a great deal of accuracy,” adds Denison.

“This project helped us reach class goals, and now enables the museum to recreate mortars for structure rehabilitation,” says Denison.