Precast Concrete Models Fabricated with Big Area Additive Manufacturing

The traditional process of making precast concrete molds requires significant manual labor. The molds are made using hardwood, cost tens of thousands of dollars, and take weeks to build. Once built, a mold will last 5-10 pulls before becoming too heavily degraded to continue use. With additive manufacturing, the same mold can be built in eight hours, post-machined in eight hours, costs about $9000, and is projected to last nearly 200 pulls. Oak Ridge National Laboratory has been working with Big Area Additive Manufacturing (BAAM) to fabricate concrete molds for a new high-rise apartment complex in New York. The molded pieces will form structural window supports for the hundreds of windows in building façade. The magnitude of window molds is where additive manufacturing can shine when producing the geometry. This paper will discuss the methods and findings of using BAAM to replace conventional precast concrete pattern making.