DARPA seeks underwater 3D-printed concrete to repair and build military ports

DARPA announced a new research challenge aimed at enabling 3D-printing of concrete beneath the ocean surface to support critical military port infrastructure. Participants are asked to devise solutions that use seawater, seafloor sand and clay, and sophisticated maritime construction tools to operate in waters as deep as 100 meters. The ultimate objective is a completely autonomous system that can build or repair ports, seawalls, artificial reefs, and provide blowout protection for undersea oil-gas pipelines and telecommunications cables, guided by AI that selects the optimal sediment-water blend for each site.

Current underwater concrete methods are considered too cumbersome, expensive, and harmful to the environment for expeditionary use. The program follows earlier DARPA work on AI-optimized concrete mixes and a University of Colorado project funded with $10 million to develop self-healing concrete inspired by biological vascular networks. Improving underwater construction could give U.S. forces a strategic edge in future conflicts and address the deteriorating condition of many maritime facilities.