Cpnstruction disruptions now are seen, including component shipments to North America, delays on China Belt and Road megaproject, halted industry travel in Europe and respirator mask shortages.

When President Trump said on March 1 that he would impose tariffs of 25% on foreign steel and 10% on aluminum, it immediately put construction estimators and executives, and the suppliers they rely on, into a holding pattern.

Trump must decide by mid-April whether to adopt Commerce Dept.'s proposed stiff penalties.

The nascent 3D-printing industry is working toward the goal of printing large-scale structures with specially designed feed material, but researchers working at a smaller scale are currently exploring techniques for printing a wide range of materials in complex shapes.