When COVID-19 struck Mexico, Cemex’s response was concrete: The cement giant speedily created prefab facilities to tend the sick. Its “turnkey hospital modules” each contain up to 45 beds and can be built within 15 days, at a cost the company says is 70% lower than traditional construction. The mini-hospitals, in place in 12 cities so far, are outfitted with antibacterial concrete and ultraviolet-light-based air filtration systems to curb the spread of infection. Cemex expects to build far more of them, as Mexico plans to install nearly 300,000 new hospital beds by 2030.