Concrete does not want to be a beam, it wants to be an arch. Reintroducing funicular geometry for spanning space in concrete makes it possible to significantly reduce the amount of material needed, but also, because of the very low stresses, build with lesser emitting materials. Recent developments in computational design and engineering methods and construction-scale digital fabrication now allow us to introduce concrete as an extremely sustainable solution for common structural elements like a floor “slabs” or a arched bridges. This lecture will introduce how we can disrupt concrete construction: lightweight, extremely low embodied emissions, no embedded reinforcement steel, using very little resources and made largely out of construction demolition waste, fire resistant, providing thermal mass, acoustically performant, dry-assembled prefab, so easily demountable and reusable as structural components or entirely and easily recyclable at the end of its life, available at scale and globally, and economic. Sounds too good to be true?