This concrete was made from old seashells that trap water and prevent flooding

Researchers have developed a type of concrete that uses discarded shells. It’s now combating floods and food waste in urban gardens and along cycling paths.

This time of year, bushels of rhubarb, potatoes, and lettuce can be harvested in abundance at the People’s Pantry, a community garden that doubles as a fresh food pantry in Blackpool, England. There, residents living in adjacent affordable housing units tend to the fresh crops they grow and then eat. And lining the ground beneath each raised bed of soil is a smooth sheet of concrete, dotted with slivers of ivory shells.