Researchers in Bari, Italy, are turning two costly waste products into a new construction material. Mussel shells from local seafood businesses and sediment dredged from harbors are being combined to create a bio-friendly cement. The project aims to reduce waste, lower disposal costs and provide a more sustainable source of calcium carbonate, a key ingredient in cement production. Three Mediterranean ports plan to test the material for breakwaters, paving and other infrastructure, giving new value to materials that would otherwise be discarded.