Effect of the addition of organic wastes (cork powder, nut shell, coffee grounds and paper sludge) in clays to obtain expanded lightweight aggregates Carlos Javier Cobo-Ceacero; José Manuel Moreno-Maroto; Marta Guerrero-Martínez; Manuel Uceda-Rodríguez; Ana B. López; Carmen Martínez García; Teresa Cotes-Palomino;