Born in Olavarría, Gamondi played football for local side Club Ferrocarril Sud.
The 1926 discovery of large limestone deposits at the San Jacinto Estancia inherited from his father led Fortabat to open a cement factory in the nearby pampas hamlet of Loma Negra (south of Olavarría); the choice of location prompted him to christen the company Loma Negra ("Black Mound").
Later in the 1950s branches were opened between Olavarria and Loma Negra (17 km) and between Tcnl Miñana and Azul (30 km), making a total rail network of 902 km.