Environmental aspects and renewable energy sources in the production of construction aggregateIzabela Skrzypczak, Wanda Kokoszka, Lidia Buda-Ożóg, Janusz Kogut and Marta SłowikE3S Web Conf., 22 (2017) 00160DOI: https://doi.org/10.1051/e3sconf/20172200160