Review on Various Types of Geopolymer Materials with the Environmental Impact AssessmentHariz Zain, Mohd Mustafa Al Bakri Abdullah, Kamarudin Hussin, Nurliyana Ariffin and Ridho BayuajiMATEC Web Conf., 97 (2017) 01021DOI: https://doi.org/10.1051/matecconf/20179701021