Optimum Mix for Pervious Geopolymer Concrete (GEOCRETE) Based on Water Permeability and Compressive StrengthSalaheddin Abdulsalam Arafa, Ahmad Zurisman Mohd Ali, Siti Nazahiyah Rahmat and Yee Loon LeeMATEC Web Conf., 103 (2017) 01024DOI: https://doi.org/10.1051/matecconf/201710301024