UtomoS., and SumarnoA. “he ffect of dditional rystalline aterials on oncrete on ulfic cid”. JIEEB nternational ournal of ntegrated ducation, ngineering and usiness ISSN 2615-1596 ISSN 2615-2312, ol. 4, no. 1, Mar. 2021, pp. 21-31, doi:10.29138/ijieeb.v4i2.1349.