Le, T.T.T., Mai, M.T.H., Le Sy Chinh, L.S.C. and Nguyen Van Lam, N.V.L. PROPERTIES OF MORTARS USING SPENT COFFEE GROUNDS TO REPLACE A PART OF NATURAL RIVER SAND. Hong Duc University Journal of Science. 79, 09. DOI:https://doi.org/10.70117/hdujs.79.09.2025.965.