CELLULAR GRAVEL PRODUCED FROM RESIDUAL ALUMINO-SILICATE MATERIALS (FLY ASH, METAKAOLIN, SLAG, AND ALKALINE EARTH ALUMINO-SILICATE GLASS) BY NONCONVENTIONAL TECHNIQUES. revtn. 2023;27(2). Accessed April 27, 2026. http://revtn.ro/index.php/revtn/article/view/417