TY JOUR TI POSSIBILITY OF USING BOTTOM ASH FOR MANUFACTURING BUILDING MATERIALS IN VIETNAM KW industrial wastes KW environmental pollution KW fly ash KW ash residues KW cement-sand stone KW compressive strength KW activity index JO Bulletin of Belgorod State Technological University named after. V. G. Shukhov AU Tang, V.L. AU Bulgakov, B.I. AU Aleksandrova, O.V. AU Larsen, O.A. PY 2017 IS 2 PB Belgorod State Technological University named after V.G. Shukhov