TY JOUR TI CEMENT FLAX HARDS MODIFIED WITH HYDROACTIVE POLYURETHANE KW Portland cement KW flax shive KW liquid sodium glass KW polyurethane KW sodium phosphate KW thermal conductivity KW porousness JO Technique and technology of silicates AU Yakovlev, G.I. AU Ginchitskaya, Y.N. AU Neretina, D.D. AU Kuzmina, N.V. AU Plekhanova, T.A. AU Gilyachev, I.G. AU Al-Rifai, A.A. PY 2026 IS 33 PB Individual Entrepreneur Svetlana Vasilievna Samchenko