METHOD OF DETERMINING COEFFICIENT OF EFFECTIVE THERMAL CONDUCTIVITY OF FOAMED CONCRETE

摘要

FIELD: physics.;SUBSTANCE: heat current is applied onto the surface of a test specimen and temperature drop is measured on the surface of the test specimen. For each test specimen, percentage content of main chemical elements of Portland cement SiO₂, AI₂O₃, Fe₂O₃, CaO, is determined, and the pore volume V_B is determined for foamed concrete. The coefficient of effective thermal conductivity of the foamed concrete is then calculated using the formula: λ_ef=((4.2·SiO₂-15.45·Al₂O₃-7.95·Fe₂O₃+1.06·CaO)/100)·(1-V_B)+(0.024+5.25·d)·V_B, where λ_ef is the coefficient of effective thermal conductivity of foamed concrete, W/(m·K); SiO₂ is the percentage content of silicon dioxide, %; Al₂O₃ is the percentage content of aluminium oxide, %; Fe₂O₃ is the percentage content of iron oxide, %; CaO is the percentage content of calcium oxide, %; V_B is the volume pores in the foamed concrete, conducting the heat current; d is the average diametre of pores in the structure of the foamed concrete.;EFFECT: simpler method of determining the coefficient of effective thermal conductivity of foamed concrete.;2 tbl