A cylindrical stone mix concrete beam of diameter D 0.5 m initially at Ti=20 C is exposed to hot gases at T=500 C. The convection coefficient is h=10 W/m2 K.
(a) Determine the centerline temperature of the beamafter an exposure time of t =6 h.
(b) Determine the centerline temperature of a second beam that is of the same size and exposed to the same conditions as in part (a) but fabricated of lightweight aggregate concrete with density = 1495 kg/m3, thermal conductivity k =0.789 W/mK, and specific heat cp = 880 J/kg K.