CBCA6. Thermal Analyses based on the software Supertempcalc

The reduction factors of the steel for strength and modulus of elasticity were presented in the Fig. 13. The total emissivity for steel, concrete or masonry was considered as 0.7. The density for masonry and concrete, were considered, respectively, as 1600 and 2300 kg/cm3. It was considered moisture content of 1.5 % of concrete weight; other thermal parameters from EC 2(7), EC 3(8) and OZONE (9).

Column and a 10 cm thick normal brick temperatures (facing one side) were obtained using the software Supertempcalc (10) (for convection, radiation and conduction) with ISO and Natural fires, based on item 5, Fig 12 (Figs. 13 and 15). The equivalent temperature is the uniform temperature that causes the same resistance to normal force (Figs. 14 and 16 and Table 3).

Fig. 13 - Temperature at 30 min on the central

Fig. 14 - Resistance to normal force vs. time

Fig. 14 - Resistance to normal force vs. time on the column with wall, whereNfi,Rd = A fy ky,θ (ISO-Fire).

At 31.5 min the steel temperature that causes the same resistance to a normal force is equivalent to a uniform temperature 382.5 °C (reduction factor equal 0.675).

Table 3 - Equivalent temperature for the column - ISO Fire

Fig. 15 -Temperature at 31.5 min

 Fig. 16 - Normal resistant vs. time

Fig. 16 - Normal resistant vs. time on the column with wall (Natural-Fire).

The temperatures of the beam under the slab (Figs. 17 and 19) were determined by thermal analyses using the software Supertempcalc (convection, radiation and conduction) with ISO and Natural fires. The equivalent temperature is the uniform temperature that causes the same resistance to bending moment (Figs. 18 and 20, and Table 4).

Fig. 17 - Temperature at 30 min

Fig. 17 - Temperature at 30 min on the beam under a slab (ISO-Fire).

Fig. 18 –Resistance to bending moment

Fig. 18 -Resistance to bending moment vs. time on the beam under a slab (ISO-Fire).

Table 4 - Equivalent temperature for the beam - ISO-Fire

Fig. 19 - Temperature at 30 min

Fig. 19 - Temperature at 30 min on the beam under a slab (Natural-Fire).

Fig. 20 – Resistance to bending

Fig. 20 - Resistance to bending vs. time on the beam under a slab (Natural-Fire).

At 27 min the steel temperature that causes the same bending moment resistant is equivalent to a uniform temperature 610 °C (reduction factor equal 0.27).

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