Problem $2-$ Fire analysis of a RC slab

A simply supported slab, $200mm$ thick, spans $7m$ and is made with carbonate aggregate

concrete having compressive strength of $40$MPa and steel yield strength of $400$MPa. The

density of concrete is $2400k\frac{g}{m^3}$ and the cover to bottom rebars is $25mm.$ The dead $($excluding

self weight$)$ and live loads on the slab are $1k\frac{N}{m}$ and $2k\frac{N}{m},$ respectively. The slab is exposed

to ASTM E$-119$ fire exposure. Using Wickstrom's method for calculating the temperatures on

ONE graph in rebars and concrete.

$($a$)$ Plot the temperatures in rebars, and in concrete: at the top surface and at $75mm$ depth.

$($b$)$ Calculate the flexural capacity of the slab after $90$ minutes.

$($c$)$ Check the fire resistance of the RC slab using generic ratings $($simplified approaches$).$

$($d$)$ Calculate the load ratio of the slab.

$($e$)$ Describe in words what would be different if the slab is continuous over the beams.