Fire analysis

Dear all.
I'm modeling insulated RC beam strengthened with NSM  FRP bars under fire exposure.
Usually I apply on the beam the fire in function of time (for two hours of test I set in the first 15 minutes the temperature at 20 Degrees and the following 120 minutes increasing of temperature, ISO 834) and the load in function of time (first 15 minutes a steadly increase of load till the service load and following 120 minutes constant load). In this way I can simuate what I have done during testing:
I applied before the service load to the beam and then I start the fire test.
For testing in which the protection stay in place for all the duration of fire exposure (2 hours) I usually use the following *.DCF.
 
: BY A. PALMIERI
*FILOS
 INITIA
*INPUT
*HEATTR
 BEGIN INITIA
  NONLIN
  TEMPER
 END INITIA
 BEGIN EXECUT
  BEGIN NONLIN
    BEGIN ITERAT
      MAXITE=20
      CONVER TEMPER TOLCON 1.000E-3
    END ITERAT
  END NONLIN
  SIZES  15(540)
 END EXECUT
 BEGIN OUTPUT
   FXPLUS
   FILE "TEMPERATURE B0"
   TEMPER
 END OUTPUT
*NONLIN
  TYPE TRANSI
  BEGIN OUTPUT TABULA APPEND
    DISPLA TOTAL
    STRESS CAUCHY LOCAL INTPNT
  END OUTPUT
 BEGIN OUTPUT FXPLUS
     DISPLA  TOTAL  TRANSL  GLOBAL
:    DISPLA  INCREM  TRANSL  GLOBAL
     FORCE  REACTI  TRANSL  GLOBAL
     STRESS  TOTAL  CAUCHY
:    STRAIN CRACK GREEN
:    STRAIN ELASTI GREEN
:    STRAIN PLASTI GREEN
     STRAIN TOTAL GREEN
:    STRESS TRACTI
BEGIN SELECT
      STEPS 1(1) 2-540(4)  
END SELECT
  END OUTPUT  
BEGIN EXECUT
   TIME STEPS EXPLIC SIZE 15(540)
   BEGIN ITERAT
   METHOD CONSTA
   MAXITE=200
   LINESE
   BEGIN CONVER
     ENERGY CONTIN TOLCON 1E-2
     FORCE  OFF
     DISPLA CONTIN TOLCON 1E-2
  END CONVER
 END ITERAT
SOLVE  PARDIS  MAXTHR 8
END EXECUT
*END
Apparently is working
I have some specimens in which at certain time (e.g. after 60 minutes) part of the insulated protection detach from the beam. I would like to work in phased analysis, but I do not have any idea how can I apply the load and temperature in function of time in combination with the phased analysis.
Can someone help me??
Thanks in advance for the suggestions
Looking forward to hearing from you.