Standard for Fire Safety in Rapid Transit Systems - Singapore Civil ...

APPENDIX C - continued
PART VIII : PRESTRESSED CONCRETE FLOORS (SILICEOUS OR CALCAREOUS AGGREGATE)
Description 4
hours
Solid slab Average cover to reinforcement
Depth , overall+
Cored slabs in which the cores are circular
or are higher than wide. Not less than 50 %
of the gross across section of the floor
should be solid material
Hollow box section with one or more
longitudinal cavities which are wider than
high
Ribbed floor with hollow infill blocks of
clay , or inverted T-section beams with
hollow infill blocks of concrete or clay. A
floor in which less than 50 % of the gross
cross section is solid material must be
provided with a 15 mm plaster coating on
soffit
Average cover to reinforcement
Thickness under cores
Depth , overall+
Average cover to reinforcement
Thickness of bottom flange
Depth , overall+
Average cover to reinforcement
Width or rib , or beam , at soffit
Depth , overall+
Upright T-section Average bottom cover to reinforcement
Side cover to reinforcement
Least width or downstanding leg
Thickness of flange+
Inverted channel sections with radius at
intersection of soffits with top of leg not
exceeding depth of section
Inverted channel sections or U-sections with
radius at intersection of soffits with top of
leg exceeding dept of section
Average bottom cover to reinforcement
Side cover to reinforcement
Least width or downstanding leg
Thickness at crown+
Average bottom cover to reinforcement
Side cover to reinforcement
Least width or downstanding leg
Thickness at crown+
* Supplementary reinforcement, to hold the concrete cover in position, may be necessary.
+ Non-combustible screeds and finishes may be included in these dimensions.
Minimum dimension
to give fire resistance
in
2
hours
Standard for Fire Safety in Rapid Transit Systems C-10
1
hour
mm mm mm
65*
150
65*
50
190
65*
65
230
65*
125
190
100*
100
250
150
100*
50
125
150
100*
50
110
150
40
125
40
40
160
40
40
180
40
90
160
65*
65
150
125
65*
35
75
125
65*
35
70
125
25
100
25
25
110
25
25
130
25
70
110
40
40
90
100
40
20
45
100
40
20
45
100