BC9

Question 1

alloyed steel

Answer 1

iron and carbon
structural steel has less than 3/10ths percent iron
cast has 3-4 percent

Question 2

basic properties of steel

Answer 2

strongest of common materials
non rotting, dimensionally stable and resistant to aging
relatively expensive but able to be used in smaller quantities

Question 3

to fight rust steel can be

Answer 3

painted with rust inhibiting paint
coated with zinc and aluminum
adding alloys -
molybdenum-adds strength
vanadium- strength and toughness
manganese- resistance to steel abrasion

Question 4

rolling steel

Answer 4

steel ingots must be heated to 2200 degrees

Question 5

expansion of steel

Answer 5

20 foot member can expand 1.4 inches

Question 6

most significant characteristic to the fire service

Answer 6

the deterioration of steel strength at elevated temperatures

Question 7

yield point of steel

Answer 7

1000 F
fire of 1200 can make it reach yield point

Question 8

fire protection of steel

Answer 8

steel framework encased in brick or concrete.
3 inches of concrete and silicons aggregate provides 4 hours of fire protection

Question 9

spray applied fire resistive materials (SFRMs)

Answer 9

efficient and inexpensive
mineral fiber or expanded aggregate coating such as vermiculite or perlite

Question 10

fire resistive coating thickness

Answer 10

7/8 to 1 7/8 provides 4 hours
not suitable for exterior use unless density is greater than 20lb/sq ft
high density SFRMs that use magnesium oxychloride have densities from 40-80

Question 11

cementitious materials

Answer 11

densities from 15-50lbs/sq ft
portland cement
gypsum
perlite
vermiculite

Question 12

gypsum

Answer 12

20% water
1-4 hour protection

Question 13

intutumescent coating

Answer 13

applied as paint .3-.4 inches
expands 15-30 times its Origional volume when heated
chars and foams when heated

Question 14

membrane ceiling

Answer 14

mineral or gypsum
1-3 hour rating
whole assembly is rated together, not just the ceiling

Question 15

delta trusses

Answer 15

three dimensional space frames

Question 16

streel trusses

Answer 16

joist girder or open web joist
open web joists- depth up to 6 ft and 144 ft long most frequently depths less than 2 ft 40 ft long

Question 17

steel arches

Answer 17

gymnasiums and convention centers
can span more than 300ft

Question 18

steel columns

Answer 18

hollow cylinder
rectangular tube
wide flange similar to I beam

Question 19

slenderness ratio

Answer 19

steel is 120.
higher the number higher the rate of buckling
how ends are attached plays role
those with ability to rotate have higher chance of buckling

Question 20

open web joists

Answer 20

floor deign in steel buildings with lightweight concrete 2 inches thick
supported by open web steel joists

Question 21

steel joists

Answer 21

depths of 6-12 inches and spaced 16-48 inches apart