Inexpensive Methods of Fireproofing 
this type of construction for dwellings and 
for buildings of similar light nature. 
The principle of reinforced concrete, as 
used for supporting members of a building, 
such as girders, beams, lintels, is based on 
the theory that every simple beam, loaded 
either uniformly over its entire length or 
with the weight concentrated at any point 
thereof, is in compression at the top and in 
tension at the bottom: that is, the tendency 
is for the beam to crush at the top, and to 
pull apart at the bottom. By using steel bars 
of the proper area and at the proper location 
to resist the tension in the beam and arranging 
the concrete so as to resist the compression, 
the stresses in the beam will be in equilibrium: 
or, in other words, the beam will sustain the 
load for which it is designed. 
Furthermore, in reinforced concrete, the 
construction assumes the character of a 
monolith, and by reason of this fact the beam 
is fixed at the ends and a reversal of the strains 
is produced in the beam adjacent to the sup¬ 
ports, so that the tensile forces are not on 
the bottom of the beam for its entire length, 
but near the supports, shift to the top of the 
beam; hence, it is necessary to reinforce this 
top part with steel to prevent the top of the 
Figure IS 
Figure 16 
