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RC construction must be reinforced to make it safe
when they become danger because of fire, damage of material
and load alter etc. Methods of reinforcement include
altering construction system and reinforcing strength
of construction component, such as beams and columns.
On altering construction system, methods of adding
walls, declining shore, and columns alter load system
as a whole. Thus, construction system load is shared
to make old construction reinforced.
On reinforcing strength of construction component,
reinforcement of steel plates (or FRP etc.) is a method
in common use. Commonly, altering construction system
is a economical, effectual method if the method don't
change function of old construction. However, the method
can generally damage function of old construction. Thus,
the method is difficult to use effectually.
The method, reinforcing strength of construction component,
is not economical, but it is a popular method when we
consider benefit as a whole (function is more important
than reinforcement cost).
The reinforcement method of construction component
includes steel plates (or FRP) reinforcement and enlarging
section and bar of members. When we use the method of
enlarging section and bar of members, we should consider
the ways of operation of interface between new and old
concrete and bar's joint and fixation. The effect of
operation can be evaluated by current RC theory. So,
we can gain our ends for construction reinforcement.
However, enlarging section of members will reduce active
space. It is difficult to accept the method because
it is so expensive to buy a block of land or house in
modern city. Thus, the method of steel plates (or FRP)
reinforcement is more popular than that.
When we reinforce RC construction with steel plates,
we should affix steel plates on two sides of beams with
epoxy resin and anchor them at appropriate point with
bolts to form sandwich beams. The bend theory of the
sandwich beams display that the method of affixing steel
plates on two sides of beams can reinforce moment and
shear of old RC beams.
According to theory above and experimental result,
this paper present a simple and effectual design table
and design method to be adopted by construction engineers
when they make some designs for reinforcement of RC
beams.
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Reinforcement with H-profiled
steel when usages of building change or more structure
strength need.
