Instructions to Inspectors
ON

Reinforced Concrete
Construction

BY

Geo. P. Carver, Concrete Engineer
BEVERLY, MASS.
Copyright 1906 by G. P. Carver

Instructions to Inspectors
ON

Reinforced Concrete
Construction

BY

Geo. P. Carver, Concrete Engineer
BEVERIyY, MASS.

INSTRUCTIONS
Inspectors will be required to become familiar with and carefully follow
out the following instructions regarding
inspection and see that the work is
carried out in strict accordance with
same. An inspector will be required to
be on the work during the setting of
forms, placing of reinforcement and the
mixing and placing of concrete. He
will represent the Engineer-in-Charge,
and will be held responsible for the
correct performance of the work assigned
to him. He will, in a general way,
carefully and continuously watch the
progress of the work, making a record
of the amount of work done each day
and the manner in which it is done.
He will be required to become
thoroughly familiar with the plans of
the work which he is inspecting, that
he may intelligently perform the duties
intrusted to him. He will be required
to fill in a daily report sheet, printed
forms being furnished for this purpose,
giving the location of the work, the
amount of work done, the number of
batches mixed and placed, the proportions used, the arrival of material and
all such other information as will assist
in making a concise and accurate record
of the progress and cost of the whole or
any part of the work. H e will see that
the following specific instructions are
carried o u t :

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«&^> 2^
FORMS
That the forms are properly set up
and braced.
That the concrete face of the forms
are given a coat of oil, applied with a
brush.
That an excess of oil is not used.
That the forms are cleaned at each
setting and re-coated with oil.
That the forms are correctly placed,
allowing the depth, width and batter
called for on the plans.
That the inside of the forms is free
from debris (shavings, sawdust, blocks
of wood, etc.) just previous to pouring.
That the forms are properly held together with No. 9 wire or rods of suitable dimensions, and temporary spacing
pieces are used and removed when the
concrete reaches their height.
That the joints formed by the edges of
the lagging are tight, so that grout will
not escape, and that such defects are
remedied by the use of plaster of paris,
calking, strips of wood or other suitable
approved method.
That the arch centers are lowered
sufficiently to allow the arch ring to
assume its permanent set before spandrel walls are poured, in this manner
reducing the possibilities of cracks occurring in spandrel walls because of
possible excessive settlement in crown
of arch ring.
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STEEL REINFORCEMENT
That the correct number and size of
reinforcing bars are used, and that they
are placed as shown on plan.
That all steel used is free from loose
or scaly rust. (A thin film of rust will
not cause the rejection of a bar.)
That bars covered with loose, scaly
rust are cleaned with a stiff wire brush
or given a pickling bath of a sulphuric
acid solution (consisting of i part acid
to 6 parts of water) and dipped in clean
water.
That the intersection of the rods are
wound with a length of No. 18 wire in a
sufficient number of places so that the
whole steel reinforcement will be fabricated sufficiently strong and rigid to
withstand the placing of concrete about
the steel and without disturbing the
position of same.
That the bars are spaced the proper
distance apart and away from the face
of the form work and are secured properly and held in that position in such a
manner that they will not be disturbed
by the placing of concrete.
That all protruding bars from piers
and arches to which other bars are to be
spliced and which will be exposed to
the action of the weather for an indefinite period are protected from rusting by
a coat of thin, neat cement grout.
That the position of th^ gtfgl, i§ $pt
disturbed during pouring.

P L A C I N G CONCRETE
The inspector will see that the specified proportions of material are used in
mixing the concrete.
That the concrete is of the proper
consistency.
That an accurate account is kept of
the number of batches mixed, the same
to be recorded on a printed card which
will be furnished for that purpose.
That these batch record cards are
preserved and filed for future reference.
That in placing the concrete the same
will be done in a careful manner and
precautions taken not to allow the concrete bucket to come in contact with the
form work.
That care is taken not to jar the form
work until the concrete work is
hardened.
That in making a bond between old
and new work care is taken to thoroughly clean the surface of old concrete
(preferably by a jet of steam), and that
a thin layer of a i to i grout is spread
to assist in making a good bond.
That the surface of the concrete
which is to be bonded to other concrete
is left in a rough condition, either by
spreading a layer of broken stone over
the same, running half the depth of the
stone into the green concrete and leaving the upper half of the stone protruding, or by setting in strips of wood,
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which, when removed, will form a
groove and assist in making a good
bond.
That in bonding the spandrel wall
with the arch ring, a groove or ridge is
formed on arch rings running under and
with spandrel wall to prevent water
from center filling to run through and
down the face of arch ring discoloring
same.
That in placing dry concrete the same
is thoroughly compacted with suitable
approved iron tamps.
That in pouring wet concrete the same
is thoroughly spaded, rodded and
worked with suitable tools sufficiently
to cause all air bubbles to escape,, to
work grout to face of form work filling
all voids and showing a smooth, wellmixed concrete free from voids when
forms are removed.
That a fine mixture of i to 3 is deposited around and among the bars, and
that it is thoroughly worked in and
around the bars in such a manner that
the steel will be completely surrounded,
embedded and covered.
That all concrete is deposited in forms
within 30 minutes after leaving mixer.
That all exposed surfaces of concrete
are kept continually wet for a period of
10 days after removal of forms.
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IN GENBRAI,
A record book will be furnished trie
inspector; in which, a record will be kept
of the progress of the work, and the following information should be recorded :
Date; time of day of each entry ; day
or night work ; number of men ; foreman ; condition of forms ; condition of
steel; number and location of lights (if
night work) and if properly lighted;
number, time and location of test cubes
taken ; rate of mixing; size and number of batches ; proportions of mixture ;
name or number of work barge; arrival
of material; kind and amount and on
what barge.
Inspectors will be required to fill in
several daily report blanks that will be
furnished.
Inspectors will receive further written
instructions from the Engineer-inCharge from time to time, and will attach same to these instructions and will
consider them a part of same.
Care should be taken not to allow the
first concrete placed to appreciably
stiffen or set before the remaining concrete is placed. The remedy for this is
to occasionally, as often as is necessary,
add k little more concrete to that already
placed over all exposed surfaces.
Great attention is necessary to make
each section (pier, arch ring or spandrel
wall) monolthic in height, length and
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width. Only when circumstances render
it practically unavoidable may the work
be stopped before the entire section is
completed.
Order and close attention to details is
essential. Carelessness in proportioning, in mixing or compacting the
materials, or the omission or misplacement of the steel bars, may cause defective or even destructive results. Reinforced concrete construction requires
close, continuous and intelligent supervision.
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