Every evening, Wilmington daily commercial., 1906-01-24

Tho nroposed new building ordinance,
ending in City Council, contains
nO" rsoulations concerning the future
T.rneiion of walls for buildings in
ms city IN the future. Under 1t the re-
.,s5 thickness of all concrete walls or
S-'rrooGne or floor construction is for
A.. INN thickness of the material only,
exclusive Of the phstering or floor bal
hstine
mont and mcombustible and fire and
a,tcr proof material may be used as a
,nh.titute for any natural stone, but no
srtifeia stone containing more than iif-
s''n NOR cent of lime or crushed lime ds
an INGREDIENT can be used in a Intel or
bs,rinr part in any building over five
Portland building blocks with hollow
s,aces not exceeding one third the area
II the block and having an annulus of
uniform thickness, and not exceeding
Nine inches high nor less than eight
inches on the beds may be substituted
for brick in all buildings up TO four
stories provided an eight-inch block shall
bs deemed the equivalent of one brick in
,biekn4ss of measure and that the incre-
r,sri of increase at the thickness is not
h. than four inches for a half-brick
and that no ten-inch block is substituted
for one and one-half brick wall except
in the foundations of a two-story build
Inc not exceeding twenty-five feet in
height without a basement or cellar.
llonohthic concrete walls construct
d i'm place must be of the thickness pre-
sribed for brick built up within plank
framework in tamped one foot layers and
the exposed surfaces must be well wet
nd before adding the next succeeding
hyer All pockets to receive the ends Of
floor beams or ioists and all openings
properly proportioned to receive door and
window frames without cutting shall be
left In the wall as it is carried up. No
Isolated supporting monohthic concrete
pier can be used in the exterior OF in
terror of any building above the base
uent floor level, except as modified for
tussed concrete columns.
Arched concrete is permitted for floors
when built in an arched form, either with
youssoirs or as a monolith, with or with
out reinforcement; slab concrete, when
amorod concrete extends in a homo
. NtNNNNn mass AAWANAA 10 anu ANnAN UNI
iormly on all its supports; Intel con-
crete, when reinforced concrete or when
the reinforcement Of armored concrete is
Of a larger mesh than the thickness pre-
scnbed, OF if the netting or lattice work
is broken with a seam or splice so as TO
break the homogenity or a slab.
TUssed concrete lintels, ioists, beams,
rirders and columns are lintels, ioists,
beams, girders and columns made of re-
enforced concrete, in which the concrete
mixture shall be of such proportions that
It's resistance TO crushing shall not be
less than two thousand pounds per square
inch after hardening twenty-eight days
and the steel reinforcement is of such
shape and so combined with the concrete
that the steel viii take up the tensile
stresses and assist in the resistance tc
shear along proper structural lines so that
4 the internal stresses and resistance OF
the combination can be ascertained bl
computation and verified by tests Truss
ed concrete must be so designed that the
stresses in the concrete and steel can moi
exceed the following limits: Extrem,
lore stress in concrete in compression
5W pounds per square inch; the shearinl
stress in concrete and the adhesion o.
the concrete TO steel, so; concrete in di
rect compression, $50; tensile stress il
steel 10000; compression in steel, 10000
slearlng stress in steel, 10000.
The ratio of moduli of elasticity o
concrete and steel must be one TO fifteen
lhe tensile strength of concrete canno
be considered.
When the shearing stresses DEVELOPS
IN any part of a trussed concrete con
Nmoiion, either vertical or horizontal
exceed the safe working strength of con
crete as fixed in the code, a suflicien
amount of steel, of such shape as q
assure a mechanical bond, shall be in
uoduced in such a position that the de
naeney IN the resistance to shear is over
come provided that all shear member
are nndly secured to the main horizon
'al reinforcing member
When the safe limit of adhesion be
tween the concrete and steel is exceede
tme provision shall be made for trans
mitllng the strength of the steel to tn
concrete.
lhe spacing of the reinforcing rod
nom centre to centre or between tn
neutral axis of other shapes in a trusse
wncete column, cannot be less than on
10 Of the ratio of the least side or d
smeter 10 their clear height The rod
y shapes shall be tied or latticed t,
gelher at intervals not exceeding tn
Nlst side or diameter of the fnishe
.9lumns, and, when so spaced or tie
ue rods or shapes shall be of suficier
Isnelh to take up the super impose
lu When computed as a latticed ste
s. s..ulnn OF similar size and height to q
assembled reinforcing rods or shapes.
Columns composed of structural ste
lapes or bars latticed together bv rive
and filled in solidly and surround,
oy concrete as prescribed. NAV be mr.,
lortioned by assuming that the concre
enclosed within the outer aanoes