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finish to IX applied shall bc as follows:
(rl ( screeded
) .- shall apply to unformed
that are to 1~ covered by backfill or by concretcb and surfaces of
subfloors which will bc cove’red by concrete floor topping.
U1 is also used as tlkc first stagr for Finishes U2 and U3.
produce even uniform
as dcscribcd under 4.16.1 shall not exceed 1 cm ( or ) in ).
U2 (jEo&d $nish) - shall’ apply to unformed
by backfill or concrete or unformed
surfaces for which Finshcs Ul and U3 are not specified, and shall
crete 28 IS : 457 - 1957
include floors. of sumps, tops of walls, parking areas, parapet
walls, sdrfaces of gutters, sitlcwalks :md outside entrance slabs.
Finish U2 is also used as the second stngc for Finish U3.
may be performed by use of hand- or power-driven
shall bc started
as soon as the screeded surface has
stiffened sufficiently, and shall IX, tl:c> minimum necessary to produce a surface that is frc,c from srrcccl marks and is uniform in
If Finish II3 ih to bc al~l~lic~:l,floating shall be continued
until a small amount of mortar \\itllout excess water is brought
to the surface,
so as to permit cffcctivi:
measured as tlcscribcd under 4.16.1 shallkot exceed
O-5 cm ( or $ in ). Joints and etlgcs of gutters, sidewalks, entrance
slabs, and other joints ant! cclgcs shall be tooled where necessary.
c) Finish U3 ( trowelled jinish ) -- shall apply to unformed surfaces,
such as slabs to be covcrtxtl with built-up roofing or membrane
and stair treads.
\Thcn the floated surface has
hardened suf?iciently to prcvcnt exct’ss of fine material from being
drawn to the surface. steel trowelling
shall he started.
trowelling shall be performed with firm pressure, so as to flatten
the sandy texture df the floated surface and produce a dense uniform surface, free from blemishes and trowel marks; light steel
trowelling will be permissible on surfaces of slabs to be covered
with built-up roofing or membrane
in which light
trowel marks are not considered
Surface irregularities measured as described under 4.16.1 shall not exceed 0.5 cm
(or & in). 5. FORMS FOR CONCRETE 5.1 General-Forms
shall I)r usrd whcrcvrr nrcessary to confine conAll exposed conrrtstc surfaces having slopes
crete and shape it as required.
of one to one or stccpcr shall I )t’ formed, u111css othc;rwist~ clirectcd.
the character of the natural material cut into to receive a concrete structure is such that it can be trimmed to the prcscrihed lines, the use of
forms shall not be r:~cluiretl. The forms sl~all Ilave sufficient strength
and rigidity to hold the concrete ant1 to witllstand the nrcessary pressure,
ramming, and vibration Lvithont excessive deflection...
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- Fall '13