Volume-IF - JantERmantER

DCPL-K9A01
Vibration shall begin as soon as one batch 0( concrete has been placed and
shalf continue tin the entire section being poured has been thoroughly
consolidated.
To secure even and dense surfaces, free from aggregate pockets, vibration
shan be supplemented by tamping or rodding by hand in the comers of forms
and along the form surfaces whllelhe c:oncrele Is plastic, without damaging
or endangering the stabUity 0( the formwork.
A suffICient number of spare vibrators Including petrol vibrators shall be kept
reedily accessible to the place 0( deposition of the concrete to assure
adequate vibration In case 0( breakdown of those in use.
3.1.6 CurI/Ig of Concrete
Curing 0( exposed surface 0( concrete shaU commence immediately after the
concrete has. set. Exposed sides shall be covered with canvas etc.
immediately afieF ·sltlpping 0( forms, and curing shall be continued for a
period 0( not less than 14 days. reckoned from the date and hour 0(
completion of concreting.' All surfaces of the. pour shaD be kept wet with
water at all times after concreting and lUI the curing period Is over. The
Contracior shaD plan and employ proper equipment and sufficient labour
considered adequate by the Engineer under able supervisor for curing.
3.1.7 Construction Joints
In concreting the chimney shell one full ring lift shall be completed in a day's ,
pour. Before the forrnwork for the following pour starts the horizontal surface
of the Chimney shell shall be chipped, cleaned and washed with water, and
when the forrnwork Is complete, the surface shall be cleaned and washed
again and covered with 1:2 sand cement slurry before fresh concrete is
plaoed. The horizontal construction joints shall be so arranged and made
that, they are regular and neat. No vertical joint shall be allowed. No
separate paYment shaU be allowed to the Contrador for forming JOints or
chipping and cleaning them or cover with slurry prior to concreting. The
nlimber ofCX)nstruction joint shall be kept minimum and the spacing should
not exceed three (3) melers. The Conlractor shall submit to the Engineer,
any proposai of ·providing constflJllllon Joints to facilitate his work, for .the
study end approval of the Engineer well In adVance. ".
3.1.8 Ordinary Concrete
Ordinary concrete Ilke lean concrete shall be of nominal mix as per relevant
cl8I!ses 0( 15:456.
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