Tender Document - irpmu.railnet.gov.in

18.6 Wherever chamfer or rounded corners are mentioned in the drawing formwork,
should be such that no chiselling/ cutting is required. The surface of formwork
should be clear, smooth and free of cement mortar.
18.7 The Contractor shall give the Engineer In-charge sufficient notice in advance
before placing any concrete in the forms to permit him to inspect and accept the
false work and forms as to their strength, alignment and general fitness but such
inspection shall not relieve the contractor of his responsibility for safety of works,
men, machinery, materials and for result obtained.
19.0 REMOVAL OF FORM WORK:
19.1 The Engineer-In-Charge shall be informed in advance by the contractor of his
intention While fixing the time for removal of form work, due consideration shall be
given to the local conditions, character of the structure, the weather and the other
conditions that influence the setting of concrete and of the material used in the
mixes to strike any formwork.
19.2 The period shall be suitably increased in case of temperature lower than 25
degree Celsius and for any other conditions tending to delay the setting of
concrete.
19.3 These field operation are controlled by strength tests of concrete. The removal of
the load supporting arrangements of soffit may commence when concrete has
attained 70% characteristic strength, at the time of striking props including the
effect of any further additions of loads. When field operations are not controlled by
strength, test of the concrete, the vertical forms of beams, columns & walls may
be removed as per orders of the Engineer- In-charge.
19.4 For pre-stressed units the side forms shall be released as early as possible after
12 hours of casting and so fit forms shall be permitted without restraint
deformation of the member when pre-stressed is applied.
19.5 All formwork shall be removed without causing any damage to be concrete.
Centring shall be gradually and uniformly lowered in such a manner as to avoid
any shock or vibrations. Supports shall be removed in such a manner as to
permit concrete to take stress due to its own weight uniformly and gradually.
Where internal metal ties are permitted, their removable parts shall be extracted
without causing any damage to the concrete and the remaining holes filled with
mortar. No permanently embedded metal parts shall have less than 40mm cover
to the finished concrete surfaces, where it is intended to re-use released form
work, it shall be cleaned and make good to the satisfaction of Engineer-incharge.
20.0 MEASUREMENT:
20.1 All work will be paid for at the tendered rates on the basis of actual
measurements taken at site. Individual rate for each non-schedule item should
be fore complete finished work, inclusive of all operational charges. Nothing extra
will be payable on any account.
OS/Works 54