Specification Part 3 - Road & Bridge Works - Urban Administration ...

602.8.2. At all times sufficient forms shall be used and set to the required alignment for at least
200 m length of pavement immediately in advance of the paving operations, or the anticipated
length of pavement to be laid within the next 24 hrs whichever is more,
602.8.3. Use of guide wires
602.8.3.1. Where slip form paving is proposed, a guide wire shall be provided along both sides of
the slab, Each guide wire shall be at a constant height above and parallel to the required edges of
the slab as described in the contract/drawing within a vertical tolerance of ± 3mrn. Additionally,
one of the wires shall be kept al a constant horizontal distance from the required edge of the
pavement as indicated in the contract/drawing within a lateral tolerance of ± 10 mm.
602.8.3.2. The guide wires shall be supported on stakes not more than 8 mm apart by connectors
capable of fine horizontal and vertical adjustment. The guide wire shall be lensioned on the
stakes so that a 500 gram weight shall produce a deflection of not more than 20 mm when
suspended at the mid point between any pair of stakes. The ends of the guide wires shall be
anchored to fixing point or winch and not on the stakes.
602.8.3.3. The stakes shall be positioned and the connectors maintained at their correct height
and alignment from 12 hours on the day before concreting takes place until 12 hours after
finishing of the concrete. The guide wire shall be erected and tensioned on the connectors at any
section for al least 2 hours before concreting that section.
602.8.3.4. The Contractor shall submit to the Engineer for his approval of line and level, the
stakes and connectors which are ready for use in the length of road to be constructed by 12
hours on the working day before the day of construction of slab. Any deficiencies noted by the
Engineer shall be rectified by the Contractor who shall then re-apply for approval of the affected
stakes. Work shall not proceed until the Engineer has given his approval. It shall be ensured that
the stakes and guide wires are not affected by the construction equipment when concreting is in
progress.
602.9. Construction
602.9.1. General: A systems approach may be adopted for construction of the pavement, and the
Method Statement for carrying out the work, detailing all the activities including indication of timecycle,
equipment, personnel etc., shall be got approved from the Engineer before the
commencement of the work, The above shall include the type, capacity and make of the batching
and mixing plant besides the hauling arrangement and paving equipment. The capacity of paving
equipment, batching plant as well as all the ancillary equipment shall be adequate for a paving
rate of at least 300 m in one day.
602.9.2. Batching and mixing: Batching and mixing of the concrete shall be done at a central
batching and mixing plant with automatic controls, located at a suitable place which takes into
account sufficient space for stockpiling of cement, aggregates and stationary water tanks. This
shall be, however, situated at an approved distance, duly considering the properties of the mix
and the transporting arrangements available with the Contractor.
602.9.3. Equipment for proportioning of materials and paving
602.9.3.1. Proportioning of materials shall be done in the batching plant by weight, each type of
material being weighed separately. The cement from the bulk stock may be weighed separately
from the aggregates and water shall be measured by volume. Wherever properly graded
aggregate of uniform quality cannot be maintained as envisaged in the mix design, the grading of
aggregates shall be controlled by appropriate blending techniques. The capacity of batching and
mixing plant shall be at least 25 per cent higher than the proposed capacity of the laying/paving
equipment.