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

501.8.2.4. Profile corrective course and its application: The type of material for use as profile
corrective course shall be as shown on the approved drawings or as directed by the Engineer in
charge. Where it is to be laid as part of the overlay/strengthening course, the profile corrective
course material shall be of the same specification as that of the overlay/ strengthening course.
However, if provided as a separate layer, it shall be of the specification and details given in the
approved drawings.
(i)Any high spots in the existing surface shall be removed by a milling machine or other approved
method, and all loose material shall be removed to the satisfaction of the
Engineer
(ii)Where the maximum thickness of profile corrective course will be not more than 40 mm, the
profile corrective course shall be constructed as an integral part of the overlay course. In other
cases, the profile corrective course shall be constructed as a separate layer, adopting such
construction procedures and using such equipment as approved by the Engineer in charge, to lay
the specified type of material, to thickness and tolerance as specified, for the course, to be
provided.
501.8.3. Construction Operations
501.8.3.1. Preparing existing granular surface:
(i) All loose materials shall be removed from existing granular surface.
(ii)The existing granular surface shall be lightly watered where the profile corrective course to be
provided as a separate layer is also granular.
(iii)Where the profile corrective course of bituminous material is to be laid over the existing
granular surface, the existing granular surface shall be primed, after removal of all loose material.
(iv)The surface finish of all granular layers on which bituminous works are to be placed, shall be
free form dust. All such layers must be capable of being swept, after the removal of any non -
integral loose material, by means of a mechanical broom, without shedding significant quantities
of material and dust removed by air jet, washing, or other means approved by the Engineer in
charge. After cleaning the surface shall be correct to line and level, within the tolerances specified
for base course.
501.8.3.2. Scarifying existing bituminous surface: Where required, the existing bituminous
layer in the specified width shall be removed with care and without causing undue disturbance to
the underlying layer, by a suitable method approved by the Engineer in charge. After removal, all
loose and disintegrated material, the underlying layers which might have been disturbed should
be suitably reworked and compacted to line and level. After supplementing the base material as
necessary with suitable fresh stone, the compacted finished surface shall be primed in
accordance with Clause 502. Reusable materials shall be stacked as directed by the Engineer in
charge within one kilometer of their origin.
501.8.3.3. Patching of potholes and sealing of cracks: shall be done as per clause 501.8.2.2.
501.8.3.4. Laying the profile corrective course
501.8.3.4.1. Laying on granular base: After preparing the granular surface in accordance with
Clauses 501.8.3.1 and 501.8.3.2, the profile corrective course shall be laid using material as
described in Clauses 501.8.2.3 and 501.8.2.4, or as otherwise described in the Contract, and
compacted to the requirements of the particular Specification.
501.8.3.4.2. Laying on existing bituminous surface: The existing bituminous surface shall be
prepared in accordance with Clause 501.8.3.3, and after applying a tack coat conforming to
Clause 503, the bituminous profile corrective course shall be laid and compacted to the
requirements of the particular Specification.
501.8.3.4.3. Correction of local depressions: Where local sags or depressions occur in the
existing pavement, a specific filling operation shall be instructed by the Engineer in charge.