Quality Assurance Handbook for Rural Roads Volume-I - pmgsy

3. Section-1900
4. Remove any damaged portions at the edges, replace by fresh material and roll.
5. Any corrugated surface formed by excess blindage material should be rectified by removing all
excess blindage material by dragging or brooming. Where corrugations develop in WBM course
itself, a renewal layer of WBM will be required.
6. Fine hair cracks on the surface are usually indicative of ravelling taking place later. This tendency
for ravelling can be remedied by blending with good binding material and watering the surface.
Where ravelling has developed prominently, resurfacing should be carried out.
II. Periodic Surface Renewal
Where the condition survey data reveals the need for surface renewal, provide a 75 mm thick
layer of WBM grading 3 as per Sub-section 405. Prior to laying a surface renewal, clean the existing
surface of all dust and caked mud by wire brushes and brooms. After light sprinkling of water,
scarify the surface and screen the salvaged materials to be used later, if found suitable. The salvaged
material together with fresh additional material should be spread and dry rolled followed by
application of screenings and binding material, and wet rolling as per Sub-section 405.
B. Quality Control Requirements
1. Materials
The quality of stone aggregates, screenings and binding material used for routine maintenance as
well as periodic surface renewal should conform to the requirements laid down in Subsection 405
for WBM construction.
2. Surface Finish
The surface finish requirements after carrying out various maintenance measures should also
conform to the surface finish requirements laid down in Subsection 405.
3. Camber/Crossfall
Camber/Crossfall should be checked for ensuring conformance with the specified requirements.
C. Do’s and Don’ts
Do’s Don’ts
1. Make sure that all materials used in maintenance
repairs i.e., coarse aggregates screenings and binding
material meet the quality requirements laid down
in Subsection 405.
2. While filling potholes, keep the surface slightly
proud of the surrounding area.
3. While repairing damaged portions of edges, rolling
of the edge and shoulder should be carried out
simultaneously and the cross profile of the shoulder
remedied by grading.
4. After providing surface renewal, a 6 mm layer of
coarse sand should be provided and lightly sprinkled
with water.
1. Do not use the salvaged material for repairs, if these
do not meet all the quality requirements.
2. Do not ignore the presence of fine hairline cracks on
WBM surface as these are indicative of serious ravelling
to occur later.
3. Do not provide resurfacing unless the old surface has
been scarified.
4. Do not allow traffic immediately after laying the WBM
surface renewal.
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