The works mentioned in this Section shall apply to maintenance of road and shall be carried out manually or by machinery in such a way that the quality of end product meets the specified requirements.
Whenever the Specification is not clear, good engineering practice shall be applied to the satisfaction of the consulting engineer.
This Section does not apply to the works as specified for Maintenance of Road during Construction and Defects Liability Period.
Restoration of Road Cuts
The work shall consist of restoration of rain cuts in embankment slopes. The material to be used in the restoration shall be the suitable material conforming to specifications.
The affected area shall be cleared of all loose materials and benched to a width of about 300 mm. The height of the bench shall vary according to the slope of the embankment. Suitable material shall be deposited in layers not exceeding 150 mm and shall be watered/dried as required and compacted using suitable tools or hand compactor. The final slope and top surface after completion of the filling shall match with the adjacent slope and surface of the embankment.
Maintenance of Earthen Shoulders
The work shall include making up of irregularities on the shoulders to the required level and crossfall by adding suitable materials or stripping excess materials and compacting it.
Wherever material is required to be added, the earthen shoulder shall be stripped and loosened up to 100mm depth measured from the existing ground level. The deficiency of thickness shall be made up with suitable material in layers of loose thickness not exceeding 150 mm.
Water shall be added, if required and thoroughly compacted with appropriate equipment to obtain at least 95 % of the MOD in accordance with IS 2720 Part 8.
Wherever the material from the shoulder is required to be excavated, this shall be done by manual means using hand tools or appropriate equipment as directed by the Engineer and shall be compacted, to the 95% of the MDD.
The final surface formed either by addition or excavation of materials shall be uniform, with the cross slope towards the edge of the road width. The top surface along the inner edge of the shoulder shall be flushed with that of the adjacent carriageway.
Maintenance of Gravel Shoulders and Gravel Carriageway
The road maintenance works shall involve repairing of pot holes and making up of irregularities/loss of materials by adding fresh gravel and/or stripping excess gravel from the surface.
Gravel shall comply with the requirements of specifications for gravel wearing course.
Pothole Repair
Each pothole shall be inspected and all loose material shall be removed.
The area shall be cut down to the subgrade level in a rectangular shape.
Edges shall be cut vertically.
The subgrade shall be cleared of all loose materials and hand compacted.
Fresh gravel shall be placed in the pit in layers not exceeding 150 mm and the gravel shall be brought to optimum moisture content and well compacted with small rollers or other equipment as directed by the Engineer.
The resulting surface shall match with adjacent surface.
Shoulder/Carriageway Repair
The work shall involve:
(a) Making up the irregularities/loss of material by adding suitable gravel and compacting the same; and/or
(b) Stripping extra gravel from the surface to achieve the required grade and level.
Wherever extra gravel is required to be added, the existing surface shall be loosened up to 100mm depth to receive fresh gravel.
The deficiency of thickness shall be corrected by adding suitable gravel in layer of 100 mm.
Gravel shall be brought to optimum moisture content and thoroughly compacted using roller/compactor to achieve the density as specified.
Wherever the existing gravel is required to be excavated, this shall be done manually or using equipment like grader.
The resulting surface shall then be watered, if required, and thoroughly compacted to achieve the density as specified.
Finished surface shall have the specified line, level and cross slope. Straight edges shall be used to check the profiles.
BITUMINOUS PATCH WORKS
This Clause covers the repair of the potholes and the damaged bituminous surface.
(1) Excavation
The area to be repaired shall be marked out in square or rectangular shape, 30mm beyond the extent of the damaged area and shall be excavated with all sides vertical up to required depth.
If the existing road base is damaged, it shall be also excavated to a depth required and removed as directed by the Engineer.
(2) Bituminous Patching
(a) Shallow Patching
Shallow patching shall consist of repairs to the carriageway surface to a depth not exceeding 40mm.
Surface of the excavated area shall be swept clean of dust and other loose materials and shall be primed with MC 30 cutback bitumen.
The sides shall also be tacked/primed with cut back bitumen using brush.
The excavated area shall, then, be filled with hot or cold premix material. The premix shall have a net bitumen content of 5% to 6% by weight as directed by the Engineer or as per design mix.
The premix shall then be compacted using equipment approved by the consulting engineer.
After compaction, the surface of the patched area shall be true to the lines and levels of the surrounding existing surface.
(b) Deep Patching
Deep patching shall consist of repairs to the carriageway surface to a depth exceeding 40mm.
The surfacing and underlying courses shall be cut out in square or rectangular shape with vertical sides and to the extent and depth specified by the Engineer.
Excavated hole shall be swept clean of dust and all other loose material.
The excavated area in base and subbase shall be filled with approved materials complying with the requirements of base or subbase, as
applicable, conforming to specifications and shall be compacted in layers not exceeding 100 mm thickness or as directed by the Engineer.
The surface of the compacted base shall be primed with MC 30 cutback bitumen and filled with hot or cold premix material and compacted as described in shallow patching.
After compaction, the surface of the patched area shall be true to the lines and levels of the surrounding existing surface.
(c) Carriageway Edge Repair
Where loss of bituminous surfacing exist at the edge of the carriageway without damaging the base edge repair shall be performed as described for shallow patching.
Where damage of the edge extends into the base/subbase, the edge repair shall generally be carried out as specified for deep patching.
Excavation shall be to a minimum width of 750 mm covering not less than 200 mm of the carriageway and not loose less than 500 mm of the shoulder.
The depth of excavation shall be as directed by the Engineer.
The excavated area shall be filled with base and/or subbase material to a level 40 mm of below the existing level of the road and compacted as mentioned in deep patching.
The surface of compacted base and sides of the excavated area shall be primed/tacked with MC 30 cut back to a line 100 mm beyond that of the deep excavation and excavated area shall be filled with hot or cold premix material and compacted as specified for the shallow patching.
The final surface shall match with the adjacent surface in line and levels.
Road Maintenance With Slurry Seal
This section covers the materials, methods of construction and requirements for the maintenance works with slurry seal.
Slurry seal shall generally be required in the pretreatment of the pavement surface distress such as cracks, raveling etc.
(a) Stockpiling of Aggregates
Sites for the stockpilling of aggregates shall be prepared in such a manner that no grass, mud, soil, dust or other deleterious material will
be included when the aggregates are loaded for use.
(b) Bituminous Binders
The binder shall be K3-60 slow setting bitumen emulsion or as agreed by the Engineer.
Types of Slurry Seal
According to nature and severity of the distress, three types of slurry seal will be applicable.
- Fine Slurry Seal
- General Slurry Seal
- Coarse Slurry Seal
General slurry seal shall be applicable in porous and cracked road surfaces, whereas fine slurry seal shall be used in case of narrowly cracked road surface.
For widely cracked and raveled surface, coarse slurry seal with max. aggregate size of 10mm shall be used.
Fine Slurry Seal
A mix, as detailed below will cover approximately 205 sq.m of road.
- Aggregate 1 cu.m. (bulk)
- Emulsion 250 liters
- Cement 17 kg
- Water as required
The grading of the aggregate shall be as per specification.
General Slurry Seal Mix
A mix, as detailed below, will cover approximately 180 sq.m. of road.
- Aggregate 1 cu.m. (bulk)
- Emulsion 250 liters
- Cement 17 kg
- Water as required
The grading of the aggregate shall be as per specifications.
Coarse Slurry Seal Mix
A mix, as detailed below will cover approximately 150 sq.m. of road.
- Aggregate 1 cu.m. (bulk)
- Emulsion 250 liters
- Cement 17 kg
- Water as required
The grading of the aggregate shall be as per specifications.
Maximum batch sizes for each slurry seal mixes will be in the order of 20 kg.
Daily records of consumption of materials and of areas covered shall be kept and agreed with the Engineer.
Equipment and Mixing
(a) Sufficient equipment for handling and hauling aggregate and binder shall be used in order to ensure prompt and continuous covering of bituminous slurry seals as specified.
All the necessary ancillary equipment and hand tools to carry out the work efficiently shall be available.
(b) In general a rotary type concrete mixer will be suitable to prepare slurry seal mix at the site itself unless otherwise alternative arrangement made by the Contractor to the satisfaction of the Engineer.
The concrete mixer may be mounted at the back of a flat bottom truck which is also loaded with stock of materials (aggregate, emulsion,
cement) for slurry seal mix. Measured quantities of material to prepare a batch of slurry seal mix shall be poured into the drum of the
concrete mixture which shall then be rotated manually till an uniform mix of slurry seal is formed. The time of mixing shall be carefully
controlled.
Over mixing shall not be allowed as stripping of the bituminous film from the aggregate will occur.
The slurry seal mix shall then be discharged over the road surface prepared as mentioned below.
Surface Preparation for Slurry Seal
The road surface shall be broomed and cleaned of all loose or deleterious material by means of rotary broom and hand broom.
A tack coat shall be applied by an approved distributor or manually as directed by the Engineer at the rate to leave residual bitumen emulsion of 0.20 litre/sq.m.
During spraying there shall be no ponding of binder in hollows or depression and any such excess of binder shall be removed.
Portions of kerbs and channels, bridge kerb and railing which will be exposed, shall be suitably protected when applying tack coat.
Application of Slurry Seal Mix
The slurry seal mix will be applied manually. The mix shall be spread uniformly over the road surface with the help of brooms, spades and other suitable tools so as to ensure that all cracks on road surface are properly filled and sealed and resulting surface becomes impervious to ingress of water.
The application of slurry seal mix shall not be done in adverse weather condition.
Bituminous emulsion in drums shall not be allowed to freeze. In case where it is suspected that they could freeze then they shall be removed from site.
Road Maintenance With Fog Seal
Fog seal shall consist of an application of emulsified bitumen without any aggregate cover for sealing the fine hair cracks like shrinkage cracks and alligator cracks.
Slow settingK3 – 60 bituminous emulsion shall be used.
Application Procedure
The area to be applied with fog seal shall be thoroughly cleaned with compressed air, scrubbers etc. The cracks shall be cleaned with pressure air jet to remove all dirt, dust etc.
The fog seal shall be applied at the rate of 0.5-0.9 litre/sq.m using equipment like a pressure tank, that with flexible hose and spraying bar. Traffic shall be allowed on the surface after the seal has set to a non tacky and firm condition so that it is not picked up by the
traffic.
Maintenance of Brick Shoulders / Footpaths
Damages to the brick shoulders/footpaths shall be repaired using materials of equal or higher standard than the original shoulders/footpaths materials.
The damaged area shall be marked out in rectangular shape and shall be excavated with all sides vertical.
If the existing base/subbase is damaged it shall be excavated to the required depth and removed as directed by the Engineer.
The surface of the excavated surface shall be swept clean of dust and loose materials and shall be filled with base/subbase and compacted.
On the prepared base brick shall be laid in the same pattern as the adjoining surfaces and properly tamped.
The repaired surface shall be to the true profile to facilitate free drainage.
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