BBMP asks engineers to follow nine-step methodology for filling potholes

Yesterday, BBMP Special Commissioner Randeep Dev said on Twitter, that all engineers have been instructed to strictly comply with the methodology for filling potholes. BBMP had specified the nine-step methodology for filling potholes last December, following High Court’s orders in PIL No 42927/2015.

Dev said that BBMP is also insisting on geo-tagged photos of potholes before and after patching, to ensure transparency and accountability.

According to Dev, following is the methodology for pothole patching/repair that BBMP engineers have to adhere to.

Step 1: Place traffic control devices

Place traffic cones, flags, flagman to guide and control the traffic movement

Step 2: Marking the defective/pothole area

Sweep away the loose materials of the pothole

Mark the area using chalk to rectangular/square shape

Ensure straight sides and square corners while marking

Step 3: Cutting out defective area

Using Mechanical Cutters

Cutting to be carried out from the centre to sides/edges

Cut down up to stable layer below

Vertical sides are to be ensured during cutting

Step 4: Removal of loose materials

Remove all loose material from the pothole area

Blow out the fine material from the potholes using compressed air

Do not leave any loose material in the pothole or on the pavement surface

Cleaning should be done by using air compressor only

It was instructed to rectify uneven manholes, if any. The Field engineer should see that milling should be done before taking up any asphalting work, so that the existing manhole cover shall match with the road level

Manual cleaning is prohibited

Step 5: Apply Prime coat and tack coat Prime coat

Apply prime coat, if the bottom layer of the pothole is of Wet Mix Macadam

Apply prime coat using Slow Setting – 1 Emulsion (SS1)

Quantity of emulsion to be sprayed is 0.7 to 1.0 kg/sqm

Use sprayers

Do not pour the emulsion into the pothole

Ensure uniform spray of emulsion on sides and bottom surface of pothole

Do not put extra water into emulsion

Tack coat

Apply Tack coat, if the bottom surface is Wet Mix Macadam coated already with prime coat or bituminous surface

Ensure that the application of tack coat on the sides of the cutting edge is also achieved

Apply tack coat using rapid setting emulsion (RS 1)

Quantity of Tack coat

Step 6: Placing of bituminous mix in the pothole

Use squared pointed showed for placing the bituminous mix

Put mix in corners and sides first and then proceed to centre portion

If the pothole is deep, put the mix in layers not exceeding maximum of 75 mm thickness

Place additional layer after compacting the first layer

Step 7: Compaction

Size of roller drum should be smaller than the pothole size

Use vibratory tandem roller only if the pothole size accommodates the roller drum width

Use walk-behind-rollers/plate vibrators for compaction

Compaction to start from corner and edges, and then proceed to central portion

First two passes of the compactor to be static passes, and then remaining passes with vibrations

Check the surface profile using straight edge

Ensure uniform even surface after compaction

Minimum temperature during compaction of hot bituminous mix should not be less than 90 °C

Step 8: Cleaning of pothole patched site

Clean the patch site properly

Dispose the materials at the designated place

Ensure no loose bituminous material near pothole-patched site/pavement

Step 9: Removal of traffic-control devices placed for traffic control during pothole patching