Slurry sealing


Materials
The major materials used for slurry sealing work, but are not limited to the following.
  • Aggregate
  • Filler ( Portland cement )
  • Emulsion ( CSS 1)
  • Water

Equipment
The major equipment used for the slurry sealing, but are not limited to the following.
  • Plate Compactors
  • Tractor & Trailer
  • Other minor tools

Man power
Man power used for the access construction, but are not limited to the following.
  • Technical Officer
  • Skilled Labours
  • Unskilled Labours

Safety Management and Control
Safety precaution will be taken complying with the Road Work Traffic Control Manual. Every precautions will be taken avoid any damages to adjoining properties.
 
Method and Procedures
Following procedure will be used to slurry sealing on the embankment. See flow chart at Appendix A.
All loose material, mud spots, vegetation and other objectionable material will be removed immediately prior to applying the slurry.
After the preparation of existing surface, a tack coat of diluted emulsion using CSS-1 with water in the ratio of 1:3 will apply at a rate of 0.25 l/m2 – 0.5 l/m2, 15- 30 minutes before application the slurry seal.
Materials will be set according to the design and composition of the slurry mix (Table 6.1) and to the grading requirement (Table 6.2) for aggregate.


Design and composition of the slurry mix
Aggregate 98%
Filler 2%
Emulsion 13%
Water 13%


Grading requirement for aggregate.
Sieve size Percentage by mass of total aggregate passing test sieve
3/8 in (9.5mm) 100
No.4 (4.75 mm) 100
No.8 (2.36 mm) 90-100
No.16 (1.18 mm) 65-90
No.30 (600mm) 40-60
No.50 (300mm) 25-42
No.100 (150mm) 15-30
No.200 (075mm) 10-20


The Portland cement will be mixed firstly with the fine aggregate thoroughly using shovels.

Then course aggregate will be add to the above mix and rework.

Half of the estimated quantity of water will add to the aggregate cement mix and will mix to achieve a uniform consistency using shovels.

The material obtained from the previous step will make in to a form of an inverted cone with a depression in the middle. The emulsion (CSS-1) will pour into this depression and mixed immediately using shovels.

Addition of emulsion is done in two equal.

The balance water will be add and mixed thoroughly to achieve slurry of uniform consistency for easy spreading.

Cracks will be sealed using above mix with a rate of application of 3.3-5.4 kg/m2.

30 min minutes after leveling the layer will be compacted using a wooden tamper to obtain a uniform surface with even texture and to expedite the setting time of emulsion.

Then two hour after the commencements of the trials the layer will be compact using a plate vibrator.


Newly constructed area will open for normal vehicular traffic after completion of the above compaction with a minimum speed 15kmph.

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