Download - Ppt Sukhbir
-
8/12/2019 Ppt Sukhbir
1/33
Methodology of HMA
construction
SUKHBIR SINGH
-
8/12/2019 Ppt Sukhbir
2/33
To Be Covered
Hauling
Placement
Compaction
SUKHBIR SINGH
-
8/12/2019 Ppt Sukhbir
3/33
Tandem Axle End Dump Truck
SUKHBIR SINGH
-
8/12/2019 Ppt Sukhbir
4/33
-
8/12/2019 Ppt Sukhbir
5/33
Loading of Hot Mix Asphalt in Truck
SUKHBIR SINGH
-
8/12/2019 Ppt Sukhbir
6/33
Cover the HMA
SUKHBIR SINGH
-
8/12/2019 Ppt Sukhbir
7/33
Reason For Compaction
To prevent further compaction
To provide shear strength or resistanceto rutting
To ensure the mixture is waterproof
To prevent excessive oxidation of the
asphalt binder
SUKHBIR SINGH
-
8/12/2019 Ppt Sukhbir
8/33
-
8/12/2019 Ppt Sukhbir
9/33
Temperatureduring construction
Stage of Work Viscosity of Binder Indicated Temperature
Binder at Mixing Max 2 Poise 165-185
Aggregate Temperature 165-185
Mix Temp. at Plant Max 4 Poise 150-170
Mix Temp. at Laying site
Max 5 Poise
130-160
Rolling Temperature Min 115
SUKHBIR SINGH
-
8/12/2019 Ppt Sukhbir
10/33
Rolling Procedures
Rolling should start as soon as possible afterthe hot mix has been spread.
Rolling consists of three consecutive phases.
1) Breakdown or initial rolling2) Intermediate rolling
3) Finish rolling
SUKHBIR SINGH
-
8/12/2019 Ppt Sukhbir
11/33
Breakdown rolling compacts the material
beyond the compaction imparted by the
paver, to obtain practically all of the needed
density.
Intermediate rolling densifies and seals the
surface.
Finish rolling removes roller marks and other
blemishes left from pervious rolling
SUKHBIR SINGH
-
8/12/2019 Ppt Sukhbir
12/33
-
8/12/2019 Ppt Sukhbir
13/33
If rolling causes material displacement, the
affected area are loosened at once with lutes
or rakes and restored to their original grade
with loose material before being re-rolled.
Heavy equipment, including roller should not
be permitted to stand on the finished surface
it has thoroughly cooled
SUKHBIR SINGH
-
8/12/2019 Ppt Sukhbir
14/33
Rolling freshly placed asphalt
mix is done in the following
order:1. Transverse joints
2. Longitudinal joints3. Initial or breakdown rolling
4. Second or intermediate rolling
5. Finish rolling
SUKHBIR SINGH
-
8/12/2019 Ppt Sukhbir
15/33
Transverse JointsFirst pass in made with a steel-wheeled roller moving along the
longitudinal joint for a short distance.
This operation should be repeated with successive passes covering 150
to 200 mm (6 to 8 in) of fresh material until the entire width of a drive rollsin on the new mix.
If boards are not used, transverse rolling must 150 to 200 mm short of the
outside edge in order to prevent damage to the edge.
SUKHBIR SINGH
-
8/12/2019 Ppt Sukhbir
16/33
Longitudinal Joints
SUKHBIR SINGH
-
8/12/2019 Ppt Sukhbir
17/33
-
8/12/2019 Ppt Sukhbir
18/33
SUKHBIR SINGH
-
8/12/2019 Ppt Sukhbir
19/33
The roller should be shifted to the
previously so that not more then 150 mmrides on the as of newly spread material
This position being shifted graduallyacross the joint until thoroughly
compacted.
Vibration should not be used when
operating on a cold mat.
SUKHBIR SINGH
-
8/12/2019 Ppt Sukhbir
20/33
-
8/12/2019 Ppt Sukhbir
21/33
Overlapping of Roller Passes
SUKHBIR SINGH
-
8/12/2019 Ppt Sukhbir
22/33
Rolling Pattern
SUKHBIR SINGH
-
8/12/2019 Ppt Sukhbir
23/33
For thick lift construction, the rolling process
should start 300 to 375 mm from lower
unsupported edge until certain portion of the
spread is compacted to some stability.
The steel wheeled rollers the operation should
always progress with drive wheel forward in the
direction of paving.
A main reason why breakdown rolling should be
done with the drive wheel is that there ia a some
mor5e direct vertical load applied by this wheel
then tiller wheel.
If the breakdown pass of the roller is made withtiller wheel forward, the pushing force and the
weight is slightly ahead of the vertical, causing
material to push up in front of the wheel.
SUKHBIR SINGH
-
8/12/2019 Ppt Sukhbir
24/33
Wrong Direction of Roller Wheels
SUKHBIR SINGH
-
8/12/2019 Ppt Sukhbir
25/33
Advantages of Pneumatic Tires
Roller
1) They provide more uniform degree of
compaction then Tandem Roller
2) They improve the seal near surface
and decreasing the permeability of layer.
3) They orient the aggregate for greatest
stability.
SUKHBIR SINGH
-
8/12/2019 Ppt Sukhbir
26/33
Finish Rolling
SUKHBIR SINGH
-
8/12/2019 Ppt Sukhbir
27/33
Paving Operation
The feed truck reverse up to the paver andstops few centimetres in fronts of it. As
the paver approaches, its push rollers
touch the rear wheels of truck.
The hear of mix in front of screed should
uniformly spread over the full pave width.
Distance between surface of mat and
lower edge of Auger flights shouldequivalent to roughly 5 times of max size
of aggregate
SUKHBIR SINGH
-
8/12/2019 Ppt Sukhbir
28/33
SUKHBIR SINGH
-
8/12/2019 Ppt Sukhbir
29/33
Auger and Limiting Plates for
Auger tunnel
SUKHBIR SINGH
-
8/12/2019 Ppt Sukhbir
30/33
Head of Mix in front of Screed
SUKHBIR SINGH
-
8/12/2019 Ppt Sukhbir
31/33
Layer thickness and Grain
size of Mix
SUKHBIR SINGH
-
8/12/2019 Ppt Sukhbir
32/33
-
8/12/2019 Ppt Sukhbir
33/33
Extracting A Core
SUKHBIR SINGH