Post on 22-Jan-2018
1 Challenge the future
z
PhD candidate: Mirella Maria Villani
E-mail: m.m.villani@tudelft.nl
Pavement Engineering, TUDelft
Friction in AC mixes:
Experimental and Computational Issues
2 Challenge the future
• In 2012, more than 28000 people died on the roads of the European Union [EU commission, 2013]
• The vehicle accidents, where the state of the road surface plays an important role, are known to account for at least 25% of all European road fatalities [Research Framework 2007-2015, 2006]
Introduction
3 Challenge the future
SKIDSAFE project
WP1 Aggregate characteristics
WP2 Mix surface characteristics
WP6 Skid Resistance
Management Tool
WP5 Hydroplaning
WP3 Tire Pavement Interaction Finite element Modelling WP4
Pavement Surface Skid Resistance
4 Challenge the future
WP1 Aggregate characteristics
WP2 Mix surface characteristics
WP5 Hydroplaning
WP3 Tire Pavement Interaction Finite element Modelling WP4
Pavement Surface Skid Resistance
SKIDSAFE project
WP6 Skid Resistance
Management Tool
5 Challenge the future
• Which are the most important parameters influencing friction?
• How can we improve pavement skid resistance performance
at mix design level?
• How can we monitor skid resistance and its evolution due to progressive polishing?
Research questions
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6
Design, manufacture & validation of the SR-ITD
Skid Resistance Interface Testing Device
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Influence of temperature, result braking test SMA p=0.3 MPa
Skid Resistance Interface Testing Device
8 Challenge the future
Influence of temperature, result braking test SMA p=0.3 MPa
Skid Resistance Interface Testing Device
9 Challenge the future
Influence of temperature, result braking test SMA p=0.3 MPa
Skid Resistance Interface Testing Device
10 Challenge the future
Influence of temperature, result braking test SMA p=0.3 MPa
Skid Resistance Interface Testing Device
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Influence of temperature, result braking test SMA p=0.3 MPa
Skid Resistance Interface Testing Device
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Influence of pressure
Skid Resistance Interface Testing Device
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Skid Resistance Interface Testing Device
Influence of rubber type
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Skid Resistance Interface Testing Device
Influence of surfaces characteristics on friction
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1
Skid Resistance Interface Testing Device
Influence of polishing on friction
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1
Skid Resistance Interface Testing Device
Influence of polishing on friction
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• Speed
• Temperature Rubber characteristics
• Pressure
• AC surface characteristics
Factors influencing friction
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Surface properties
M3D tool for skid resistance evaluation
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Microtextural
and macrotextural
characteristics, MPD, RMS,
MTD, m, ...
Surface characterization parameters
Surface characterization
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Fractal approach
Surface characterization
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Fractal approach
Surface characterization
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Fractal approach
Surface characterization
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Fractal approach
Surface characterization
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2n
z
x 1
C z x z x
Surface characterization
Surface characterization
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H, ,
Surface characterization
Surface characterization
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Surface characterization: different AC mixes
1
Surface characterization
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Surface characterization: different polishing levels
Surface characterization
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+ rubber
characteristics
m
Surface characterization
H, ,
Surface characterization
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V T
3
diss
0 0
E d x dt
Internal dissipated energy
M2D tool for friction evaluation
𝜀
𝜎
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Internal dissipated energy
F
d
V T
3
diss
0 0
E d x dt
M2D tool for friction evaluation
32 Challenge the future
Internal dissipated energy
F
d
V T
3
diss
0 0
E d x dt max
min
-2H-1ω 2
HH 2
N 0 s minω
F Hξ1 ωμ = = ω ''(ω) dω
F 2(2π) σ v 2πvξ ω
E
M2D tool for friction evaluation
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M3D tool for friction evaluation
34 Challenge the future
M3D tool for friction evaluation
35 Challenge the future
M3D tool for friction evaluation
36 Challenge the future
M3D tool for friction evaluation
37 Challenge the future
M3D tool for friction evaluation
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M3D tool for friction evaluation
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• Particular attention should be placed to the influence of
temperature on friction.
• Tools like the M3D can provide a more objective way of evaluating frictional characteristics of AC mixes.
Research answers
40 Challenge the future
• Use of profiles obtained from profilometers for in-time friction evaluation for road monitoring
• Including rolling resistance and noise emission in the M3D tool
• Combine CAPA-3D and M3D tool
Work in progress